Aetiology and diagnosis of persistent nasal disease in the dog: a retrospective study of 42 cases

Comparison of culture-dependent and -independent bacterial detection results on nasal swabs in dogs with nasal discharge

OBJECTIVES

The role of bacterial communities in the pathophysiology of canine nasal disease is still unclear. How and when to treat dogs with suspected secondary bacterial rhinitis and on which test to rely before making a decision to treat with antimicrobials has not been established. The objective is to compare the results of bacterial identification using agar-plate cultures and 16S rRNA gene amplicon sequencing in dogs with nasal discharge suspected to be of bacterial origin.

MATERIALS AND METHODS

Twenty-nine client-owned dogs presented for investigation of nasal disease were included in the study. Paired swabs were collected from the same affected nasal cavity. One swab was streaked on 4 agar media (Columbia Blood Agar, MacConkey, Chapman and Edward's). The other swab was stored in a sterile cryotube at -80°. Extracted DNA underwent a polymerase chain reaction targeting the V1-V3 region of the 16S rRNA gene.

RESULTS

At least one of the species detected by amplicon sequencing with a relative abundance of >10% was also identified by culture in 14 cases (48.3%), in association with marked predominance of one taxon (>80% relative abundance) in six of 14 cases. In 12 dogs (41.4%), the cultured isolates were rare or undetected components of the corresponding sequence libraries. A negative culture in the face of bacterial predominance (>50% relative abundance) of a potentially pathogenic bacteria detected by sequencing occurred in 17% (n=5) of cases; however, the use of other agar media may have decreased this percentage.

CLINICAL SIGNIFICANCE

Standard culture does not reliably predict the bacterial profile detected by 16S rRNA gene amplicon sequencing.

Advantages of the co2 laser use in the rare condition of nasal mucosa squamous cell carcinoma surgery in dogs-a clinical prospective study

Nasal mucosa tumors are an uncommon process and very dificult to work on with surgery. Radiotherapy associated or not with chemotherapy is the standard method to treat the disease. However, its access it is in the majority of the case not possible, making the surgery the best choice to try to achieve the patient's control. The anatomy of the region makes the complete surgical resection very difficult to achieve using the common and conventional blade scalpel surgery. The study features the advantages of using a CO2 laser to perform nasal mucosa carcinoma surgery in 6 dogs (N = 6). For the work we used an Aesculigth CO2 surgical laser model -Vetscalpel®, with the settings of 12Watts in a Superpulse mode, and a 0.25-0.4 mm focus to dissect the nasal mucosa, and a 1.5 mm focus for vaporization of the area. All the masses were histopathologically characterized as squamous cells carcinoma. The CO2 surgical laser allow us to work in a bloodless region promoting a more accurate dissection of the nasal mucosa sparing therefore the underlying and adjacent tissues and being less invasive. Also, it was possible to do the vaporization of the entire surgical area interviened. None of the patients presented relapse of clinical signs. Only 2 individuals were alive at the end of the study, presenting a survival rate of 420 and 514 days, which is in the same line of literature results of the treatment with radiotherapy combined with chemotherapy wich shows a median of 474-580 days. The study demonstrates successful outcomes with CO2 laser surgery in treating nasal mucosa SCC in dogs, with patients experiencing improved survival rates compared to traditional treatment methods. This highlights the efficacy and potential of CO2 laser surgery as a valuable tool in managing aggressive nasal tumors in veterinary oncology.

Diagnostic benefits of platelet-to-lymphocyte, neutrophil-to-lymphocyte, and albumin-to-globulin ratios in dogs with nasal cavity diseases

BACKGROUND

A multimodal approach for diagnostic tests under anesthesia is required to diagnose nasal cavity pathology (NP) reliably in dogs. Blood test results may provide clues to the suspected NP.

METHODS

This prospective blinded study assessed 72 dogs with chronic nasal discharge due to NPs, and 10 healthy dogs as the control group (CG). NPs were diagnosed using whole-body computed tomography (CT), upper airway endoscopy, examination of nasal mucosal swabs by bacterial and fungal culture, and histopathological examination of nasal mucosa biopsies. The exclusion criteria were the presence of any additional diseases or corticosteroid pre-treatment. In consideration of these exclusion criteria, 55 dogs entered the study. Dogs were classified into benign (benign tumors, idiopathic rhinitis (IR), and others) and malignant (carcinomas and sarcomas) NP groups. Blood count and blood chemistry tests were performed. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and albumin-to-globulin ratio (AGR) were calculated and compared.

RESULTS

25 dogs with malignant NP (13 and 12 with carcinomas and sarcomas, respectively) and 30 dogs with benign NP (seven with benign tumors,13 with IR, and 10 others) were included. In general, in dogs with NP there were only slight abnormalities in complete blood count. However, PLR was significantly higher in dogs with malignant NP (carcinoma and sarcoma) than in those with benign NP and in the CG. Compared with the CG, the NLR was significantly increased in all dogs with NP, and the AGR was mild but significantly lower, except in dogs with sarcomas and benign tumors.

CONCLUSIONS

In dogs with nasal disease alone, there are usually no marked abnormalities in blood count. However, while mildly increased NLR and decreased AGR can be observed in almost all NPs, an increased PLR may indicate a malignant NP and can be used as an additional screening tool in dogs with nasal discharge due to nasal cavity pathology.

Construction of diagnostic prediction model for canine nasal diseases using less invasive examinations without anesthesia

Advanced imaging techniques under general anesthesia are frequently employed to achieve a definitive diagnosis of canine nasal diseases. However, these examinations may not be performed immediately in all cases. This study aimed to construct prediction models for canine nasal diseases using less-invasive examinations such as clinical signs and radiography. Dogs diagnosed with nasal disease between 2010 and 2020 were retrospectively investigated to construct a prediction model (Group M; GM), and dogs diagnosed between 2020 and 2021 were prospectively investigated to validate the efficacy (Group V; GV). Prediction models were created using two methods: manual (Model 1) and LASSO logistic regression analysis (Model 2). In total, 103 and 86 dogs were included in GM and GV, respectively. In Model 1, the sensitivity and specificity of neoplasia (NP) and sino-nasal aspergillosis (SNA) were 0.88 and 0.81 in GM and 0.92 and 0.78 in GV, respectively. Those of non-infectious rhinitis (NIR) and rhinitis secondary to dental disease (DD) were 0.78 and 0.88 in GM and 0.64 and 0.80 in GV, respectively. In Model 2, the sensitivity and specificity of NP and SNA were 0.93 and 1 in GM and 0.93 and 0.75 in GV, respectively. Those of NIR and DD were 0.96 and 0.89 in GM and 0.80 and 0.79 in GV, respectively. This study suggest that it is possible to create a prediction model using less-invasive examinations. Utilizing these predictive models may lead to appropriate general anesthesia examinations and treatment referrals.

Intranasal and Serum Gentamicin Concentration: Comparison of Three Topical Administration Protocols in Dogs

Antimicrobials' topical administration efficacy has not been assessed in dogs with upper respiratory tract disease. The aim was to compare the concentration of gentamicin in nasal lavage fluid (NALF) and in serum after three topical protocols. This was a prospective crossover study of ten healthy dogs. Gentamicin was nebulized for a duration of 1 week, twice a day, for 10 min in the first protocol (10-min protocol) and for 3 min in the second protocol (3-min protocol), while the third protocol consisted of the administration of 0.25 mL of gentamicin in each nostril (drop protocol). Median concentrations of gentamicin in NALF were 9.39 µg/mL (8.12-19.97 interquartile range), 4.96 µg/mL (4.60-6.43) and 137.00 µg/mL (110.5-162.00) in the 10-min protocol, 3-min protocol and drop protocol, respectively. The result for the drop protocol was significantly higher than those of both nebulization protocols in NALF (p = 0.039). In serum, the gentamicin concentration was 0.98 µg/mL (0.65-1.53) and 0.25 µg/mL (0.25-0.44) in the 10-min and 3-min protocols, respectively. Gentamicin was not detected in the serum of seven out of ten dogs in the drop protocol, and gentamicin was significantly higher in the 10-min protocol compared to the drop protocol (p = 0.001). This study found that the 10-min, 3-min and drop protocols achieved superior concentrations in NALF compared to the minimum inhibitory concentration for gentamicin-sensitive bacteria, while remaining below the toxic values in blood.

Osteomyelitis caused by Aspergillus terreus complex in a dog: a case report

BACKGROUND

In dogs, the most frequently reported mycosis associated with Aspergillus spp. are respiratory infections. Systemic aspergillosis is uncommon, with reported cases been associated with several Aspergillus species. Aspergillus terreus species complex are ubiquitous organisms, unfrequently associated with local or systemic disease in animals and humans, and treatment of osteomyelitis caused by this species is usually unfavorable.

CASE PRESENTATION

This case report describes the case of a 5-year-old dog, referred to the Veterinary Hospital of the Faculty of Veterinary Medicine of the University of Lisbon, Portugal, with a history of lameness of the right thoracic limb. Radiographs and CT scan revealed two different lesions on right humerus and radio, which were biopsied. The samples collected were submitted to cytological and histopathological evaluation and bacterial and mycological culture. Environmental samples, including of the surgery room and of the biopsy needle were also evaluated for the presence of fungi. Regarding biopsy samples, bacterial culture was negative, but mycological analysis originated a pure culture of a fungal species later identified as Aspergillus terreus by Sanger sequencing. Results were compatible with histopathologic examination, which revealed periosteal reaction and invasion of hyphae elements. Also, mycological analysis of both environmental samples evaluated were negative. The virulence profile of the fungal isolate was phenotypically characterized using specific media, allowing to reveal its ability to produce several enzymes involved in its pathogenicity, namely lipase, hemolysin and DNAse, corresponding to a Virulence Index (V. Index.) of 0.43. The patient was submitted to itraconazole therapy for 8 weeks. After 3 weeks, the patient showed significant clinical improvement, and after 6 weeks no radiographic signs were observed.

CONCLUSIONS

Antifungal therapy with itraconazole can contribute to the remission of canine infections promoted by Aspergillus terreus complex with a relevant V. Index.

Retrospective study of 1050 dogs with respiratory symptoms in Japan (2005-2020)

BACKGROUND

Few studies have investigated the incidence of respiratory diseases based on anatomical sites or the relationship between breed and these diseases.

OBJECTIVE

The objective of this study was to investigate the prevalence of canine respiratory diseases among dogs in Japan, with relationship to the breed.

METHODS

We retrospectively reviewed the medical records of dogs with respiratory symptoms and calculated the odds ratio (OR) to evaluate the relationship between breed and disease.

RESULTS

A total of 1050 dogs with respiratory symptoms were included in this study. Miniature dachshunds were the most common breed affected by respiratory diseases. Among tracheobronchial diseases, there was a significant association between some small breeds and tracheobronchial collapse, miniature dachshunds (OR: 4.44, 8.43, 95% confidence interval [CI]: 3.17-6.22, 4.33-16.0) and chronic bronchitis and bronchiectasis. Among nasal diseases, miniature dachshunds (OR: 27.2, 95% CI: 16.8-44.8) and golden retrievers (OR: 21.0, 95% CI: 6.43-69.3) were the most affected by non-infectious rhinitis and nasal aspergillosis, respectively. Brachycephalic obstructive airway syndrome was the most common disease among pharyngeal and laryngeal diseases, with a relationship with breed being found in some brachycephalic breeds, and Pomeranians (OR: 2.7, 95% CI: 1.42-5.17).

CONCLUSIONS

Respiratory diseases in dogs are strongly correlated with popular breeds in Japan. Miniature dachshunds, in particular, are associated with many respiratory diseases, which may differ from international reports. Thus, this result may help in the early detection, prevention, treatment, and elucidation of the pathophysiology of canine respiratory diseases.

Utility of fungal polymerase chain reaction on nasal swab samples in the diagnosis and monitoring of sinonasal aspergillosis in dogs

Background

In dogs with sinonasal aspergillosis (SNA) the utility of PCR in the diagnosis and monitoring of the disease after treatment has not been assessed.

Objectives

To evaluate the presence of fungal DNA using quantitative PCR targeting Aspergillus fumigatus (Aspfum) and Aspergillus spp. (PanAsp), and PCR targeting multiple fungal species (PanFun), in samples obtained from nasal cavities of dogs with SNA, other nasal diseases and healthy dogs.

Animals

Sixty‐two dogs including 20 with SNA, 12 with cured SNA (of which 10 are from the SNA group), 20 dogs with Non‐SNA nasal disease, and 20 healthy dogs.

Methods

Prospective cross‐sectional study. Aspfum, PanAsp, and PanFun were performed on blindly collected nasal swabs obtained in anesthetized dogs.

Results

In SNA dogs, Aspfum and PanAsp were positive in 13/20 and 14/20 dogs. In all dogs in the 3 other groups, A. fumigatus DNA was not detected using Aspfum. PanAsp was positive in 3 non‐SNA dogs: 1 with cured SNA and 2 with Non‐SNA nasal disease. A Ct cut‐off value of 33.3 for Aspfum demonstrated 65% sensitivity and 100% specificity. A Ct cut‐off value of 34.5 for PanAsp demonstrated 70% sensitivity and 96.2% specificity. PanFun was positive in 16/20, 12/12, 19/20, and 7/20 dogs in the SNA, cured SNA, Non‐SNA, and healthy groups, respectively.

Conclusion and Clinical Importance

Aspfum and PanAsp on blindly collected nasal swabs can be useful for the detection of SNA at diagnosis and at cure, especially when more invasive methods are not available.

Diagnosis, treatment and postsurgical complications in a dog with epileptic seizures and a naso-ethmoidal meningoencephalocele

BACKGROUND

Naso-ethmoidal meningoencephalocele is usually a congenital anomaly consisting of a protrusion of cerebral tissue and meninges into the ethmoidal labyrinth. The condition is a rare cause of structural epilepsy in dogs. We report the clinical presentation, surgical intervention, postoperative complications and outcome in a dog with drug resistant epilepsy secondary to a meningoencephalocele.

CASE PRESENTATION

A 3.3-year-old male neutered Tamaskan Dog was referred for assessment of epileptic seizures secondary to a previously diagnosed left-sided naso-ethmoidal meningoencephalocele. The dog was drug resistant to medical management with phenobarbital, potassium bromide and levetiracetam. Surgical intervention was performed by a transfrontal craniotomy with resection of the meningoencephalocele and closure of the dural defect. Twenty-four hours after surgery the dog demonstrated progressive cervical hyperaesthesia caused by tension pneumocephalus and pneumorrhachis. Replacement of the fascial graft resulted in immediate resolution of the dog's neurological signs. Within 5 months after surgery the dog progressively developed sneezing and haemorrhagic nasal discharge, caused by sinonasal aspergillosis. Systemic medical management with oral itraconazole (7 mg/kg orally q12h) was well-tolerated and resulted in resolution of the clinical signs. The itraconazole was tapered with no relapsing upper airway signs. The dog's frequency of epileptic seizures was not affected by surgical resection of the meningoencephalocele. No treatment adjustments of the anti-epileptic medication have been necessary during the follow-up period of 15 months.

CONCLUSIONS

Surgical resection of the meningoencephalocele did not affect the seizure frequency of the dog. Further research on prognostic factors associated with surgical treatment of meningoencephaloceles in dogs is necessary. Careful monitoring for postsurgical complications allows prompt initiation of appropriate treatment.

Computed tomography may be helpful in discriminating grass awn foreign body rhinitis from non-foreign body rhinitis in dogs

Grass awn foreign bodies are a common cause of rhinitis in dogs.  Early detection and complete removal of these foreign bodies are important for minimizing risks of long term complications. The objective of this retrospective, descriptive cross-sectional study was to determine whether discriminating CT findings exist between dogs with grass awn foreign body rhinitis and dogs with non-foreign body rhinitis. Computed tomography scans of 47 dogs with a confirmed diagnosis of non-foreign body rhinitis (25 cases) or of a nasal grass awn foreign body (22 cases) were reviewed. In the latter group, grass seeds were visualized directly on CT images for one of 22 (5%) cases. Focal lysis was more strongly associated with the presence of a grass awn foreign body (P = .012, LR = 3.0) and widespread lysis (involving more than one-third of the nasal cavity and/or bilateral) appeared associated with non-foreign body rhinitis (P = .046, LR = 2.0). Maxillary recess filling was associated with non-foreign body rhinitis (LR = 4.4) as was widespread lysis (LR = 2.0). Findings supported prioritizing grass awn foreign body rhinitis as a differential diagnosis for dogs with the former CT characteristics, even if a grass awn cannot be directly visualized.

Rhinoscopic Appearance and Clinical Features of a Nasal Transmissible Venereal Tumor in a Dog

A 2-year-old male neutered mixed breed dog was referred for evaluation of left-sided unilateral epistaxis and mucoid discharge following adoption from Mexico 2 months prior to presentation. Computed tomography (CT) showed soft tissue that filled the entirety of the left nasal passage with mild turbinate loss. Subsequent rhinoscopy revealed multifocal patches of discrete, white, wispy, vascularized abnormal tissue in the left nasal cavity. Cytology and histopathology procured with rhinoscopic-guidance were suspicious for transmissible venereal tumor (TVT). Confirmation of a TVT diagnosis was made with polymerase chain reaction for the long interspersed element inserted upstream of the c-myc gene. The dog was treated with 4 cycles of vincristine (0.5 mg/m², IV, once every 7 days) with complete and sustained resolution of clinical signs shortly after the third cycle. Nasal TVT in dogs is an uncommon presentation of a neoplasm that primarily results in genital or oral lesions. There is a void in the veterinary literature regarding the rhinoscopic appearance, as well as limited clinical descriptions of nasal TVT. Therefore, the objectives of this report were to provide a detailed description of the rhinoscopic appearance of a canine nasal TVT, in addition to clinical features, diagnostic findings, CT imaging, and successful therapeutic management.

Nasal foreign bodies identified by rhinoscopy in dogs: 42 cases

OBJECTIVE

To evaluate signalment, clinical presentation, location and type of nasal foreign bodies identified by rhinoscopy in dogs.

MATERIALS AND METHODS

We retrospectively reviewed medical records from dogs that presented for consultation between April 2012 and June 2019 and were diagnosed with nasal foreign body via rhinoscopy.

RESULTS

Forty-two dogs met the study's inclusion criteria. Thirty (71.4%; 30/42) were purebreds. Males accounted for 59.5% (25/42) of cases. The median age was 4.0 years old and 76.2% (32/42) were dogs up to 7 years of age. Mean bodyweight was 21.8 kg and dogs weighing more than 10 kg were overrepresented (78.6%; 33/42). Sneezing occurred in 78.6% (33/42) of cases. Foreign body retrieval was achieved by rhinoscopy in all cases. The foreign body was extracted from the right nasal cavity in 52.4% (22/42) of cases and from the left one in 42.9% (18/42). Two dogs (4.8%; 2/42) presented with one foreign body in each nasal cavity. Most nasal cavity foreign bodies (90.5%; 38/42) were grass awns. Three (7.2%; 3/42) were mineral and one (1/42) was fabric. Follow-up was documented for 35 patients, of which 97.1% (34/35) experienced resolution of clinical signs. Seven cases (16.7%; 7/42) were lost to follow-up.

CLINICAL SIGNIFICANCE

Nasal foreign bodies were more common in dogs up to 7 years of age and heavier than 10 kg. Sneezing was the primary clinical sign. The vast majority of foreign bodies were grass awns and rhinoscopy was an effective means of nasal cavity foreign body retrieval.

Treatment of nasal tumours in dogs: a review

Nasal tumours are common neoplasms in dogs and often represent a diagnostic and therapeutic challenge due to their confined location within the nasal cavities. The main goal of this review is to extract the most relevant information from a wide and often confusing evidence-based medicine on the treatment of canine nasal tumours and conclude with current recommendations. This report highlights the different therapeutic modalities available and describes their technical aspects, interests and limitations. Megavoltage radiotherapy, as the most recent treatment and standard of care, is particularly examined, especially the different types of radiotherapy units, the main protocols used and their advantages and limits. Newer and non-conventional treatments are also discussed.

Upper digestive tract abnormalities in dogs with chronic idiopathic lymphoplasmacytic rhinitis

BACKGROUND

Chronic idiopathic lymphoplasmacytic rhinitis (CILPR) is a common inflammatory disorder of unknown etiology affecting the nasal cavity of dogs. The diagnosis is made by exclusion of other causes of nasal disease and specific therapeutic protocols are lacking. In human medicine, a relationship between CILPR and gastrointestinal clinical signs has been postulated, and remission of respiratory signs after clinical trials with medications for gastrointestinal disorders has been observed.

OBJECTIVES

To describe history, clinical presentation, endoscopic and histopathologic concurrent respiratory and digestive tract abnormalities, and to evaluate improvement of respiratory signs after treatment for gastrointestinal signs.

ANIMALS

Twenty-five dogs with CILPR.

METHODS

Prospective study. For inclusion, following information had to be available: respiratory and digestive clinical signs, airway and digestive tract endoscopic abnormalities, histologic evaluation of respiratory and gastrointestinal tract biopsy specimens, and clinical response to different treatment strategies.

RESULTS

Twenty-two dogs had endoscopic gastrointestinal lesions, whereas 13 dogs had concurrent gastrointestinal signs. Most esophageal and duodenal endoscopic abnormalities were classified as moderate or severe. Respiratory and gastrointestinal tract histologic evaluation identified mostly chronic inflammation. Remission or marked improvement of respiratory signs was observed in the majority of dogs treated only for gastrointestinal signs up to 12 months after endoscopy. No significant associations between treatments and follow-up information were found.

CONCLUSION AND CLINICAL IMPORTANCE

Nasal and upper digestive tract abnormalities coexist in some dogs with CILPR. Lack of standardized therapeutic protocols suggests caution when interpreting improvement in nasal clinical signs. Additional studies are needed to explore the possibility of a cause-effect relationship between the 2 processes.

CT findings in 20 dogs and six cats with confirmed nasal foreign bodies

The diagnosis and treatment of nasal foreign bodies usually includes a combination of rhinoscopy and imaging techniques, such as CT. The purpose of this retrospective, multicenter study was to describe the CT characteristics of nasal foreign bodies in dogs and cats and to determine if different nasal CT features exist between acute and chronic cases. Twenty dogs and six cats met the inclusion criteria. Eleven nasal foreign bodies (42%) were detected confidently with CT. The foreign body had a linear shape in 81% of cases and displayed a "tubular-like appearance" in 54% of cases. In five cases (19%), a foreign body was suspected but not clearly visible. Additional CT changes were present in the nasal passages in 96% of the cases. The presence of turbinate destruction (P = .021) and mucosal thickening (P = .014) on CT were associated with the presence of a chronic nasal foreign body. In this sample, the nature of the foreign body did not influence its visibility and was not associated with specific CT characteristics. Computed tomography may be useful in the investigation of nasal foreign bodies, however, a negative CT examination does not exclude their presence.

Canine Nasal Disease: An Update

Nasal disease in dogs is common and is often accompanied by chronic nasal discharge with or without other clinical signs. A thorough history and physical examination often guide the most appropriate choice of diagnostic testing to provide the best chance of attaining a diagnosis as to cause, and therefore, the most appropriate treatment. The purpose of this article is to guide the practitioner through a logical approach to the evaluation of dogs that are presented with signs of nasal disease.

Co-occurrence of Nasal Polyps and Neoplasms of the Canine Nasal Cavity

Nasal polyps in dogs are space-occupying soft-tissue masses that have been encountered concurrently with intranasal neoplasia in surgical biopsy specimens. The proportion of nasal polyp co-occurrence with primary nasal tumors was examined, and follow-up biopsies on dogs initially diagnosed with nasal polyp were reviewed. Histologic sections from 321 cases of intranasal neoplasia and 50 cases of nasal polyp from 2004 to 2017 were reviewed. Of the 321 cases of intranasal neoplasia, 51 (16%) had concurrent nasal polyps, and most of these (47/51) had intranasal carcinoma. Twenty-five of the 50 dogs with a primary diagnosis of nasal polyp were rebiopsied, and the diagnoses in these subsequent biopsies were nasal polyp in 15, malignant neoplasm in 9, and intranasal nematode in 1. Nasal polyps occurred frequently in conjunction with nasal carcinoma. In dogs with a diagnosis of nasal polyp, repeat biopsy to reveal possible neoplasia is warranted.

Scopulariopsis brevicaulis Rhinosinal Infection in a Dog

A 1 yr old castrated male American Staffordshire terrier mix was treated for Scopulariopsis brevicaulis that was discovered during an evaluation of chronic rhinosinusitis. A sinusotomy was performed, with intraoperative infusion of amikacin-impregnated gel and systemic administration of postoperative amikacin. Antibiotic therapy was initially chosen because of historic culture of Mycoplasma. Fungal culture of the frontal sinus identified S. brevicaulis by combined phenotypic characterization and DNA sequencing after morphologic analysis failed to identify the organism. Systemic terbinafine therapy was instituted after fungal culture results were available. The patient recovered well and has had no clinical relapse of disease 3 yr after treatment. This is the first reported case of a fungal rhinosinusitis caused by S. brevicaulis in a dog. Reports of Scopulariopsis infections in humans indicate that treatment of S. brevicaulis infection is hampered by multidrug resistance; prognosis may be poor in people with invasive infections and is currently unknown in dogs. Multimodal therapy, including concurrent surgical and systemic intervention, may be necessary to optimize treatment success.

Comparison of two minimally invasive enilconazole perendoscopic infusion protocols for the treatment of canine sinonasal aspergillosis

OBJECTIVES

To compare two minimally invasive enilconazole infusion protocols for the treatment of canine sinonasal aspergillosis and evaluate the importance of complete endoscopic debridement in determining first treatment success rate.

MATERIALS AND METHODS

Data for 48 dogs with confirmed sinonasal aspergillosis treated with endoscopic debridement followed by per-endoscopic enilconazole infusion were collected. Twenty-four dogs were treated according to the previously published 1-hour infusion protocol and 24 dogs underwent a simplified 15-minute infusion protocol. Completeness of debridement, evaluated as partial or complete at the end of the procedure and outcome after one or several treatments were assessed in all dogs. Multi-variable analysis was performed to derive odds ratios and 95% confidence intervals.

RESULTS

The median duration of the simplified protocol - 92∙3 minutes (range 40 to 140) - was substantially shorter than the duration of the previous protocol - 201∙3 minutes (range 120 to 265). First treatment success rates were 58 and 62∙5% for the previous and simplified protocol, respectively. Overall treatment success rate was similar in both groups (96%). Complete debridement was associated with an improved first treatment success rate compared to partial debridement.

CLINICAL SIGNIFICANCE

The simplified protocol is a valid alternative approach to the treatment of sinonasal aspergillosis. Completeness of endoscopic debridement before infusion is an important step for the success of treatment in canine sinonasal aspergillosis.

The evaluation of three treatment protocols using oral prednisone and oral meloxicam for therapy of canine idiopathic lymphoplasmacytic rhinitis: a pilot study

Background

Idiopathic lymphoplasmacytic rhinitis (LPR) is a common inflammatory disorder of the nasal cavity in dogs due to unknown etiology. It is characterised by non-specific clinical signs, including nasal discharge, epistaxis and breathing problems. Diagnosis is usually based on the histopathologic identification of infiltrating plasmocytes and lymphocytes in the nasal mucosa and the exclusion of other underlying diseases. Treatment strategies include glucocorticoids, non-steroidal anti-inflammatory drugs, antibiotics and antifungal medications. The aim of this study was to evaluate the efficacy of various therapeutic protocols for managing canine lymphoplasmacytic rhinitis based on the results of clinical, endoscopic and histological examinations, and to determine the relapse rate for LPR in dogs.

Twenty dogs of different breeds and both sexes, aged 1 to 14 years, were divided into four groups, each consisting of five dogs, including three experimental groups diagnosed with LPR and a control group.

The dogs from the first experimental group were administered prednisone orally at 1 mg/kg/day in the first 4 weeks and 0,5 mg/kg/day in the following 2 weeks. The second group of dogs was administered meloxicam orally at 0,1 mg/kg/day in the first 3 weeks, followed by prednisone at 1 mg/kg/day in the following 2 weeks and 0,5 mg/kg/day in the last week of the treatment. The dogs from the third experimental group were administered meloxicam orally at 0,1 mg/kg/day for 6 weeks. The control group of dogs was administered empty gelatin capsules (placebo) orally for 6 weeks. Clinical signs, endoscopic and histopathologic lesions were scored before and after treatment. Groups were compared using Chi- squared statistics in a 2 × 2 table for pre- versus post-treatment scores.

Results

Clinical signs persisted in the group treated with meloxicam and were mostly resolved in prednisone-treated dogs. However, endoscopic and histological changes were still observed in these two groups after treatment. The severity of all diagnostic features was reduced in the group treated with meloxicam for 3 weeks followed by prednisone for 3 weeks. The significant differences (p < 0.05) were noted between experimental and control groups. The dogs showed a statistically significant reduction in characteristics of the LPR before and after treatment, as measured by clinical signs (Group 1vs.4 p = 0.00, group 2 vs 4 p = 0.00, group 3 vs 4 p = 0,01), by endoscopy (1 vs 4 p = 0,01, 2 vs 4 p = 0,00, 3 vs 4 p = 0,03), and by histopathology (groups 1 vs 4 p = 0,00, 2 vs 4 p = 0,00, 3 vs 4 p = 0,03). The significant differences were noted between experimental groups, as measured by endoscopy (group 2vs 3 p = 0,04), and by relapse rate (groups 1 and 2 p = 0,03, groups 2 and 3 p = 0,01).

Conclusions

The three treatment protocols administered to dogs improved clinical, endoscopic and histological status. However, oral administration of meloxicam for 3 weeks, followed by prednisone for 3 weeks, appeared to be the most successful treatment. These patients remained asymptomatic for 6 months.

Emergence of nasal chondrosarcoma in a dog with nasal polyposis

Whilst the malignant transformation of nasal polyps or secondary development of nasal neoplasia after chronic inflammation is likely to be relatively rare, this potential complication should be considered, and the clinician should be vigilant for evidence of malignant transformation.

Dedifferentiated Chondrosarcoma in the Dog and Cat: A Case Series and Review of the Literature

This retrospective case series describes seven dogs and one cat diagnosed with dedifferentiated chondrosarcoma, an uncommon, aggressive variant of chondrosarcoma. The purpose of the study is to describe clinical, imaging, and histopathological findings of this tumor. Medical records and the diagnostic laboratory database at Colorado State University from 2000 to 2015 were reviewed and complete medical records were available for the eight animals in this report. Similar to what has been reported in people, poor long-term survival and high metastatic rate, particularly to the lungs, was observed in our case series. A bimorphic pattern on imaging (radiographs, computed tomography, and MRI) consisting of mineralized and nonmineralized areas was seen mirroring the high-grade sarcomatous component adjacent to a low-grade chondroid component seen histopathologically. A review of the human literature including suspected etiology, imaging findings, histopathology, and survival times with various treatment options is presented. This article describes the first reported cases of dedifferentiated chondrosarcoma in the veterinary literature. Early accurate recognition could lead to treatment plans tailored to this variant.

Spatial Patterns and Impacts of Environmental and Climatic Factors on Canine Sinonasal Aspergillosis in Northern California

Sinonasal aspergillosis (SNA) causes chronic nasal discharge in dogs and has a worldwide distribution, although most reports of SNA in North America originate from the western USA. SNA is mainly caused by Aspergillus fumigatus, a ubiquitous saprophytic filamentous fungus. Infection is thought to follow inhalation of spores. SNA is a disease of the nasal cavity and/or sinuses with variable degrees of local invasion and destruction. While some host factors appear to predispose to SNA (such as belonging to a dolichocephalic breed), environmental risk factors have been scarcely studied. Because A. fumigatus is also the main cause of invasive aspergillosis in humans, unraveling the distribution and the environmental and climatic risk factors for this agent in dogs would be of great benefit for public health studies, advancing understanding of both distribution and risk factors in humans. In this study, we reviewed electronic medical records of 250 dogs diagnosed with SNA between 1990 and 2014 at the University of California Davis Veterinary Medical Teaching Hospital (VMTH). A 145-mile radius catchment area around the VMTH was selected. Data were aggregated by zip code and incorporated into a multivariate logistic regression model. The logistic regression model was compared to an autologistic regression model to evaluate the effect of spatial autocorrelation. Traffic density, active composting sites, and environmental and climatic factors related with wind and temperature were significantly associated with increase in disease occurrence in dogs. Results provide valuable information about the risk factors and spatial distribution of SNA in dogs in Northern California. Our ultimate goal is to utilize the results to investigate risk-based interventions, promote awareness, and serve as a model for further studies of aspergillosis in humans.

Use of a frameless computed tomography-guided stereotactic biopsy system for nasal biopsy in five dogs

CASE DESCRIPTION

5 dogs (median age, 9 years; median body weight, 31 kg [68.2 lb]) with undefined nasal masses were examined after undergoing CT of the head and nasal biopsy via a rostral rhinoscopic or unaided (blind) approach because histologic results for collected biopsy specimens (inflammatory, necrotic, or hemorrhagic disease) suggested the specimens were nonrepresentative of the underlying disease process identified via CT (aggressive or malignant disease).

CLINICAL FINDINGS

Clinical signs at the time dogs were evaluated included open-mouth breathing, sneezing, or unilateral epistaxis. Histologic findings pertaining to the original biopsy specimens were suggestive of benign processes such as inflammation. In an attempt to obtain better representative specimens, a frameless CT-guided stereotactic biopsy system (CTSBS) was used to collect additional biopsy specimens from masses within the nasal and sinus passages of the dogs. The second set of biopsy specimens was histologically evaluated.

TREATMENT AND OUTCOME

Histologic evaluation of biopsy specimens collected via the CTSBS revealed results suggestive of malignant neoplasia (specifically, chondrosarcoma, hemangiopericytoma, or undifferentiated sarcoma) for 3 dogs, mild mixed-cell inflammation for 1 dog, and hamartoma for 1 dog. No complications were reported. These findings resulted in a change in treatment recommendations for 3 dogs and confirmed that no additional treatment was required for 1 dog (with hamartoma). For the remaining dog, in which CT findings and clinical history were strongly suggestive of neoplasia, the final diagnosis was rhinitis.

CLINICAL RELEVANCE

Biopsy specimens were safely collected from masses within the nasal and sinus passages of dogs by use of a frameless CTSBS, allowing a definitive diagnosis that was unachievable with other biopsy approaches.

Aspergillus and aspergilloses in wild and domestic animals: a global health concern with parallels to human disease

The importance of aspergillosis in humans and various animal species has increased over the last decades. Aspergillus species are found worldwide in humans and in almost all domestic animals and birds as well as in many wild species, causing a wide range of diseases from localized infections to fatal disseminated diseases, as well as allergic responses to inhaled conidia. Some prevalent forms of animal aspergillosis are invasive fatal infections in sea fan corals, stonebrood mummification in honey bees, pulmonary and air sac infection in birds, mycotic abortion and mammary gland infections in cattle, guttural pouch mycoses in horses, sinonasal infections in dogs and cats, and invasive pulmonary and cerebral infections in marine mammals and nonhuman primates. This article represents a comprehensive overview of the most common infections reported by Aspergillus species and the corresponding diseases in various types of animals.

Evaluation of the ventro 20° rostral-dorsocaudal oblique radiographic projection for the investigation of canine nasal disease

OBJECTIVE

To assess the ventro 20° rostral-dorsocaudal oblique projection for canine nasal disease as an alternative to the dorsoventral intra-oral view.

MATERIALS AND METHODS

Thirty-one dogs with nasal disease underwent radiography and computed tomography with a final diagnosis of underlying cause achieved through rhinoscopy, biopsy or cytology. Three independent observers, blinded to diagnosis, reviewed the nasal radiographs on two separate occasions. Intra- and inter-observer agreement and level of confidence on radiographic diagnosis were evaluated and radiographic diagnosis was compared with computed tomography and definitive diagnosis.

RESULTS

The ventro 20° rostral-dorsocaudal oblique projection of canine nasal cavities was feasible in anaesthetised dogs and gave diagnostic quality images in most dogs. Assessment of this view showed moderate to substantial agreement with computed tomography diagnosis but gave lower confidence in diagnosis. Interpretation of this radiographic projection had substantial to almost perfect repeatability but moderate reproducibility.

CLINICAL SIGNIFICANCE

The ventro 20° rostral-dorsocaudal oblique projection may be used as a valuable initial screening tool for canine nasal pathology in practices without access to advanced imaging, although computed tomography is still likely to provide greater diagnostic information.

Idiopathic lymphoplasmacytic rhinitis in 33 dogs

Idiopathic lymphoplasmacytic rhinitis (LPR) is recognised frequently in dogs with clinical signs typical of other chronic nasal diseases. The purpose of this study was to determine clinical signs, survey radiographic, rhinoscopic and histologic abnormalities and the response to therapy in dogs with LPR. It was a retrospective study of 33 client-owned animals of various breeds and ages that had been diagnosed with LPR. During the study period, a total of 110 dogs were diagnosed with nasal disease, of which 33 (30%) were diagnosed with idiopathic LPR. The median age was 9 years (range 2.3–17 years) and there were 15 female and 18 male dogs. The majority of dogs showed a mucoid nasal discharge, bilateral stertor and no overt radiographic changes. The most common finding on rhinos copy was hyperaemic nasal mucous membranes with mucoid material accumulation within the nasal cavity. In all 33 dogs bacterial culture yielded no pathogenic bacteria and fungal culture was negative. Histologically, all 33 dogs showed lymphoplasmacytic infiltration within the nasal mucosa. All 33 dogs were treated with systemic and topical corticosteroids for varying lengths of time and dosing intervals. Eleven dogs were treated with concurrent cyclosporine and three dogs underwent allergy testing followed by desensitisation therapy. The best response was seen in the dogs that underwent desensitisation therapy, followed by those treated with corticosteroids and cyclosporine.

Characteristics of canine nasal discharge related to intranasal diseases: a retrospective study of 105 cases

OBJECTIVES

To compare characteristics of nasal discharge caused by different intranasal aetiologies in dogs.

METHODS

Medical records of 105 dogs with nasal discharge due to intranasal disease were retrospectively reviewed with special focus on composition, severity, duration and localisation of discharge. On the basis of diagnostic findings, cases were classified into different disease groups and characteristics of discharge were compared between groups.

RESULTS

Cases were classified as having non-specific rhinitis (n=42), nasal neoplasia (n=23), foreign bodies (n=21), nasal mycosis (n=7) and miscellaneous disorders (n=13). Dogs with foreign bodies or nasal mycosis were significantly younger. Mucous components of discharge occurred more often in non-specific rhinitis and nasal neoplasia, although haemorrhagic components predominated in nasal neoplasia when discharge lasted ê14 days. Pure or mixed haemorrhagic discharge was significantly more common with nasal neoplasia, foreign bodies and nasal mycosis. Purulent components were associated with longer duration of discharge and predominantly seen in non-specific rhinitis and foreign bodies. Dogs with foreign bodies were presented earlier and sneezing was more frequent. Nasal stridor was significantly more often observed in dogs with nasal neoplasia.

CLINICAL SIGNIFICANCE

Characteristics of nasal discharge and associated clinical signs might aid in planning the diagnostic approach, but a combination of diagnostic techniques is still required to confirm a diagnosis.

Canine nasal disease

Nasal disease often manifests as nasal discharge with or without other nasal signs. Attention to signalment, history, and physical examination findings often facilitates a differential diagnosis. Imaging techniques and tissue sampling for microscopic examination are usually necessary for diagnosis. Advanced imaging offers important advantages over traditional skull radiographs but is less widely available and more costly. Bacterial culture is seldom beneficial, and fungal culture is reserved for cases likely to have fungal rhinitis. Nasal biopsy is required to confirm a specific diagnosis and is always required for diagnosis of specific tumor type or for inflammatory rhinitis.

Late presentation of canine nasal tumours in a UK referral hospital and treatment outcomes

OBJECTIVES

To determine the computed tomographic stage of dogs with nasal tumours in a UK referral population, and whether stage, time to referral and treatment correlates with outcome.

METHODS

Retrospective review of clinical records and computed tomography scans of dogs with nasal tumours.

RESULTS

Dogs (n=78) presented to a referral practice in the UK with suspected nasal tumours are presented with more late stage tumours than dogs in the USA and Japan. Length of time from initial presentation to referral did not correlate with tumour stage at diagnosis. Median survival times for radiotherapy-treated dogs in this population are equivalent to those previously reported for late stage nasal tumours.

CLINICAL SIGNIFICANCE

Dogs with nasal tumours are presented late in the course of disease in the North West of England. Dogs with clinical signs consistent with a nasal tumour should have timely imaging and biopsy, in order to make prompt treatment decisions. Although survival times are comparable with previous reports and radiotherapy is a valid treatment option for dogs with late stage disease, better outcomes are likely to be achievable with earlier treatment.

Trephination of the frontal sinuses and instillation of clotrimazole cream: a computed tomographic study in canine cadavers

OBJECTIVE

To use computed tomography (CT) to assess the distribution of surgically administered clotrimazole cream and associated filling of the frontal sinuses and caudal aspect of the nasal cavities in canine cadavers.

STUDY DESIGN

Observational study.

ANIMALS

Small (n = 1) and medium-large (n = 11) breed canine cadavers.

METHODS

CT scans of 12 cadaveric canine heads were used to confirm absence of sinonasal disease. Then after creating an opening into the left and right frontal sinuses with a 3.2 mm Steinmann pin at standardized landmarks, clotrimazole cream (20 g) was instilled into each side. Postoperative CT scans of the heads was used to assess the distribution and degree of filling of the sinonasal cavities with clotrimazole cream, and to identify any damage to local structures.

RESULTS

Filling was excellent in 22 sinuses, very poor in 2, and excellent in all caudal nasal cavities. Two cadavers had damage: unilateral penetration of the cranium (2) and unilateral penetration of the lateral sinus wall (1).

CONCLUSION

Excellent filling of most of the frontal sinuses and caudal nasal cavity of cadavers with clotrimazole cream is achieved when administered by this technique. Damage to local structures may occur intraoperatively using this technique.

Sinonasal aspergillosis in dogs: a review

Sinonasal aspergillosis is an uncommon, yet debilitating and often frustrating condition to treat in dogs despite years of research evaluating pathogenesis, diagnosis and treatment. The disease is most commonly caused by non-invasive fungal infection, thought to be secondary to altered innate and/or adaptive immune responses. Attempts to confirm this have however failed. A variety of conflicting opinions regarding the diagnosis and treatment of sinonasal aspergillosis exist. Often the use of a particular treatment protocol is based upon personal or regional preference. Evaluation of the veterinary literature demonstrates that the evidence base in support of individual treatment recommendations is weak. A number of recent publications have helped to expand the current knowledge base and therefore our understanding of important practicalities for both diagnostic options and treatment protocols. The following review examines the current evidence for the pathogenesis of sinonasal aspergillosis in dogs, as well as the various diagnostic options. The available evidence for frequently utilised -therapeutic options and their likely outcomes is also explored.

Diagnostic accuracy of brush cytology in canine chronic intranasal disease

BACKGROUND

Most cases of canine chronic intranasal disease cannot be differentiated based on clinical examination alone, and biopsy is often required for a definitive diagnosis. Nonsurgical cytologic and histologic biopsy techniques represent desirable diagnostic approaches.

OBJECTIVE

The aim of this retrospective study was to determine the diagnostic accuracy of brush cytology in differentiating non-neoplastic and neoplastic diseases in dogs with chronic intranasal disease.

METHODS

Cytologic samples of lesions in dogs with chronic intranasal disease were obtained by brushing over a 12-year period. All dogs had complete physical examinations as well as radiographic, rhinoscopic, and cytologic evaluation. Histologic diagnosis, follow-up clinical information, or both were used as the gold standard, and dogs free of disease or with no progression of disease at 1 year were considered negative for neoplasia. Indicators of performance of brush cytology in detecting neoplasia were calculated and included sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio.

RESULTS

Samples of nasal brushings from 138 dogs were evaluated. Of 62 cases of neoplastic disease, true-positive and false-negative diagnoses were made using cytologic evaluation in 44 (71.0%) and 18 (29.0%) cases, respectively. False-negative diagnoses of neoplasia were not attributed to low cellularity, but to the presence of inflammatory cells that masked neoplastic cells. Brush cytology had a sensitivity of 0.71, specificity of 0.99, positive likelihood ratio of 53.94, negative likelihood ratio of 0.29, and diagnostic odds ratio of 188.33.

CONCLUSIONS

Brush cytology has good diagnostic accuracy for chronic intranasal lesions in dogs.

Frontal sinus depth at four landmarks in breeds of dog typically affected by sinonasal aspergillosis

The objective of this study was to assess whether the frontal sinuses in dogs with aspergillosis and of breeds typically affected by this condition were deeper at a more caudal location. CT scans of the head performed at the Small Animal Teaching Hospital, University of Liverpool, between April 2007 and March 2009 for dogs diagnosed with aspergillosis (group 1) and unaffected dogs of similar breeds (group 2) were selected for study. Sinus depth was measured at four standardised locations from reconstructed images of these CT scans. Data were compared for differences in sinus depth between groups and between landmarks. No significant difference was found between measurements within individual dogs or for each of the various landmarks between groups. Difference in depth of the sinuses between landmarks was significant (P<0.001). Sinus depth was significantly greater at the more caudal landmarks and was shallowest at the previously recommended landmark for sinus entry. In 54 per cent of dogs, the frontal sinus depth measured less than or equal to 2 cm at one or more of the landmarks. Sinus entry at the deepest point will reduce the risk of accidentally damaging underlying structures. This may be approximately 1 cm caudal, in breeds of dog that typically develop aspergillosis, to a previously suggested landmark.

Idiopathic osseous hyperplasia of the nasal turbinates in a Welsh terrier

A three-year-old Welsh terrier was presented with a 6-month history of progressive stertor, exercise intolerance and sneezing which was unresponsive to symptomatic treatment. A large calcified mass occupying the entire rostral right nasal cavity was defined with computed tomography. The mass was completely removed via a dorsal rhinotomy. Histopathological examination of the mass revealed osseous hyperplasia of the nasal turbinates. The excision led to complete resolution of clinical signs and there has been no recurrence 18 months after surgery.

Nasopharyngeal Tooth Foreign Body in a Dog

An 8-year-old Shih-tzu dog was presented with a 2-week history of cough and nasal discharge. Upon presentation, the dog had constant open-mouth breathing with stertor and blood-tinged mucopurulent nasal discharge. Oral examination revealed a missing right mandibular second premolar tooth and severe periodontal disease. Computed tomography showed a radiodense, retropharyngeal foreign body. The foreign body was removed using caudal rhinoscopy. The foreign body was the right mandibular second premolar covered by thick calculus.

Acute phase protein concentrations in dogs with nasal disease

The concentrations of C-reactive protein (CRP), serum amyloid A, haptoglobin (Hp) and α(1)-acid glycoprotein were measured in dogs with clinical signs of nasal disease and compared with those of healthy dogs in order to determine the expression of these proteins in cases of canine nasal disease. A significant difference (P<0.001) between the symptomatic group and the control group was found for both CRP and Hp. Among the animals with nasal disease, a significant intergroup difference (P<0.05) was found in the expression of Hp between dogs with aspergillosis and those with chronic rhinitis.

Clinical findings, rhinoscopy and histological evaluation of 54 dogs with chronic nasal disease

Nasal diseases are very common in dogs and rhinoscopy is often required for a definitive diagnosis. Rhinoscopy, while superficial in nature, can guide the clinician to the final diagnosis. In this study, rhinoscopy was performed on 54 dogs with symptoms of chronic nasopharyngeal disease. The endoscopic diagnosis of neoplasia or chronic nasal inflammation was validated with histological examination of pathological samples, in order to evaluate the degree of concordance between endoscopic findings and histological diagnosis. The agreement between endoscopy and histology was tested by application of Cohen's kappa coefficient. We conclude that correlation between endoscopic results and histological diagnosis, expressed by a Cohen's kappa coefficient of 0.73, is only possible with a constant cooperation between the clinician and the pathologist.

Association of magnetic resonance imaging findings and histologic diagnosis in dogs with nasal disease: 78 cases (2001-2004)

OBJECTIVE-To determine whether magnetic resonance imaging (MRI) features correlated with histologic diagnosis in dogs with nasal disease. DESIGN-Retrospective case series. ANIMALS-78 Dogs undergoing MRI for evaluation of nasal disease. PROCEDURES-Medical records and MRI reports of dogs were reviewed to identify MRI features associated with histologic diagnosis. Features evaluated were presence of a mass effect, frontal sinus involvement, sphenoid sinus involvement, maxillary recess involvement, nasopharyngeal infiltration by soft tissue, nasal turbinate destruction, vomer bone lysis, paranasal bone destruction, cribriform plate erosion, and lesion extent (ie, unilateral vs bilateral). RESULTS-33 Dogs had neoplastic disease, 38 had inflammatory rhinitis, and 7 had fungal rhinitis. Lesion extent was not significantly associated with histologic diagnosis. Absence of a mass effect was significantly associated with inflammatory disease. However, presence of a mass was not specific for neoplasia. In dogs with evidence of a mass on magnetic resonance (MR) images, nasal turbinate destruction, frontal sinus invasion, and maxillary recess invasion were not useful in distinguishing neoplastic from nonneoplastic disease, but cribriform plate erosion, vomer bone lysis, paranasal bone destruction, sphenoid sinus invasion, and nasopharyngeal invasion were. CONCLUSIONS AND CLINICAL RELEVANCE-Results suggested that in dogs with nasal disease, the lack of a mass effect on MR images was significantly associated with inflammatory disease. In dogs with a mass effect on MR images, vomer bone lysis, cribriform plate erosion, paranasal bone destruction, sphenoid sinus invasion by a mass, and nasopharyngeal invasion by a mass were significantly associated with a diagnosis of neoplasia.