Swiss Canine Cancer Registry 1955–2008: Occurrence of the Most Common Tumour Diagnoses and Influence of Age, Breed, Body Size, Sex and Neutering Status on Tumour Development

The epidemiology of mammary tumours in insured female dogs in Sweden

Mammary tumour (MT) is the most common neoplasia in bitches. This study explored the incidence and cause-specific mortality rates of and risk factors for MT in dogs insured by Agria Djurförsäkring in Sweden, 2011-2016. The study population included just over 600,000 dogs, and 13,109 females had veterinary care claims for MT. The incidence rate in females was 157 cases per 10,000 dog-years at risk (95 % confidence interval (CI): 154-160). The breeds at highest risk of MT were the Kerry blue terrier (relative risk (RR) 4.72, 95 % CI 2.58-7.92) and English springer spaniel (RR 3.32, 95 % CI: 3.02-3.63), while the breeds at lowest risk were the German spitz (RR 0.06, 95 % CI: 0.00-0.33) and English bulldog (RR 0.07, 95 % CI: 0.00-0.37). The median age at first MT diagnosis was 8.94 years (interquartile range (IQR) 7.43-10.5). The Dogue de Bordeaux (median age at diagnosis 5.30 years) and Irish wolfhound (6.42 years) were youngest at diagnosis, and the Miniature dachshund (10.9 years) and West Highland white terrier (11.0 years) were oldest. Higher odds of MT were found in bitches with a history of pseudopregnancy (OR 2.10, P < 0.001) and acute mastitis (OR 4.93, P < 0.001). In total, 486 bitches died of MT-related causes at a median age of 9.32 years (IQR 8.37-9.99). The Large Munsterlander had the highest risk of MT-related death (RR 40.3, 95 % CI: 8.28-118.4). In conclusion, MT mainly affected middle-aged to older bitches. Large breed-related differences in the risk of MT and age at diagnosis were found.

Relative Tumour Volume in Canine Oral Melanoma Staging and Prognosis

Melanoma is one of the most common canine oral malignant tumours and is highly aggressive and metastatic, even at the early stages of development. Surgery relies on wide excision of the primary tumour and regional lymphadenectomy, with or without adjuvant therapy. Tumour location and size are important when considering staging, which ultimately affects the curative intent of surgery. Nevertheless, absolute tumour volume (TV) is not related to the vast phenotypic variability within canine breeds. This study aimed to determine the cutoff values of two ratios-tumour-to-head volume (THR) and tumour-to-body volume (TBR)-and assess whether they could be associated with the odds of finding metastasis at presentation and/or the likelihood of achieving tumour-free excision margins. A retrospective case series involving 51 dogs was used to evaluate the preoperative head/neck and chest computed tomography and histopathology of the primary mass and excised lymph nodes. Higher TV, THR% and TBR% values were associated with bone lysis and mitotic count (MC). The Ki67 index was significantly associated with local and distant metastases at presentation, whereas MC was associated with local metastasis alone. Tumour-infiltrated surgical margins were associated with caudally located tumours, regardless of the tumour size. Dogs with lymph node metastasis at presentation were seven times more prone to have local relapse. TV, THR% and TBR% values were positively associated with local lymph node metastasis at presentation. Cutoff values for both TV and TBR% were proposed to predict lymph node metastasis at presentation (TV = 6.423 cm3 and TBR% = 0.043), being supported by post-surgical survival analysis.

Evaluation of canine and feline tumors in Morocco: Results of a prospective observational study of 250 cases (2020-2023)

This work aimed to evaluate the histologic tumor types and patient characteristics of canine and feline neoplasias in Morocco. In a prospective, observational study, 250 tumor samples were collected from veterinary clinics in Morocco. For each case, breed, age, sex, neuter status, and tumor site and histotype were analyzed. Among the 250 tumors, 201 (80.4%) were from dogs and 49 (19.6%) from cats. Most common tumor location in dogs was the reproductive tract (36.8%), followed by skin and soft tissues (27.4%) and mammary gland (14.9%). In cats, most tumors originated from the skin and soft tissues (55.1%), followed by mammary gland (20.4%) and oral cavity (14.3%). Commonest canine histologic tumor types were transmissible venereal tumor (CTVT1) (31.8%) and mammary carcinoma (14.4%). Squamous cell carcinoma (34.7%) and mammary carcinoma (20.4%) represented the most frequent feline neoplasms. Median age of dogs and cats at diagnosis was 7 and 10 years, respectively. Gender distribution was even in dogs; in cats, females were overrepresented. Most cats and about half of dogs were mixed-breed. The evaluated canine and feline neoplasias show differences in their tumor types and patient characteristics when compared to populations from other countries, in part based on the high number of CTVT and - possibly solar-induced -feline skin tumors.

Response to tigilanol tiglate in dogs with mast cell tumors

BACKGROUND

Information regarding response rate to tigilanol tiglate for mast cell tumors in dogs is limited.

OBJECTIVES

Report the response rate and durability of tigilanol tiglate intratumoral treatment in dogs with mast cell tumors presented to veterinary oncologists.

ANIMALS

One hundred forty-nine dogs; 151 individual tumors.

METHODS

Multicenter, retrospective survey-based study. Veterinary oncologists subscribed to the American College of Veterinary Internal Medicine (ACVIM) oncology listserv were solicited for information from dogs treated with tigilanol tiglate. An electronic survey was used to collect information at initial treatment, 1 month and 1 year after treatment.

RESULTS

Most tumors were cutaneous, occurred on the limbs and were cytologically low grade. Seventy-five percent of dogs achieved a complete response after 1 dose of tigilanol tiglate 1 month after treatment. This response was durable at 1 year in 64% of dogs for which data were available (n = 88). Wound formation, an expectation after treatment, occurred after a median of 7 days (range, 1-91 days), with a median wound area of 4.71 cm2 (range, 0.09-100 cm2). Wounds took a median of 30 days to heal completely (range, 14-154 days). A moderate association between tumor volume and wound size was confirmed.

CONCLUSIONS AND CLINICAL IMPORTANCE

Tigilanol tiglate is an effective local treatment option for mast cell tumors in dogs with a predictable clinical course and response. Because of the unique mode of action and clinical course, client education and careful case selection is necessary before electing tigilanol tiglate for local treatment.

Age at Tumor Diagnosis in 14,636 Canine Cases from the Pathology-Based UNIPI Animal Cancer Registry, Italy: One Size Doesn't Fit All

Cancer is the most common cause of death in adult dogs. All dogs would benefit from early diagnosis, but there are no specific guidelines regarding the schedule of cancer screening in companion animals. The aim of this study was to retrospectively evaluate the age at diagnosis in Italian oncological canine patients. A total of 14,636 canine histologically confirmed neoplastic cases were coded according to the Vet-ICD-O-canine-1 and stratified by malignancy, sex, neutering status, breed, cephalic index, body size, and tumor type. Differences in age distribution were analyzed and the influence of these variables on the time of first malignancy diagnosis was assessed using an event history analysis model. The median age at diagnosis for benign and malignant tumors was 9 and 10 years, respectively. Intact and purebred dogs were diagnosed earlier, but the median age differed significantly by breed. The earliest age at diagnosis was recorded for lymphomas and mast cell tumors. The model showed an accelerating effect of large size, brachy- and dolichocephaly, and sexual integrity in female dogs on the time of malignancy diagnosis. Our results confirm that a "one-size-fits-all" approach to cancer screening is not accurate in dogs and provide relevant data that may lead to the establishment of breed-based screening schedules.

Mammary gland, skin and soft tissue tumors in pet cats: findings of the feline tumors collected from 2002 to 2022

Introduction

Cancer is a leading cause of death in cats, and the rate of such disease has been increasing recently. Nonetheless, feline oncology represents an important area of study not only for the health and wellbeing of cats but also for human health since various types of cancer in cats share similarities to those found in humans. Therefore, epidemiological studies on feline oncology may suggest environmental and genetic factors contributing to cancer in cats, which can eventually be translated to improve human cancer care.

Method

To provide an initial understanding of the epidemiology of feline neoplasms, a descriptive study was undertaken using a dataset documenting cases of feline cancer gathered from the Liguria region (northwest Italy) spanning from 2002 to 2022. The database includes tumor location, morphological codes of the International Classification of Diseases for Oncology, 3rd Edition (ICD-O-3), feline's breed, sex, neuter status, date of birth, date of diagnosis, national territorial unit code of the town of the owner's residence, and an alphanumeric string uniquely identifying the owner's surname.

Results and discussion

The dataset involves a population of 4,399 cats, including 3,195 females (1,425 neutered) and 1,204 males (750 neutered). Our results indicate that mammary gland tumors are the most represented tumors in the female population, while soft tissue and skin cancers appear to have a higher abundance in the male population during the periods investigated (2002-2022). Moreover, Poisson regression analysis showed that not neutered female cats have a significantly increased risk of developing mammary gland tumors compared to the neutered female population [proportional morbidity ratio (PMR) neutered vs. not neutered = 0.58, 95% CI: 0.47-0.72]; meanwhile, for both sexes, for soft tissue and skin tumors, being neutered appears to be a risk factor (PMR neutered vs. not neutered = 2.26, 95% CI: 1.86-2.73; PMR neutered vs. not neutered = 1.16, 95% CI: 0.89-1.51). Finally, the evaluation of the Ligurian municipalities pollution, based on wild boars data (i.e., biomonitors), which coexisted with cats, was correlated to cancer development for all the tumors investigated (in polluted areas, estimated PMRs ranged from 42.61 to 80.13, 95% CI: 29.94-105.11). Overall, the data presented here suggest the use of the feline population as a possible animal model for human health, i.e., sentinel.

A Review on Canine and Human Soft Tissue Sarcomas: New Insights on Prognosis Factors and Treatment Measures

Soft tissue sarcomas (STSs) represent a diverse group of tumors arising from mesenchymal cells, affecting both humans and animals, including dogs. Although STSs represent a class of rare tumors, especially in humans, they pose significant clinical challenges due to their potential for local recurrence and distant metastasis. Dogs, as a model for human STSs, offer several advantages, including exposure to similar environmental risk factors, genetic diversity among breeds, and the spontaneous development of tumors. Furthermore, canine tumors closely mimic the heterogeneity and complexity of human tumors, making them valuable for research into disease progression and treatment effectiveness. Current treatment approaches for STSs in both dogs and humans primarily involve surgery, radiation therapy, and chemotherapy, with treatment decisions based on tumor characteristics and patient factors. However, the development of novel therapeutic strategies is essential, given the high failure rate of new drugs in clinical trials. To better design new tailored treatments, comprehension of the tumor microenvironment (TME) is fundamental, since it plays a crucial role in STS initiation and progression by modulating tumor behavior, promoting angiogenesis, and suppressing immune responses. Notably, TME features include cancer-associated fibroblasts (CAFs), extracellular matrix (ECM) alterations, and tumor-associated macrophages (TAMs) that, depending on their polarization state, can affect immune responses and thus the patient's prognosis. In this review, new therapeutical approaches based on immunotherapy will be deeply explored as potential treatment options for both dogs and humans with STSs. In conclusion, this review provides an overview of the current understanding of STSs in dogs and humans, emphasizing the importance of the TME and potential treatment strategies.

Bringing the Genomic Revolution to Comparative Oncology: Human and Dog Cancers

Dogs are humanity's oldest friend, the first species we domesticated 20,000-40,000 years ago. In this unequaled collaboration, dogs have inadvertently but serendipitously been molded into a potent human cancer model. Unlike many common model species, dogs are raised in the same environment as humans and present with spontaneous tumors with human-like comorbidities, immunocompetency, and heterogeneity. In breast, bladder, blood, and several pediatric cancers, in-depth profiling of dog and human tumors has established the benefits of the dog model. In addition to this clinical and molecular similarity, veterinary studies indicate that domestic dogs have relatively high tumor incidence rates. As a result, there are a plethora of data for analysis, the statistical power of which is bolstered by substantial breed-specific variability. As such, dog tumors provide a unique opportunity to interrogate the molecular factors underpinning cancer and facilitate the modeling of new therapeutic targets. This review discusses the emerging field of comparative oncology, how it complements human and rodent cancer studies, and where challenges remain, given the rapid proliferation of genomic resources. Increasingly, it appears that human's best friend is becoming an irreplaceable component of oncology research.

Elevated levels of IL-12/IL-23p40 in Nova Scotia Duck Tolling Retrievers with autoimmune disease and lymphoma

The Nova Scotia Duck Tolling Retriever (NSDTR) is predisposed to immune mediated rheumatic disease (IMRD), steroid-responsive meningitis-arteritis (SRMA) and certain forms of cancer. Cytokines are the main regulators of the immune system. Interleukin 2 is a cytokine involved in activation of T regulatory cells, playing a role in central tolerance and tumor immunity. Interleukin 12 and interleukin 23 share the same subunit, p40, and are both pro-inflammatory cytokines. The aim of this study was to compare levels of IL-2 in healthy NSDTRs to those with cancer or autoimmune disease and to compare levels of IL-12/IL-23p40 in healthy NSDTRs and beagles versus NSDTRs with cancer or autoimmune disease. 62 dogs were included in the analysis of IL-12/IL-23p40; healthy NSDTRs (n = 16), healthy beagles (n = 16), NSDTRs autoimmune (n = 18) and NDSTRs lymphoma/mastocytoma (n = 12) and 68 dogs for IL-2; healthy (n = 20), autoimmune (n = 36) and lymphoma/mastocytoma/adenocarcinoma (n = 12). NSDTRs with autoimmune disease had higher levels of IL-12/IL-23p40 compared to healthy dogs (p = 0.008). NSDTRs with lymphoma also had higher levels of IL-12/IL-23p40 compared to healthy NSDTRs (p = 0.002). There was no difference in levels of IL-2 between healthy and diseased NSDTR. Statistical analysis was performed using Bonferroni corrections for multiple testing. These findings can contribute to the knowledge of autoimmune disease and cancer in dogs.

Canine Euthanasia's Trend Analysis during Thirty Years (1990-2020) in Italy: A Veterinary Hospital as Case Study

This study aimed to investigate changes in the number of, and reasons for, requests for dogs' euthanasia over the last thirty years. Data (breed, age, gender, neuter status, manner, and cause of death) from dogs' euthanasia registered between 1990 and 2020 in a small animals' veterinary hospital were analyzed. The overall period examined has been split into two terms (T1 = 1990-2004 and T2 = 2005-2020) considering the introduction and enforcement of Law 189/2004. During the whole period examined, a significant increasing trend in euthanasia cases has been recorded (p = 0.027). Comparing the two terms, we observed significant differences regarding variables such as age, breed, reproductive status, and ownership. The number of euthanized dogs was significantly higher in T1 than in T2. Dogs euthanized in T2 were older than dogs in T1. A high percentage of the euthanized dogs were crossbred and stray dogs. Additionally, the number of neutered/spayed dogs was significantly higher. Regarding the cause of death, a significantly higher percentage of neoplastic processes was detected in T2. The data here reported suggest a potential influence of Law 189/2004. This law in Italy has proven to be a legal milestone that has influenced the decision-making process between euthanasia and natural death.

Incidence rates of the most common canine tumors based on data from the Swiss Canine Cancer Registry (2008 to 2020)

Monitoring neoplasms in standardized registries facilitates epidemiologic studies of risk factors for tumor development and predisposition. In an observational study, we determined incidence rates (IR) and malignant tumor incidence rate ratios (IRR) by age, sex, and breed in Swiss dogs using demographic data from the official Swiss dog registration database Amicus. The dataset analyzed included 54'986 tumors diagnosed by histology and cytology in four Swiss veterinary pathology laboratories between 2008 and 2020. Diagnoses were coded according to the Vet-ICD-O-canine-1 system. Most tumors occurred in the skin (n = 19'045; 34.64%), soft tissues (n = 11'092; 20.17%), and mammary glands (n = 7'974; 14.50%). The IRs for all and for malignant tumors were 775/100'000 dog-years at risk (95%CI 764-777) and 338/100'000 dog-years at risk (95%CI 333-342), respectively. Females (850; 95%CI 834-853) had a higher overall tumor IR than males (679; 95%CI 666-684). The highest tumor IR was found at 11 years of age (1'857; 95%CI 1'780-1'867). Potential novel breed-specific predispositions were uncovered, with high IRs for several benign and malignant tumors in Polski Owczarek Nizinnys (overall IR: 3'303; 95%CI 2'502-3'864) and high IRs for malignant tumors in Russian Black Terriers (melanomas: 345; 95%CI 138-708), Field Spaniels (adenocarcinomas: 376; CI95% 138-817), Dogo Argentinos (mast cell tumors: 844; CI95% 591-1'169), King Charles Spaniels and Manchester Terriers (lymphomas: 319; CI95% 137-627 and 302; CI95% 98-704, respectively), Landseers (osteosarcomas: 74; CI95% 15-216), Bouvier des Flandres (hemangiosarcomas: 127; CI95% 26-371), and Bearded Collies and Cane Corso Italianos (gliomas: 91; CI95% 45-162 and 34; CI95% 7-99, respectively). Nordic hunting dogs had the highest (8.08; CI95% 3.55-16.7) and Chihuahueno the lowest cancer IRRs (0.42; 95%CI 0.31-0.57) compared to mixed breeds. In conclusion, the calculated IRs and IRRs revealed previously unknown predisposing factors, including novel breed-specific susceptibilities. The results may have implications for cancer screening, diagnostic work-up, breeding management and oncologic and translational research.

Pathological Characterization and Risk Factors of Splenic Nodular Lesions in Dogs (Canis lupus familiaris)

In dogs, the spleen is a secondary lymphoid organ that can be affected by both neoplastic and non-neoplastic nodules. In general, few studies relate histopathological diagnosis to tumor size and the number of nodules in spleen biopsies. Some of these studies are inconclusive regarding the difference between neoplastic and non-neoplastic lesions and have small sample sizes or do not consider all splenic lesions. This study aimed to characterize splenic masses and determine risk factors for spleen tumors in dogs. A total of 507 histological reports corresponding to the diagnosis of splenic lesions in dogs from a private laboratory of animal pathology in the Metropolitan Region, Chile, were used. Data were analyzed by descriptive statistics and multiple logistic regression. The most frequent neoplastic and non-neoplastic diagnoses were hemangiosarcoma and hyperplasia, respectively. Most of the cases occurred in male (265 cases, 52.3%), senior (421 cases, 83%), and purebred individuals (342 cases, 67.5%). The most affected breeds were the Cocker Spaniel, German Shepherd, and Labrador Retriever. The most frequent lesion was a single nodule. The variables that exhibited a greater risk for the presentation of splenic neoplasia were male sex (odds ratio (OR) = 16.21; 95% confidence interval (CI) 1.741-150.879; p = 0.014), the presence of two or more splenic nodules (OR = 3.94; 95% CI 2.168-7.177; p < 0.001), an increase in nodule size greater than 2 cm (OR for quartiles 2, 3 and 4 of 2.2; 95% CI 1.036-4.941; p = 0.041, 2.9; 95% CI 1.331-6.576; p = 0.008, and 3.6; 95% CI 1.562-8.499; p = 0.003, respectively), and increasing age (OR = 1.23; 95% CI 1.048-1.436; p = 0.011). On the other hand, males exhibited a lower risk as age increases (OR = 0.76; 95% CI 0.615-0.928; p = 0.008). In conclusion, this study identified that males, multinodular presentation, nodule size, and age are risk factors for the occurrence of splenic neoplasia in dogs, knowledge that will contribute to the diagnostic management of dogs with spleen lesions.

Cancer detection in dogs using rapid Raman molecular urinalysis

Introduction

The presence of cancer in dogs was detected by Raman spectroscopy of urine samples and chemometric analysis of spectroscopic data. The procedure created a multimolecular spectral fingerprint with hundreds of features related directly to the chemical composition of the urine specimen. These were then used to detect the broad presence of cancer in dog urine as well as the specific presence of lymphoma, urothelial carcinoma, osteosarcoma, and mast cell tumor.

Methods

Urine samples were collected via voiding, cystocentesis, or catheterization from 89 dogs with no history or evidence of neoplastic disease, 100 dogs diagnosed with cancer, and 16 dogs diagnosed with non-neoplastic urinary tract or renal disease. Raman spectra were obtained of the unprocessed bulk liquid urine samples and were analyzed by ISREA, principal component analysis (PCA), and discriminant analysis of principal components (DAPC) were applied using the Rametrix®Toolbox software.

Results and discussion

The procedure identified a spectral fingerprint for cancer in canine urine, resulting in a urine screening test with 92.7% overall accuracy for a cancer vs. cancer-free designation. The urine screen performed with 94.0% sensitivity, 90.5% specificity, 94.5% positive predictive value (PPV), 89.6% negative predictive value (NPV), 9.9 positive likelihood ratio (LR+), and 0.067 negative likelihood ratio (LR-). Raman bands responsible for discerning cancer were extracted from the analysis and biomolecular associations were obtained. The urine screen was more effective in distinguishing urothelial carcinoma from the other cancers mentioned above. Detection and classification of cancer in dogs using a simple, non-invasive, rapid urine screen (as compared to liquid biopsies using peripheral blood samples) is a critical advancement in case management and treatment, especially in breeds predisposed to specific types of cancer.

Current understanding of comparative pathology and prospective research approaches for canine hemangiosarcoma

Hemangiosarcoma (HSA) is a malignant tumor originating from endothelial cells. HSA typically develops in dogs, but is rare in other animals, including humans. Although surgery and chemotherapy are conventional treatments for HSA, neither treatment can significantly improve patient prognosis. To develop novel and effective therapeutics, a deeper understanding of HSA pathogenesis must be acquired. However, the limited research tools for HSA have been unable to make a breakthrough; therefore, it is crucial to widely utilize or establish novel research tools such as patient-derived xenograft models, organoids, and chicken embryo xenograft models. The pathogenesis of the human counterpart of HSA, angiosarcoma (AS), also remains incompletely understood, preventing the extrapolation of findings from humans to dogs, unlike other diseases. In this review, we summarize the clinicopathological and morphological features of HSA, and then we discuss the current understanding of the molecular pathology of HSA. Finally, we highlight promising research tools that may accelerate HSA basic research toward developing novel therapeutics. We also briefly summarize AS to help researchers comprehend HSA from the perspective of comparative pathology.

English Cocker Spaniels under primary veterinary care in the UK: disorder predispositions and protections

BACKGROUND

The English Cocker Spaniel (ECS) is one of the most popular dog breeds in the UK but information on disorder predisposition and protection is limited. Using anonymised veterinary clinical data from the VetCompass™ Programme, this study aimed to compare disorder predisposition and protection between the ECS and the remaining dogs under primary veterinary care in the UK during 2016. Electronic patient records for random samples of ECS and non-ECS were reviewed. The most common disorders diagnosed during 2016 were extracted and compared using multivariable logistic regression, controlling for confounders.

RESULTS

The analysis included random samples of 2510/10,313 (24.3%) ECS and 7813/326,552 (2.39%) non-ECS. After accounting for confounding by age, sex, bodyweight within breed-sex, insurance status and veterinary practice group, the ECS had increased odds of 21/43 (48.85%) disorders at fine-level precision, with highest odds for aural discharge (odds ratio (OR) 14.66, 95% confidence interval (CI): 7.73-30.90, P <  0.001) and keratoconjunctivitis sicca (OR 7.64, 95% CI: 4.33-14.14, P <  0.001) and lowest odds for atopic dermatitis (OR 0.14, 95% CI: 0.05-0.31, P <  0.001) and allergy (OR 0.14, 95% CI: 0.06-0.28, P <  0.001).

CONCLUSIONS

This study provides evidence for strong predisposition to aural and ocular disorders and protection from hypersensitivity disorders in the ECS. These results can aid dog owners, breeders, and veterinarians to better monitor health in ECS, and promote earlier diagnosis with improved prognosis. Further, the results can help breeding organisations establish key priorities the health-based reforms of the ECS.

The effect of neuter status on longevity in the Rottweiler dog

Surgical sterilization or neutering of dogs is a commonly performed procedure in veterinary practices in many countries. In recent decades, concerns have been raised regarding possible side effects of neutering, including increased risk of certain neoplastic, musculoskeletal and endocrinological conditions. Considering that age serves as a significant confounding factor for some of these conditions, evaluating longevity statistics could provide valuable insights into the impact of neutering. The aim of this study was to compare longevity between neutered and sexually intact male and female Rottweilers, using electronic patient records collected by the VetCompass Australia database. Male and female Rottweilers neutered before 1 year of age (n = 207) demonstrated an expected lifespan 1.5 years and 1 year shorter, respectively, than their intact counterparts (n = 3085; p < 0.05). Broadening this analysis to include animals neutered before the age of 4.5 years (n = 357) produced similar results.

Canine Mammary Cancer: State of the Art and Future Perspectives

Mammary cancer is the most frequently diagnosed neoplasia in women and non-spayed female dogs and is one of the leading causes of death in both species. Canines develop spontaneous mammary tumors that share a significant number of biological, clinical, pathological and molecular characteristics with human breast cancers. This review provides a detailed description of the histological, molecular and clinical aspects of mammary cancer in canines; it discusses risk factors and currently available diagnostic and treatment options, as well as remaining challenges and unanswered questions. The incidence of mammary tumors is highly variable and is impacted by biological, pathological, cultural and socioeconomic factors, including hormonal status, breed, advanced age, obesity and diet. Diagnosis is mainly based on histopathology, although several efforts have been made to establish a molecular classification of canine mammary tumors to widen the spectrum of treatment options, which today rely heavily on surgical removal of tumors. Lastly, standardization of clinical study protocols, development of canine-specific biological tools, establishment of adequate dog-specific disease biomarkers and identification of targets for the development of new therapies that could improve survival and have less adverse effects than chemotherapy are among the remaining challenges.

Identifying the Risk Factors for Malignant Mammary Tumors in Dogs: A Retrospective Study

Mammary cancer is one of the main causes of death in female dogs worldwide, considering that many risk factors are involved in its development. This study aimed to elucidate the relationship between epidemiological and clinical risk factors with the histopathological diagnosis of malignant mammary tumors in dogs treated at the Veterinary Hospital of the Federal University of Uberlândia, which has one of the first veterinary oncology services in Brazil. A retrospective matched case-control study was conducted to identify risk factors for the development of malignant mammary tumors in dogs. The variables analyzed were size dog, breed, housing, type of diet, and body score. Potential risk factors were selected by univariate analysis (p < 0.25) before multivariate forward binary logistic regression. The most frequent benign tumor was the benign mixed tumor (35.2%), and the most frequent malignant tumor was the mixed carcinoma (27.4%). Size dog, breed, housing, and overweight are predictors of malignant mammary tumors in dogs. The highest risk of developing malignant mammary tumors is associated with large female dogs, Yorkshire or Poodle breeds, living outside the home, or being overweight.

Deciphering Stromal Changes between Metastatic and Non-metastatic Canine Mammary Carcinomas

Cancer-associated stroma (CAS) is widely recognized to influence development and progression of epithelial tumours including breast cancer. Canine mammary tumours (CMTs) such as simple canine mammary carcinomas represent valuable models for human breast cancer also with respect to stromal reprogramming. However, it remains unclear whether and how CAS changes in metastatic tumours compared to non-metastatic ones. To characterize stromal changes between metastatic and non-metastatic CMTs and identify potential drivers of tumour progression, we analysed CAS and matched normal stroma from 16 non-metastatic and 15 metastatic CMTs by RNA-sequencing of microdissected FFPE tissue. We identified 1438 differentially regulated genes between CAS and normal stroma, supporting previous results demonstrating stromal reprogramming in CMTs to be comparable with CAS in human breast cancer and validating deregulation of pathways and genes associated with CAS. Using primary human fibroblasts activated by treatment with TGFβ, we demonstrate some of the strongest expression changes to be conserved in fibroblasts across species. Furthermore, we identify 132 differentially expressed genes between CAS from metastatic and non-metastatic tumours, with strong changes in pathways including chemotaxis, regulation of apoptosis, immune response and TGFβ signalling and validate deregulation of several targets using RT-qPCR. Finally, we identify specific upregulation of COL6A5, F5, GALNT3, CIT and MMP11 in metastatic CAS, suggesting high stromal expression of these targets to be linked to malignancy and metastasis of CMTs. In summary, our data present a resource supporting further research into stromal changes of the mammary gland in relation to metastasis with implications for both canine and human mammary cancer.

Comparative Study of Digital Squamous Cell Carcinoma in Giant, Standard, and Miniature Schnauzers

In schnauzers, a breed predisposition to squamous cell carcinoma of the digit (dSCC) is well known. The aim of this study was to compare the clinical and macroscopic findings of dSCCs in giant (GSs), standard (SSs), and miniature schnauzers (MSs).

METHODS

Pathology reports of 478 dSCCs from 417 schnauzers (227 GSs, 174 SSs, and 16 MSs) were retrospectively evaluated.

RESULTS

The MSs were older than the SSs and GSs (p ≤ 0.01). The male GSs were predisposed to dSCC (p < 0.05). In the GSs, the nodular dSCCs were larger than in the MSs (p ≤ 0.05) and SSs (p ≤ 0.001). The digital SCCs were mostly diagnosed at the forelimbs, especially at digits 1, 2, and 5. At the hindlimbs, the affected toes differed between the GSs and SSs. Multiple dSCCs were more common in SSs than in GSs (p = 0.003). If dSCC was the cause of death, the survival time was shorter than in dogs dying from other diseases (p = 0.004). Metastases occurred in 20% of the cases and led to a significantly shorter survival time in both the GSs and SSs (p < 0.001).

CONCLUSIONS

The results showed various differences in the dSCC depending on the size variant of the schnauzer.

Demography and disorders of English Cocker Spaniels under primary veterinary care in the UK

BACKGROUND

The English Cocker Spaniel (ECS) is a common family dog in the UK. This study aimed to describe demography, morbidity, and mortality in ECS under primary veterinary care in the UK during 2016 using data from the VetCompass™ Programme. This study hypothesised that the prevalence of aggression is higher in male than female ECS, and higher in solid-coloured than bi-coloured ECS.

RESULTS

English Cocker Spaniels comprised 10,313/336,865 (3.06%) of dogs under primary veterinary care during 2016. The median age was 4.57 years (inter-quartile range (IQR) 2.25-8.01) and the median adult bodyweight was 15.05 kg (IQR 13.12-17.35). The annual proportional birth rate was relatively stable between 2.97-3.51% from 2005-2016. The most common specific diagnoses were periodontal disease (n = 486, prevalence 20.97%, 95% confidence interval (CI): 19.31-22.62), otitis externa (n = 234, 10.09%, 95% CI: 8.87-11.32), obesity (n = 229, 9.88%, 95% CI: 8.66-11.09), anal sac impaction (n = 187, 8.07%, 95% CI: 6.96-9.18), diarrhoea (n = 113, 4.87%, 95% CI: 4.00-5.75), and aggression (n = 93, 4.01%, 95% CI: 3.21-4.81). The prevalence of aggression was higher in males (4.95%) than in females (2.87%) (P = 0.015) and in solid-coloured (7.00%) than in bi-coloured dogs (3.66%) (P = 0.010). The median age at death was 11.44 years (IQR 9.46-13.47) and the most common grouped causes of death were neoplasia (n = 10, 9.26%, 95% CI: 3.79-14.73), mass-associated disorders (n = 9, 8.33%, 95% CI: 4.45-15.08), and collapse (n = 8, 7.41%, 95% CI: 3.80-13.94).

CONCLUSIONS

Periodontal disease, otitis externa, and obesity are identified as the most common health issues for ECS, and neoplasia and mass-associated disorders as the most common reasons for death. The prevalence of aggression was higher in males and solid-coloured dogs. The results can aid veterinarians in giving evidence-based health and breed choice information to dog owners and highlights the importance of thorough oral examination and body condition score evaluation during routine veterinary examination of ECS.

Associations Between Dog Breed and Clinical Features of Mammary Epithelial Neoplasia in Bitches: an Epidemiological Study of Submissions to a Single Diagnostic Pathology Centre Between 2008-2021

Mammary cancer is one of the most common neoplasms of dogs, primarily bitches. While studies have been carried out identifying differing risk of mammary neoplasia in different dog breeds, few studies have reported associations between dog breeds and clinical features such as number of neoplastic lesions found in an individual case or the likelihood of lesions being benign or malignant. Such epidemiological studies are essential as a foundation for exploring potential genetic drivers of mammary tumour behaviour. Here, we have examined associations between breed, age and neuter status and the odds of a diagnosis of a mammary epithelial-origin neoplastic lesion (as opposed to any other histopathological diagnosis from a biopsied lesion) as well as the odds of a bitch presenting with either a single mammary lesion or multiple lesions, and the odds that those lesions are benign or malignant. The study population consisted of 129,258 samples from bitches, including 13,401 mammary epithelial neoplasms, submitted for histological assessment to a single histopathology laboratory between 2008 and 2021.In multivariable analysis, breed, age and neuter status were all significantly associated with the odds of a diagnosis of a mammary epithelial-origin neoplastic lesion. Smaller breeds were more likely to receive such a diagnosis. In cases diagnosed with a mammary epithelial neoplasm, these three factors were also significantly associated with the odds of diagnosis with a malignant lesion and of diagnosis with multiple lesions. Notably, while neutered animals were less likely to have a mammary epithelial neoplasm diagnosed, and were less likely to have multiple neoplasms, they were more likely to have malignant disease. Exploration of the patterns of risk of developing malignant disease, or multiple lesions, across individual breeds showed no breed with increased odds of both outcomes. Breeds with altered odds compared to the Crossbreed baseline were either at increased risk of malignant disease and decreased risk of multiple lesions, or vice versa, or they were at significantly altered odds of one outcome with no change in the other outcome. Our analysis supports the hypothesis that age, neuter status and intrinsic biological and genetic factors all combine to influence the biological heterogeneity of canine mammary neoplasia.

Frontal sinus carcinoma in forty-one dogs (2001-2022)

Reports on canine frontal sinus carcinomas (FSCs) are scarce. This retrospective review of 41 dogs with FSC (2001-2022) describes demographic and clinical characteristics of canine FSC and reports the clinical experience and overall survival following treatment with toceranib phosphate (TOC) and meloxicam in 10 cases. Median age at diagnosis was 10.6 years (range: 6.5-15.4 years). There was a male-to-female-ratio of 2.4:1. The most common breeds were Jack Russell Terriers (JRT) (n = 7; 17.1%) and Rottweilers (n = 3, 7.3%). Mesocephalic breeds (70.6%) were most commonly affected, brachycephalics accounted for 8.8%. The most frequent clinical signs included skull deformation dorsomedial to the eye (87.5%), pain/head-shyness (40.0%), ocular (22.5%)/nasal (17.5%) discharge, and exophthalmos (17.5%). Duration of symptoms prior to diagnosis varied from a few days to 9 months. There were no neurological signs at initial presentation despite imaging evidence of osteolysis of the lamina interna of the frontal bone in most dogs (69.4%). In 11.5%, pulmonary changes suggestive of metastasis or concurrent primary pulmonary neoplasia were present. Tumour types included squamous cell carcinoma (58.5%), unspecified carcinoma (29.3%), and adenocarcinoma (9.8%). Ten dogs were treated with TOC (median 2.8 mg/kg EOD or three times per week) and meloxicam (0.1 mg/kg, EOD) (TOC-M), resulting in subjective regression of skull deformity in 8/10 (80.0%) patients. Overall median survival time with TOC-M was 183.5 days (range: 120-434 days). FSCs typically present with skull deformation, but no overt neurological signs. Male dogs and JRT may be overrepresented. The use of TOC-M in FSC appears promising and warrants further prospective evaluation.

Age at cancer diagnosis by breed, weight, sex, and cancer type in a cohort of more than 3,000 dogs: Determining the optimal age to initiate cancer screening in canine patients

The goal of cancer screening is to detect disease at an early stage when treatment may be more effective. Cancer screening in dogs has relied upon annual physical examinations and routine laboratory tests, which are largely inadequate for detecting preclinical disease. With the introduction of non-invasive liquid biopsy cancer detection methods, the discussion is shifting from how to screen dogs for cancer to when to screen dogs for cancer. To address this question, we analyzed data from 3,452 cancer-diagnosed dogs to determine the age at which dogs of certain breeds and weights are typically diagnosed with cancer. In our study population, the median age at cancer diagnosis was 8.8 years, with males diagnosed at younger ages than females, and neutered dogs diagnosed at significantly later ages than intact dogs. Overall, weight was inversely correlated with age at cancer diagnosis, and purebred dogs were diagnosed at significantly younger ages than mixed-breed dogs. For breeds represented by ≥10 dogs, a breed-based median age at diagnosis was calculated. A weight-based linear regression model was developed to predict the median age at diagnosis for breeds represented by ≤10 dogs and for mixed-breed dogs. Our findings, combined with findings from previous studies which established a long duration of the preclinical phase of cancer development in dogs, suggest that it might be reasonable to consider annual cancer screening starting 2 years prior to the median age at cancer diagnosis for dogs of similar breed or weight. This logic would support a general recommendation to start cancer screening for all dogs at the age of 7, and as early as age 4 for breeds with a lower median age at cancer diagnosis, in order to increase the likelihood of early detection and treatment.

Immunohistochemical Expression of Tensin-4/CTEN in Squamous Cell Carcinoma in Dogs

C-terminal tensin-like (tensin-4/TNS4/CTEN) is the fourth member of the tensin family, frequently described as displaying oncological functions, including cellular migration, invasion, adhesion, growth, metastasis, epithelial to mesenchymal transition, and apoptosis, in several different types of cancer. To investigate, for the first time, the clinical significance of CTEN in squamous cell carcinoma (SCC) of dogs, we studied a total of 45 SCC sections from various dog breeds. The mean age of the affected dogs was 8.9 ± 3.6 years. Immunohistochemistry confirmed strong cytoplasmatic CTEN expression in the basal layer of the epidermis next to the tumor. We detected high CTEN expression associated with the highest grade of the tumor (grade III) and observed 100% of immunopositivity for this tumor grading (p < 0.0001). These data suggest that CTEN is an oncogene in SCC of dogs and a promising biomarker and a therapeutic target for dogs affected by SCC.

Tumour Incidence in Dogs in Germany: a Retrospective Analysis of 109,616 Histopathological Diagnoses (2014-2019)

Characterization of a tumour entity is based on the precise histopathological diagnosis taking into account the signalment of the diseased animal. The present study is a comprehensive, up-to-date statistical investigation on the type, frequency and breed distribution of neoplasia in dogs in Germany. The histopathological datasets of 109,616 German canine tissue samples (2014-2019) were processed and statistically examined in retrospect. Non-neoplastic diseases were found in 38,650 samples (35.3%) and 70,966 neoplasms (64.7%) were diagnosed. The most common neoplasms were mammary tumours (21.9%), benign epithelial skin tumours (15.4%), mast cell tumour (9.7%), histiocytoma (7.0%), soft tissue sarcoma (5.8%), lipoma (5.8%), melanocytic tumours (5.2%) and odontogenic tumours (4.7%). In general, Beagles, Magyar Vizslas, Boxers, Schnauzers, Spaniels, French Bulldogs and Golden Retrievers had an increased risk of neoplasia (odds ratio 1.17-1.46; all: P ≤0.001) compared with crossbreed dogs. In particular, Boxers, Golden Retrievers, Rottweilers and Schnauzers were often affected by malignant neoplasms, whereas some breeds (eg, West Highland White Terrier, Magyar Vizsla, Chihuahua, Dachshund and Yorkshire Terrier) were frequently affected by numerous benign tumour types. Despite the known risk of haemangiosarcoma in German Shepherd Dogs, other malignant tumours were rare in this breed. Depending on the type of tumour, some purebred dog breeds can have an increased, reduced or identical risk for certain neoplasms compared with crossbreeds. Discussion of breed predispositions to tumour diseases must therefore be conducted critically and with a view to clinical relevance.

The Italian Network of Laboratories for Veterinary Oncology (NILOV) 2.0: Improving Knowledge on Canine Tumours

Simple Summary

Advances in cancer research are crucial, and pet oncology can improve the knowledge in several ways. Dogs are not only models of specific naturally occurring tumours but can also be sentinels of environmental exposures to carcinogenic substances, as they share the same environment with their owners. The purpose of this work was to describe the data collected by The Italian Network of Laboratories for Veterinary Oncology in the first 9 years of activity (2013–2021) and to evaluate their potential epidemiological significance. Frequencies of tumour sites in dogs were described, analysed and compared, considering several risk factors (breed, sex, period and region of residence). These observations allowed us to highlight differences not only in the site of occurrence of some tumours but also to formulate hypotheses on the potential role of some risk factors, e.g., neutering/spaying or geographical location. In our opinion, the results of this study confirm the importance of initiating and consolidating animal cancer registration initiatives that would facilitate the possibility of conducting multicentric collaborative studies to deepen the knowledge of the epidemiology of tumours in dogs and, from a comparative perspective, in humans.

Abstract

Advances in tumour research are crucial, and comparative oncology can improve the knowledge in several ways. Dogs are not only models of specific naturally occurring tumours but can also be sentinels of environmental exposures to carcinogens, as they share the same environment with their owners. The purpose of this work was to describe the data collected by The Italian Network of Laboratories for Veterinary Oncology in the first 9 years of activity (2013–2021) and to evaluate their potential epidemiological significance. Frequencies of tumour topographies and main morphologies in dogs were described, analysed and compared, calculating age-adjusted proportional morbidity ratios and considering several risk factors (breed, sex, period and region of residence). These observations allowed us to highlight differences not only in morphology and topography of some tumours but also to formulate hypotheses on the potential role of some risk factors, e.g., neutering/spaying or geographical location. In our opinion, the results of this case series confirm the importance of initiating and consolidating animal cancer registration initiatives that would facilitate the possibility of conducting multicentric collaborative studies to deepen the knowledge of the epidemiology of tumours in dogs from a comparative perspective.

Application of Bayesian Regression for the Identification of a Catchment Area for Cancer Cases in Dogs and Cats

Research on cancer in dogs and cats, among other diseases, finds an important source of information in registry data collected from hospitals. These sources have proved to be decisive in establishing incidences and identifying temporal patterns and risk factors. However, the attendance of patients is not random, so the correct delimitation of the hospital catchment area (CA) as well as the identification of the factors influencing its shape is relevant to prevent possible biases in posterior inferences. Despite this, there is a lack of data-driven approaches in veterinary epidemiology to establish CA. Therefore, our aim here was to apply a Bayesian method to estimate the CA of a hospital. We obtained cancer (n = 27,390) and visit (n = 232,014) registries of dogs and cats attending the Veterinary Medical Teaching Hospital of the University of California, Davis from 2000 to 2019 with 2,707 census tracts (CTs) of 40 neighboring counties. We ran hierarchical Bayesian models with different likelihood distributions to define CA for cancer cases and visits based on the exceedance probabilities for CT random effects, adjusting for species and period (2000-2004, 2005-2009, 2010-2014, and 2015-2019). The identified CAs of cancer cases and visits represented 75.4 and 83.1% of the records, respectively, including only 34.6 and 39.3% of the CT in the study area. The models detected variation by species (higher number of records in dogs) and period. We also found that distance to hospital and average household income were important predictors of the inclusion of a CT in the CA. Our results show that the application of this methodology is useful for obtaining data-driven CA and evaluating the factors that influence and predict data collection. Therefore, this could be useful to improve the accuracy of analysis and inferences based on registry data.

Canine models of human cancer: Bridging the gap to improve precision medicine

Dogs are remarkable, adaptable, and dependable creatures that have evolved alongside humans while contributing tremendously to our survival. Our canine companions share many similarities to human disease, particularly cancer. With the advancement of next-generation sequencing technology, we are beginning to unravel the complexity of cancer and the vast intra- and intertumoral heterogeneity that makes treatment difficult. Consequently, precision medicine has emerged as a therapeutic approach to improve patient survival by evaluating and classifying an individual tumor's molecular profile. Many canine and human cancers share striking similarities in terms of genotypic, phenotypic, clinical, and histological presentations. Dogs are superior to rodent models of cancer because they are a naturally heterogeneous population in which tumors occur spontaneously, are exposed to similar environmental conditions, and show more similarities in key modulators of tumorigenesis and clinical response, including the immune system, drug metabolism, and gut microbiome. In this chapter, we will explore various canine models of human cancers and emphasize the dog's critical role in advancing precision medicine and improving the survival of both man and man's best friend.

Lifetime prevalence of malignant and benign tumors in companion dogs: cross‐sectional analysis of Dog Aging Project (DAP) baseline survey

Although cancer is widely regarded as a major contributor to canine morbidity and mortality, its frequency in companion dogs has only infrequently been characterised. We analysed cross-sectional data from the baseline survey of owners of 27 541 living companion dogs enrolled in the Dog Aging Project as of 31 December 2020 to estimate the lifetime prevalence of malignant and benign tumours and several potentially-associated characteristics. Survey questions elicited information on history of 'cancer or tumors' including organ site and histologic type. Owners reported 819 malignant tumours (56% sited in the skin, muscle or other soft tissue) and 404 benign tumours (69% sited in the skin, muscle or other soft tissue). The lifetime prevalence of malignant tumours (29.7/1000 dogs) was approximately double the lifetime prevalence of benign tumours (14.7/1000 dogs). Lifetime prevalence of both malignant and benign tumours increased with dog age at survey completion. There were no statistically discernable differences in age-adjusted lifetime prevalence of malignant (prevalence ratio (PR) = 0.93 [95% confidence interval (CI) 0.82, 1.07] or benign tumours (PR = 1.10, 95% CI 0.91, 1.34) in mixed vs. purebred dogs. The lifetime prevalence of malignant tumours increased with increasing dog size class; compared to toy and small dogs, the age-adjusted PRs (95% CIs) for medium, standard, large, and giant dogs were 1.65 (1.28, 2.11), 2.92 (2.35, 3.64), 3.67 (2.92, 4.62) and 2.99 (1.23, 4.02), respectively. Similar though less pronounced patterns in relation to dog size class were observed for benign tumours. Ongoing prospective data collection will permit future studies on risk factors for canine tumour incidence.

Cross Species Analysis and Comparison of Tumors in Dogs and Cats, by Age, Sex, Topography and Main Morphologies. Data from Vet-OncoNet

The animal cancer burden is essential for the translational value of companion animals in comparative oncology. The present work aims to describe, analyze, and compare frequencies and associations of tumors in dogs and cats based on the Animal Cancer Registry created by Vet-OncoNet. With 9079 registries, regarding 2019 and 2020, 81% (n = 7355) belonged to dogs. In comparison, cats have a general one-year right advance in the mean age of cancer diagnosis compared to dogs. The multivariate topography group analysis shows a distinct pattern between the two species: dogs have higher odds of cancer in the genito-urinary system, spleen, soft tissue tumors and skin, while cats show higher odds for tumors in the eyes, digestive organs, nasal cavity, lymph nodes, bones and mammary glands. Regarding morphologies, dogs are overrepresented in mast cell tumors (MCT), melanomas, and hemangiosarcomas. While cats are overrepresented in fibrosarcomas, lymphomas (T and B-cell), in malignant mammary tumors, and squamous cell carcinoma (SCC). Females have greater odds only in the mammary gland, with males having greater odds in six of twelve topographies. This study is the first outcome of continuous animal cancer registration studies in Portugal.

Vet-ICD-O-Canine-1, a System for Coding Canine Neoplasms Based on the Human ICD-O-3.2

Cancer registries are fundamental tools for collecting epidemiological cancer data and developing cancer prevention and control strategies. While cancer registration is common in the human medical field, many attempts to develop animal cancer registries have been launched over time, but most have been discontinued. A pivotal aspect of cancer registration is the availability of cancer coding systems, as provided by the International Classification of Diseases for Oncology (ICD-O). Within the Global Initiative for Veterinary Cancer Surveillance (GIVCS), established to foster and coordinate animal cancer registration worldwide, a group of veterinary pathologists and epidemiologists developed a comparative coding system for canine neoplasms. Vet-ICD-O-canine-1 is compatible with the human ICD-O-3.2 and is consistent with the currently recognized classification schemes for canine tumors. It comprises 335 topography codes and 534 morphology codes. The same code as in ICD-O-3.2 was used for the majority of canine tumors showing a high level of similarity to their human counterparts (n = 408). De novo codes (n = 152) were created for specific canine tumor entities (n = 126) and topographic sites (n = 26). The Vet-ICD-O-canine-1 coding system represents a user-friendly, easily accessible, and comprehensive resource for developing a canine cancer registration system that will enable studies within the One Health space.

Increased risk of cancer in dogs and humans: a consequence of recent extension of lifespan beyond evolutionarily-determined limitations?

Cancer is among the most common causes of death for dogs (and cats) and humans in the developed world, even though it is uncommon in wildlife and other domestic animals. We provide a rationale for this observation based on recent advances in our understanding of the evolutionary basis of cancer. Over the course of evolutionary time, species have acquired and fine-tuned adaptive cancer protective mechanisms that are intrinsically related to their energy demands, reproductive strategies, and expected lifespan. These cancer protective mechanisms are general across species and/or specific to each species and their niche, and they do not seem to be limited in diversity. The evolutionarily acquired cancer-free longevity that defines a species' life history can explain why the relative cancer risk, rate, and incidence are largely similar across most species in the animal kingdom despite differences in body size and life expectancy. The molecular, cellular, and metabolic events that promote malignant transformation and cancerous growth can overcome these adaptive, species-specific protective mechanisms in a small proportion of individuals, while independently, some individuals in the population might achieve exceptional longevity. In dogs and humans, recent dramatic alterations in healthcare and social structures have allowed increasing numbers of individuals in both species to far exceed their species-adapted longevities (by 2-4 times) without allowing the time necessary for compensatory natural selection. In other words, the cancer protective mechanisms that restrain risk at comparable levels to other species for their adapted lifespan are incapable of providing cancer protection over this recent, drastic and widespread increase in longevity.

Age of sexual maturity and factors associated with neutering dogs in the UK and the Republic of Ireland

BACKGROUND

Surgical neutering of dogs is common, however the average age that dogs reach sexual maturity, are neutered, and dog owners' attitudes to neutering in the UK and the Republic of Ireland have not been explored in a longitudinal study.

METHODS

Owner-reported data on the timing of the first oestrus, timing of neutering and the reasons given for neutering dogs by 12 and 15 months of age were summarised. Factors associated with neutering at 15 months and factors associated with intention to neuter were quantified using multivariable logistic regression.

RESULTS

At 15 months of age, 90.0% (n = 207/230) of unneutered females had had their first oestrus. By 7, 9, 12 and 15 months of age, 22.1% (n = 131/593), 32.2% (197/593), 45.4% (n = 269/593) and 59.9% (n = 352/593) of dogs were neutered, respectively. Breed purity, dog's source, owners' intentions to neuter and the number of dogs in the household were associated with neuter status at age 15 months. Dog's sex, Kennel Club registration, dog's source, dogs intended to be working dogs and previous dog ownership were associated with intentions to neuter. Preventing puppies was the most common reason for neutering.

CONCLUSION

Understanding factors that shape owners' intentions to neuter can inform owner-vet discussions regarding whether to neuter a dog and the optimal age for doing so.

Ovariectomy reduces the risk of tumour development and influences the histologic continuum in canine mammary tumours

Influence of neutering on canine mammary tumorigenesis has been a source of vivid discussion over the last decades. The purpose of this retrospective study was to describe the association between neuter status, tumour size and degree of malignancy in a large population of 625 female dogs with altogether 1459 removed mammary tumours (MTs). MT-bearing dogs were predominantly intact (80.3%) and intact dogs were overrepresented in the tumour population compared to the control group of >19 000 females (p < .0001). Multiple MT occurred in 340 patients (54.4%) and were significantly more common in intact dogs (57.8% vs. 40.7% spayed). Neutered dogs were not only significantly more likely to have a malignant MT (p < .0001) but were significantly more often affected by more aggressive tumour subtypes (p < .0001). Positive correlation between increasing tumour size and increasingly malignant phenotype was slightly stronger in spayed (r_s  = .217; p = .021) compared to intact (r_s  = .179; p = .0003) patients. After ovariectomy, progression from benign to malignant occurs in smaller size tumours, as MT ≥2 cm in diameter were malignant in 86.9% of the spayed patients, compared to 62.0% in intact patients (p = .0002). Intact bitches have a higher risk for MTs and tumour multiplicity. MTs in neutered females are more often malignant and belong to more aggressive subtypes compared to MTs in intact dogs. In neutered bitches, histologic progression from benign to malignant and further along the cancer progression continuum occurs at smaller tumour sizes.

A text-mining based analysis of 100,000 tumours affecting dogs and cats in the United Kingdom

Cancer is a major reason for veterinary consultation, especially in companion animals. Cancer surveillance plays a key role in prevention but opportunities for such surveillance in companion animals are limited by the lack of suitable veterinary population health infrastructures. In this paper we describe a pathology-based animal tumour registry (PTR) developed within the Small Animal Veterinary Surveillance Network (SAVSNET) built from electronic pathology records (EPR) submitted to this network. From an original collection of 180232 free text (non-structured) EPRs reported between April 2018 and June 2019, we used specific text-mining methodologies to identify 109895 neoplasias. These data were normalized to describe both the tumour (type and location) and the animal (breed, neutering status and veterinary practice postcode). The resulting PTR, the largest of its kind for companion animals to date, is an important research resource being able to facilitate a wide array of research in areas including surveillance, clinical decision making and comparative cancer biology.

Measurement(s)	tumour
Technology Type(s)	digital curation • text mining
Factor Type(s)	animal species • breed • sex • neuter status
Sample Characteristic - Organism	Canis lupus familiaris • Felis catus
Sample Characteristic - Location	United Kingdom

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.15074079

Heritability and genetic variance estimation of Osteosarcoma (OSA) in Irish Wolfhound, using deep pedigree information

Background

Osteosarcoma (OSA) is a devastating disease that is common in the Irish Wolfhound breed. The aim of this study was to use a pedigree-based approach to determine the heritability of OSA in the Irish Wolfhound using data from a large publically available database.

Results

The pedigree used for this study included 5110 pure-bred Irish Wolfhounds, including 332 dogs diagnosed with OSA and 360 control dogs; dogs were considered controls if they lived over 10 years of age and were not reported to have developed OSA. The estimated heritability of OSA in the Irish Wolfhound was 0.65.

Conclusion

The results of this study indicate that OSA in the Irish Wolfhound is highly heritable, and support the need for future research investigating associated genetic mutations.

Osteosarcoma is a devastating condition that is prevalent in the Irish Wolfhound breed. In this study, our aim was to estimate heritability of osteosarcoma in the Irish Wolfhound breed. We undertook a pedigree-based analysis to estimate heritability of osteosarcoma in the Irish Wolfhound. The pedigree used included 5110 pure-bred Irish Wolfhounds, including 332 dogs diagnosed with osteosarcoma and 360 control dogs. We considered dogs to be controls if they were over 10 years of age and were not reported to have developed osteosarcoma. This study found the heritability estimate of osteosarcoma in the Irish Wolfhound to be 0.65. This score means that osteosarcoma in this breed is: 1) highly heritable and 2) a complex trait, which means that both environmental and genetic factors influence disease risk. Overall, our results provide support for further investigation into the genetic variants involved in the development of osteosarcoma in Irish Wolfhounds.

Prevalence of Reproductive Disorders including Mammary Tumors and Associated Mortality in Female Dogs

Female dogs, especially intact or neutered lately, are at increased risk for reproductive disorders including mammary tumors (MTs). This retrospective study evaluated the prevalence of reproductive pathology and associated mortality in a cohort of female dogs presented at a single veterinary clinic. The medical records of female dogs born in 2000–2003 were reviewed. The study included 599 cases, of which 293 were followed up until death. Causes of death were analyzed according to the spaying status. Among the 599 female dogs, 306 were intact (51%), 50 (8%) had been spayed before 2 years of age (ES, early spaying), and 243 (41%) after 2 years (LS, late spaying). During their lifetime, 79 dogs (13.2%) developed pyometra, and 160 (26.7%) a mammary tumor. Among the 293 dogs with complete follow-up, 103 (35.1%) had at least one MT during their lifetime, of which 53 (51.5%) died of their mammary cancer. Spayed (ES + LS) female dogs had a 4-fold decreased risk of dying from mammary cancer (OR = 0.23, 95% CI 0.11–0.47, p < 0.0001) compared to intact females. In this low-sterilization rate population, MTs developed in 35.1% of female dogs over their lifetime and was the cause of death in half of them.

Digital Lesions in Dogs: A Statistical Breed Analysis of 2912 Cases

Breed predispositions to canine digital neoplasms are well known. However, there is currently no statistical analysis identifying the least affected breeds. To this end, 2912 canine amputated digits submitted from 2014–2019 to the Laboklin GmbH & Co. KG for routine diagnostics were statistically analyzed. The study population consisted of 155 different breeds (most common: 634 Mongrels, 411 Schnauzers, 197 Labrador Retrievers, 93 Golden Retrievers). Non-neoplastic processes were present in 1246 (43%), tumor-like lesions in 138 (5%), and neoplasms in 1528 cases (52%). Benign tumors (n = 335) were characterized by 217 subungual keratoacanthomas, 36 histiocytomas, 35 plasmacytomas, 16 papillomas, 12 melanocytomas, 9 sebaceous gland tumors, 6 lipomas, and 4 bone tumors. Malignant neoplasms (n = 1193) included 758 squamous cell carcinomas (SCC), 196 malignant melanomas (MM), 76 soft tissue sarcomas, 52 mast cell tumors, 37 non-specified sarcomas, 29 anaplastic neoplasms, 24 carcinomas, 20 bone tumors, and 1 histiocytic sarcoma. Predisposed breeds for SCC included the Schnauzer (log OR = 2.61), Briard (log OR = 1.78), Rottweiler (log OR = 1.54), Poodle (log OR = 1.40), and Dachshund (log OR = 1.30). Jack Russell Terriers (log OR = −2.95) were significantly less affected by SCC than Mongrels. Acral MM were significantly more frequent in Rottweilers (log OR = 1.88) and Labrador Retrievers (log OR = 1.09). In contrast, Dachshunds (log OR = −2.17), Jack Russell Terriers (log OR = −1.88), and Rhodesian Ridgebacks (log OR = −1.88) were rarely affected. This contrasted with the well-known predisposition of Dachshunds and Rhodesian Ridgebacks to oral and cutaneous melanocytic neoplasms. Further studies are needed to explain the underlying reasons for breed predisposition or “resistance” to the development of specific acral tumors and/or other sites.

Focused ultrasound tumour ablation in small animal oncology

The cancer incidence rates for humans and animals remain high, and efforts to improve cancer treatment are crucial. Cancer treatment for solid tumours includes both treatment of the primary tumour and of metastasis. Surgery is commonly employed to resect primary and metastatic tumours, but is invasive, and is not always the optimal treatment modality. Prevention and treatment of metastatic disease often utilizes a multimodal approach, but metastasis remains a major cause of death for both human and veterinary cancer patients. Focused ultrasound (FUS) tumour ablation techniques represent a novel non-invasive approach to treating cancer. FUS ablation is precise, thus sparing adjacent critical structures while ablating the tumour. FUS ablation can occur in a thermal or non-thermal fashion. Thermal FUS ablation, also known as high intensity focused ultrasound (HIFU) ablation, destroys tumour cells via heat, whereas non-thermal FUS, known as histotripsy, ablates tumour cells via mechanical disintegration of tissue. Not only can HIFU and histotripsy ablate tumours, they also demonstrate potential to upregulate the host immune system towards an anti-tumour response. The aim of this report is provide a description of HIFU and histotripsy tumour ablation, with a focus on the basic principles of their ablation mechanisms and their clinical applicability in the field of veterinary oncology.

Translational oncotargets for immunotherapy: From pet dogs to humans

Preclinical studies in rodent models have been a pivotal role in human clinical research, but many of them fail in the translational process. Spontaneous tumors in pet dogs have the potential to bridge the gap between preclinical models and human clinical trials. Their natural occurrence in an immunocompetent system overcome the limitations of preclinical rodent models. Due to its reasonable cellular, molecular, and genetic homology to humans, the pet dog represents a valuable model to accelerate the translation of preclinical studies to clinical trials in humans, actually with benefits for both species. Moreover, their unique genetic features of breeding and breed-related mutations have contributed to assess and optimize therapeutics in individuals with different genetic backgrounds. This review aims to outline four main immunotherapy approaches - cancer vaccines, adaptive T-cell transfer, antibodies, and cytokines -, under research in veterinary medicine and how they can serve the clinical application crosstalk with humans.

Evaluation of the Proliferative Activity of Diffuse Large B-Cell Lymphoma (DLBCL) in Dogs with Respect to Patient Eligibility for Anthracycline-Based Chemotherapy

Simple Summary

Canine lymphomas usually have aggressive behavior, but respond well to chemotherapy. Despite proper diagnosis and numerous available therapeutic regimens, it is difficult to determine the prognosis and choose the optimal method of treatment in each individual patient. Diffuse large B-cell lymphoma is the most commonly diagnosed histological subtype of canine lymphoma and is treated with anthracyclines alone or in combination with other chemotherapeutics. A new diagnostic marker of prognostic and predictive value is topoisomerase IIα, which also constitutes a molecular target for anti-cancer drugs belonging to the group of topoisomerase IIα inhibitors including anthracyclines. Proliferative activity was estimated in samples of enlarged lymph nodes in dogs with diffuse large B-cell lymphoma based on mitotic count and immunohistochemical evaluation of topoisomerase IIα and Ki67 antigen expression with a view to qualifying patients for anthracycline-base chemotherapy. It has been shown that higher levels of topoisomerase IIα expression corresponded to a higher mitotic count but not to Ki67 index. These results indicate that an immunohistochemical evaluation of topoisomerase IIα expression can be used to develop a diagnostic-clinical protocol for the treatment of dogs with diffuse large B-cell lymphoma using anthracycline-based chemotherapy.

Abstract

Different types of canine lymphoma respond differently to chemotherapy and have different prognoses. Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in dogs. Topoisomerase II alpha (TOPIIα) protein has been shown to be a proliferation marker associated with prognostic significance. The aim of the study was to determine the relationship between TOPIIα expression, mitotic count (MC), and Ki67 antigen index in DLBCL in dogs, taking into account the applicability of these parameters to select the chemotherapy protocol with emphasis on the use of anthracycline drugs. Samples of formalin-fixed paraffin-embedded lymph nodes from 34 dogs with DLBCL were immunohistochemically labelled with anti-TOPIIα and Ki67. The number of positive cells and the intensity of the reaction were taken into account in order to assess TOPIIα expression. MC was estimated in the hematoxylin and eosin-stained slides in the area of 2.37 mm². Positive association between TOPIIα and MC, but no association between TOPIIα and Ki67 was found. It can be concluded that the immunohistochemical determination of TOPIIα as a molecular target for drugs from the anthracycline group may be used in association with MC to establish a diagnostic-clinical protocol for selecting dogs with DLBCL for treatment with anthracycline drugs.

The Physiological Conundrum That is the Domestic Dog

Across Mammalia, body size and lifespan are positively correlated. However, in domestic dogs, the opposite is true: small dogs have longer lives compared with large dogs. Here, I present literature-based data on life-history traits that may affect dog lifespan, including adaptations at the whole-organism, and organ-level. Then, I compare those same traits to wild canids. Because oxidative stress is a byproduct of aerobic metabolism, I also present data on oxidative stress in dogs that suggests that small breed dogs accumulate significantly more circulating lipid peroxidation damage compared with large breed dogs, in opposition to lifespan predictions. Further, wild canids have increased antioxidant concentrations compared with domestic dogs, which may aid in explaining why wild canids have longer lifespans than similar-sized domestic dogs. At the cellular level, I describe mechanisms that differ across size classes of dogs, including increases in aerobic metabolism with age, and increases in glycolytic metabolic rates in large breed dogs across their lifespan. To address potential interventions to extend lifespan in domestic dogs, I describe experimental alterations to cellular architecture to test the "membrane pacemaker" hypotheses of metabolism and aging. This hypothesis suggests that increased lipid unsaturation and polyunsaturated fatty acids in cell membranes can increase cellular metabolic rates and oxidative damage, leading to potential decreased longevity. I also discuss cellular metabolic changes of primary fibroblast cells isolated from domestic dogs as they are treated with commercially available drugs that are linked to lifespan and health span expansion.

Age- and breed-matched retrospective cohort study of malignancies and benign skin masses in 660 dogs with allergic dermatitis treated long-term with versus without oclacitinib

OBJECTIVE

To compare the cumulative incidences of malignancies and benign skin masses and the mean age at death or euthanasia in dogs with allergic dermatitis treated long-term with versus without oclacitinib.

ANIMALS

660 client-owned dogs.

PROCEDURES

Medical records were searched to identify dogs with allergic dermatitis treated for ≥ 6 months with oclacitinib (exposed dogs; n = 339) versus other available treatments before the introduction of oclacitinib (nonexposed dogs; 321) and with ≥ 24 months of follow-up information available. Nonexposed dogs were age and breed matched with 321 of the exposed dogs; data for the remained 18 exposed dogs were included in statistical analyses. Results for cumulative incidences of malignancies and other variables were compared between groups, and the effect of daily maintenance dosage of oclacitinib on cumulative incidences of malignancies and other skin masses was evaluated within the exposed group.

RESULTS

No meaningful differences were detected in the cumulative incidences of malignancies and overall skin masses or the mean age at death or euthanasia for dogs in the exposed group (16.5% [56/339], 56.6% [192/339], and 11.2 years [n = 80], respectively) versus the nonexposed group (12.8% [41/321], 58.3% [187/321], and 11.8 years [71], respectively). There was no association identified between daily maintenance dosage of oclacitinib and odds of malignancy or benign skin masses for dogs in the exposed group.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that long-term treatment with oclacitinib did not pose additional risk for malignancy in dogs; however, veterinarians should continue to observe FDA-approved label warning and precaution statements for oclacitinib and regularly screen for neoplasia in dogs with allergic skin disease treated with or without oclacitinib.

Comprehensive live-cell imaging analysis of cryptotanshinone and synergistic drug-screening effects in various human and canine cancer cell lines

Background

Several studies have highlighted both the extreme anticancer effects of Cryptotanshinone (CT), a Stat3 crippling component from Salvia miltiorrhiza, as well as other STAT3 inhibitors to fight cancer.

Methods

Data presented in this experiment incorporates 2 years of in vitro studies applying a comprehensive live-cell drug-screening analysis of human and canine cancer cells exposed to CT at 20 μM concentration, as well as to other drug combinations. As previously observed in other studies, dogs are natural cancer models, given to their similarity in cancer genetics, epidemiology and disease progression compared to humans.

Results

Results obtained from several types of human and canine cancer cells exposed to CT and varied drug combinations, verified CT efficacy at combating cancer by achieving an extremely high percentage of apoptosis within 24 hours of drug exposure.

Conclusions

CT anticancer efficacy in various human and canine cancer cell lines denotes its ability to interact across different biological processes and cancer regulatory cell networks, driving inhibition of cancer cell survival.

Gonadotropin-Releasing Hormone (GnRH) Agonist Implants for Male Dog Fertility Suppression: A Review of Mode of Action, Efficacy, Safety, and Uses

At present, only surgical sterilization is available for veterinarians and pet owners seeking suppression of fertility in male dogs, in most countries. An alternative contraceptive alternative approach is GnRH releasing implants that desensitize the pituitary to the stimulatory effects of GnRH and thereby block testicular function (testosterone and sperm production). Two GnRH agonists (deslorelin and azagly-nafarelin) have been researched in controlled release formulations for this purpose. A deslorelin-releasing biodegradable implant, marketed under the name Suprelorin®, has been available in Australia and New Zealand since 2007, the European Union (EU) since 2008, and received regulatory approval in China and Mexico in late 2019. Two versions of the implant are available, one labeled for a minimum of 6 months of fertility suppression in male dogs, and the other for a minimum of 12 months in male dogs. Another GnRH agonist (azagly-nafarelin) was also included in a solid implant (Gonazon®). Research results showed it delivered 6-months to 1 year of suppressed fertility; however, it is not commercialized. This review paper summarizes research on the mechanism of action for these technologies and compiles and interprets the research on efficacy and safety. New findings on usage of the deslorelin releasing implant in countries where veterinarians and pet owners have this option is shared. Research on off-label use of the product in male dogs is also reviewed. This review aims to aid in the evaluation of the deslorelin releasing implant as an adjunct or alternative for surgical sterilization of male dogs.

Evaluation of intrinsic and extrinsic risk factors for dog visceral hemangiosarcoma: A retrospective case-control study register-based in Lazio region, Italy

The genetic and breed susceptibility of visceral hemangiosarcoma in dogs has been studied, but there is no evidence of environmental risk factors as reported in human medicine. We conducted a case-control study in which the sampling population was the list of canine oncology cases of the Animal Tumour Registry of Lazio region, Italy (2009-2017). We defined cases as dogs with visceral hemangiosarcoma and controls as dogs affected by another neoplasm. The ratio between controls and cases was 3:1. Analysed variables were: age, weight, sex, reproductive status, size, breed, nutrition habit, living environment and location of the house. We performed a preliminary univariate analysis to select potential risk factors (p-value < 0.2) then entered in a forward stepwise logistic regression model. Ninety-three cases enrolled in the study were compared with 279 controls. The multivariable logistic regression identified age, reproductive status and breed as significant risk factors. Results showed an increasing risk with increasing age for age classes 6-10 and > 10 years old (OR = 9.69, 95 % CI: 1.21-77.62; OR = 14.01, 95 % CI: 1.65-119.03). Neutered animals (male and female) were at greater risk compared to intact ones. The breeds at greatest risk were German shepherd (OR = 4.17, 95 % CI: 1.25-13.86) and mixed breed (OR = 3.50, 95 % CI: 1.44-8.51). The last finding could be explained by the genetic origin of the animals, which may include German shepherd or another possible breed at risk. No other individual or environmental variables were identified as risk factors. The findings of this work indicate that genetic predisposition is the key element in visceral hemangiosarcoma development.

A modern look at the molecular-biological mechanisms of breast tumours in dogs

High morbidity and increase in the number of registrations of breast tumours in dogs, their wide application as biological models, discussion of numerous questions of oncogenesis, and the lack of a uniform/unified methodological approach to the study of molecular and biological mechanisms of treatment of cancer determine the relevance of the problem of cancer both in humans and in our domestic companions. The analysis of publications allowed us to establish the following patterns of carcinogenesis. The peculiarities of the biological behaviour of breast tumours depend on their pathomorphological structure. Genetic predisposition to breast cancer is characteristic only in the single breed aspect. Environmental factors are of critical relevance to carcinogenesis : chemical pollutants initiate oncogenesis indirectly – by altering the expression of several receptors, impaired endocrine balance and direct mutagenic effects. Reproductive status plays a key role in the initiation and progression of breast tumours by reducing the expression of estrogen, progesterone and prolactin receptor genes. The inflammatory response that accompanies the neoplasia process is characterized by increased production of cytokines, cyclooxygenase-2, interleukins (IL-1, IL-6, IL-8), vascular endothelial growth receptors, and impaired hemostatic status (oxidative stress), which promotes progression of disease. In breast cancer in dogs, genomic instability leads to genomic aberrations, and subsequently, mutations that support the proliferation, survival and dissemination of neoplastic cells. The initiation and progression of mammary gland tumours is provided by cancer stem cells by disrupting the regulation of precursor cell self-renewal, which also predispose to resistance to chemotherapeutic agents, radiation, and hormonal cancer therapy. The analysis of the publications revealed the major markers of carcinogenesis that could potentially be used as biological targets for the design of modern diagnostic strategies and high-performance therapeutic protocols.