Associations between age, parity, hormonal therapy and breed, and pyometra in Finnish dogs

Association between bacterial pathogenicity, endometrial histological changes and clinical prognosis in canine pyometra

Despite the high frequency and clinical relevance of canine pyometra, its pathogenesis remains poorly understood. In this study, the clinical data, histopathological alterations, and microbiological findings of 39 dogs with pyometra were analyzed to assess possible associations. The mean age of the affected animals was 9.6 ± 3.8 years; 76.3 % (29/38) had open cervix pyometra, 88 % (22/25) had tachypnea, 71 % (27/38) had anorexia, and 60.5 % (23/38) had leukocytosis. Histopathological analysis revealed that 66.5 % (26/39) of the uteri had a high degree of inflammation (score 4). Third-degree hyperplasia of the endometrial epithelium (72 %, 28/39) and intralesional or intrauterine bacteria (66.5 %, 26/39) were identified in most animals. Bacterial isolates were obtained from 82 % (32/39) of the uterine contents and five bacterial species were identified. Escherichia coli, classified in phylogroup B2, is associated with virulent adhesion genes (fimH, focG, and papC), and serum resistance (traT) was the most common isolate. There was an association between the detection of papC in E. coli isolates and higher necrosis scores. Additionally, the necrosis score was positively associated with the length of hospitalization, with each point increase in the necrosis score leading to two more days of hospitalization. These results suggest that papC-positive E. coli play an important role in the severity of pyometra in dogs. The present study revealed the possibility of using this virulence gene to better understand the prognosis of the disease in an affected animal.

Canine Pyometra: A Short Review of Current Advances

Pyometra, characterized by the accumulation of purulent exudate in the uterus, is the most prevalent reproductive disease in canines. While the disease often begins with mild local symptoms, it can escalate into peritonitis, sepsis, and multi-organ dysfunction, thereby posing a significant threat to life. Despite the high incidence and recognized significance of canine pyometra, gaps persist in our understanding of its epidemiology, etiology, and pathogenesis. Recent studies have, however, broadened our comprehension of this disease, shedding light on potential new infection sources, etiologies, and the application of clinical predictive biomarkers and new therapeutic protocols. This study aimed to review the current understanding of canine pyometra, with particular emphasis on the latest research concerning its etiology and epidemiology. Furthermore, it addressed key research questions and proposed directions for future investigations into various facets of canine pyometra.

T-cell lymphoma infiltrating the uterus and ovaries of a Golden Retriever: a case report

BACKGROUND

To the best of our knowledge, this is the first report of female genital system infiltration of T-cell lymphoma in veterinary literature.

CASE PRESENTATION

A 1.5-year-old, intact female Golden Retriever was referred due to melena and hyporexia that lasted for three weeks. Fever (40.5℃), tachycardia, tachypnoea, pale mucous membranes, and purulent vaginal discharge were identified on physical examination. Blood analyses revealed leucocytosis, anaemia, hypoalbuminemia, and increased lactate and C-reactive protein levels. On abdominal radiography, the small intestine was moderately deviated because of an oval-shaped mass (13 cm × 8.7 cm) located in the mid-abdomen. An enlarged tubular-shaped structure that had the opacity of soft tissue located in dorsal to the bladder to the middle of the abdomen, and an oval-shaped mass (5.28 cm × 3.26 cm), which was suspected to be a medial iliac lymph node located at the sixth to seventh lumbar level. Abdominal ultrasonography revealed gas and fluid in the lumen of the uterine horn with a severely thickened wall, round enlarged lymph nodes around the genitourinary system, and free fluid in the abdominal cavity. Based on these results, pyometra was suspected, and an exploratory laparotomy was performed for ovariohysterectomy. The resected ovary and uterus were macroscopically hypertrophied. Histopathological examination of the ovary and uterus revealed neoplastic proliferation of large round cells with strong immunoreactivity for CD3, indicating T-cell lymphoma. Therefore, the young dog was diagnosed with genital lymphoma.

CONCLUSIONS

The present report describes T-cell lymphoma infiltrating the uterus and ovaries in a young dog, which is rarely diagnosed and could aid in the differential diagnosis of genital diseases in young dogs.

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

This Scientific Report addresses a mandate from the European Commission according to Article 31 of Regulation (EC) No 178/2002 on the welfare of cats and dogs in commercial breeding establishments kept for sport, hunting and companion purposes. The aim was to scrutinise recent recommendations made by the EU Platform on Animal Welfare Voluntary Initiative on measures to assist the preparation of policy options for the legal framework of commercial breeding of cats and dogs. Specifically, the main question addressed was if there is scientific evidence to support the measures for protection of cats and dogs in commercial breeding related to housing, health considerations and painful procedures. Three judgements were carried out based on scientific literature reviews and, where possible a review of national regulations. The first judgement addressed housing and included: type of accommodation, outdoor access, exercise, social behaviour, housing temperature and light requirements. The second judgement addressed health and included: age at first and last breeding, and breeding frequency. Judgement 3 addressed painful procedures (mutilations or convenience surgeries) and included: ear cropping, tail docking and vocal cord resections in dogs and declawing in cats. For each of these judgements, considerations were provided indicating where scientific literature is available to support recommendations on providing or avoiding specific housing, health or painful surgical interventions. Areas where evidence is lacking are indicated.

Pyometra in Small Animals 3.0

Pyometra is a common disease in intact bitches and queens and occurs, although less frequently, in most other female pets. In bitches and queens, the illness is generally diagnosed within 4 months after estrus, in middle-aged to older individuals. Complications such as peritonitis, endotoxemia, and systemic inflammatory response syndrome are not uncommon and associated with more severe illness. Ovary-sparing surgical options such as hysterectomy could be considered in individuals with high-risk for detrimental side effects of spaying or without infection of the uterus but has not yet been evaluated for safety in pyometra.

How size and genetic diversity shape lifespan across breeds of purebred dogs

While the lifespan advantage of small body size and mixed breed status has been documented repeatedly, evidence for an effect of genetic diversity across dog breeds is equivocal. We hypothesized that this might be due to a strong right-censoring bias in available breed-specific lifespan estimates where early-dying dogs from birth cohorts that have not died off completely at the time of data collection are sampled disproportionately, especially in breeds with rapidly growing populations. We took advantage of data on owner reported lifespan and cause of death from a large public database to quantify the effect of size and genetic diversity (heterozygosity) on mortality patterns across 118 breeds based on more than 40,000 dogs. After documenting and removing the right-censoring bias from the breed-specific lifespan estimates by including only completed birth cohorts in our analyses, we show that small size and genetic diversity are both linked to a significant increase in mean lifespan across breeds. To better understand the proximate mechanisms underlying these patterns, we then investigated two major mortality causes in dogs - the cumulative pathophysiologies of old age and cancer. Old age lifespan, as well as the percentage of old age mortality, decreased with increasing body size and increased with increasing genetic diversity. The lifespan of dogs dying of cancer followed the same patterns, but while large size significantly increased proportional cancer mortality, we could not detect a significant signal for lowered cancer mortality with increasing diversity. Our findings suggest that outcross programs will be beneficial for breed health and longevity. They also emphasize the need for high-quality mortality data for veterinary epidemiology as well as for developing the dog as a translational model for human geroscience.

Pyometra does not affect some molecular quality-related parameters of canine oocytes

Cystic endometrial hyperplasia-pyometra complex (CEH/P) significantly perturbs the reproductive performance of affected bitches and ovariohysterectomy (OHE) is a commonly applied treatment. Thus the only way to take advantage of the genetic potential of valuable females is application of assisted reproductive techniques (ART) mainly in vitro embryo production (IVP) or in some exceptional cases animal cloning by somatic cell nuclear transfer (SCNT). The aim of our study was to examine a potential effect of the CEH/P status on the quality of oocytes from females subjected to OHE. In total, 828 immature oocytes collected from ovaries of 33 bitches (21 control, 12 CEH/P) were subjected to genetic analyses (mRNA expression of two maternal-effect genes: GDF-9, OCT4 and mitochondrial DNA (mtDNA) content). Oocytes of CEH/P females were characterized by a higher mtDNA content (471 696) than gametes of their healthy counterparts (368 175; P<0.005). Transcripts for the two genes were detected in all samples and the mRNA level was not affected by the CEH/P status. In conclusion, the CEH/P complex does not exert a negative effect on oocyte quality reflected by the two parameters examined in this study.

Ovarian Cysts in the Bitch: An Update

Functional ovarian cysts occur as solitary or multiple fluid-filled structures of variable size that are unilateral or bilateral in the bitches of age 6-8 years. Though the pathogenesis is obscure, insufficient LH surge, intrafollicular changes in gonadotrophin receptors and growth factors are the possible reasons behind the occurrence of hormonally active ovarian cysts that predisposes the bitch to the development of cystic endometrial hyperplasia-pyometra complex and occasionally hyper estrogenism. In the presence of suggestive signs, ultrasonography is the practical imaging modality for the clinical diagnosis that can be confirmed by assay of ovarian steroids and histopathology. Medical management with gonadotrophin-releasing hormone analogues and human chorionic gonadotrophin is not preferred as they are not always successful. As uterine pathologies are highly likely by the time of diagnosis, ovariohysterectomy is the treatment of choice for the follicular and luteal cysts. Understanding the cellular and molecular changes in the hypothalamo-hypophyseal ovarian axis will improve our understanding on the canine ovarian cysts.

Highlights on the Canine Prostatic Specific Esterase (CPSE): A diagnostic and screening tool in veterinary andrology

In the last years, the need to look for an accurate and precise diagnosis of prostatic diseases in dogs has grown. Among other diagnostic tools, the seric CPSE has been studied and identified as a valid and specific biomarker for prostatic disorders, since it can result significantly more elevated in dogs affected by several prostatic abnormalities, such as benign prostatic hyperplasia, bacterial prostatitis and prostatic carcinoma. Therefore, dosing CPSE in serum represents a new diagnostic and screening tool. Dosing CPSE in everyday clinical practice has three objectives: (a) the diagnosis of benign prostatic hyperplasia; (b) the preventive screening of prostatic disorders in healthy dogs; (c) the medical follow‐up in subjects with prostatic disorders during and after medical therapy. Neither circadian rhythms nor transrectal palpation performed during the andrological examination do affect CPSE. A sexual rest of at least 24 hr before dosing CPSE is recommended as it is affected by ejaculation.

Endometrial transcripts of proinflammatory cytokine and enzymes in prostaglandin synthesis are upregulated in the bitches with atrophic pyometra

Inflammatory markers of endometrial origin are valuable in order to differentiate the pyometra from cystic endometrial hyperplasia in the bitch. In the present study, we hypothesized that histological categorization would distinguish the differential regulation of the proinflammatory genes in the endometrium of bitches with pyometra. Ovariohysterectomy was done on bitches with confirmatory diagnosis of pyometra (n = 18). Using endometrium to myometrium ratio of 0.79 as threshold, the uteri (n = 8/group) were categorized into hyperplastic pyometra (HP) and atrophic pyometra (AP). Two samples were excluded as the diagnosis was inconclusive. In parallel, endometrial tissue was collected for total RNA extraction to study the differential expression of TLR4, IL-6, IL-8, COX-2 and PGFS through real time PCR. Diestrus uterus of non-pyometra bitches (n = 6) served as control. The mean fold change (2^-ΔΔCt) for the target genes was determined using β-actin as endogenous control and non-pyometra uterus as calibrator group. Except TLR4, other inflammatory genes were upregulated significantly by 1.82 to 3.74 times in the AP as compared to HP with maximum upregulation of COX-2 and PGFS. Further, correlation matrix with Spearman's rho revealed that IL-8 had strong positive correlation with COX-2 and PGFS in the AP group (P < 0.05). It is concluded that histological grading of pyometra into HP and AP revealed differential regulation of inflammatory cytokines and enzymes in the PG synthetic pathway in the canine endometrium that has diagnostic potential under clinical settings.

Histopathologic findings in uteri and ovaries collected from clinically healthy dogs at elective ovariohysterectomy: a cross-sectional study

Opinions on ovariohysterectomy (OHE) of bitches vary depending on region and country. In this descriptive, prospective cross-sectional study, uterine tracts and ovaries exhibiting gross pathologic findings (n = 76) were collected post-surgery from a reference population of 3,600 bitches (2.11% incidence) that underwent elective OHE during September to November 2013 and evaluated by histopathology examination. Data were evaluated by using descriptive statistics and chi-squared tests. Bitches were of crossbred background with average age 5 years (range 0.6–8.0 years) and most were nulliparous (69.7%) with no anamnesis of reproductive diseases (81.6%). Frequencies of proestrus, estrus, and diestrus were 42.1%, 6.6%, and 19.7%, respectively. The presence of mammary gland masses (5.3%) significantly correlated with histopathologic findings in ovaries and age of the bitch (p < 0.05). Predominant uterine histopathologies included cystic endometrial hyperplasia, periglandular fibrosis, lymphoplasmocytary endometritis, and adenomyosis (19.7%, 14.5%, 4.0%, and 2.6%, respectively). In ovaries, hyperplasia of rete ovarii, follicular cysts, oophoritis, adenoma of the rete ovarii, cysts of superficial structures, and granulosa cell tumors (10.5%, 10.5%, 7.9%, 4.0%, 2.6%, and 2.6%, respectively) were observed. The results reveal the presence of subclinical pathologies in healthy bitches, suggesting that OHE at an early age is beneficial for prevention of reproductive pathologies.

Molecular aspects of uterine diseases in dogs

Uterine diseases are common in dogs, particularly in countries where elective spaying is not usually performed. The associated clinical illnesses may be of varying degree ranging from merely decreased fertility to a critical pyometra requiring intensive care to survive. The diagnosis of some uterine diseases is generally uncomplicated, such as in a classic pyometra presenting with enlarged, fluid-filled uterus, purulent vaginal discharge and characteristic signs of illness or in other disorders associated with uterine enlargement. However, it can be more puzzling in diseases with normal uterine size and very mild or obscure clinical signs. It is important to recognize the uterine diseases early because of the risk of potentially life-threatening complications such as sepsis developing if treatment is delayed in cases where bacterial infection is present. In breeding bitches, an early diagnosis, that is when the disease has not developed extensively, will increase the possibility of non-surgical treatment options without increased risk and thereby also increasing chances of maintained fertility. Early diagnosis and treatment initiation are thus favourable for complete recovery, also in less severe uterine diseases and those without infection. Molecular markers are molecules in biological samples that can be measured for diagnostic purposes, outcome prediction, and for gaining more information about different physiological and pathological conditions. Examples of commonly evaluated markers include laboratory variables analysed in blood, urine, cytological or tissue biopsy samples. Regarding the genetic pre-disposition for different uterine diseases in dogs, information is lacking. Recently, the global gene expression in uterine tissue in dogs has been investigated more closely, and newly developed technologies provide excellent opportunities for identifying molecular markers worth exploring further. The focus of this review article is to highlight findings on markers relevant for diagnosis, prediction of prognosis and treatment outcome in the most common uterine diseases in dogs.

Assessment of the age for a preventive ultrasonographic examination of the prostate in the dog

The prostate commonly develops benign prostatic hyperplasia (BPH) in dogs over 5 years, while in aged dogs other pathological findings might be revealed by ultrasonographic exam. The aim of the present study was to estimate the most suitable age for a preventive ultrasonographic examination of the prostate in the dog. The prostate of 1003 intact male dogs of 64 different breeds, of different ages (1-18 years) and bodyweights (2-55 kg) was evaluated with ultrasound, irrespective of the reason for clinical examination. The age of each dog was expressed as the ratio between the actual age and the maximum longevity expected for the breed. Dogs were divided in two groups based on breeds' life expectancy as short life (SL) and long life (LL). The size of the prostate (normal, enlarged or small) and the presence of abnormal sonographic findings were recorded for each dog. The results of the present study indicate that the most suitable age for a preventive ultrasonographic exam of the prostate in the dog is approximately at 40% of its expected longevity, both in short and long life breeds, because at this age there is a strong possibility to be able to detect abnormal prostatic findings. In 47.5% of the dogs at least one abnormal finding of the prostate was revealed by ultrasonographic exam, while dogs with long life expectancy showed a significantly higher prevalence of abnormalities, than dogs with short life expectancy. The most frequent findings were the increase of prostatic size (33.5%) and the presence of at least one cyst (33.6%), with no difference between SL and LL dogs. In conclusion, a preventive examination of the prostate starting at 40% of expected longevity in dogs of short and long life breeds is strongly recommended for early detection of abnormalities, for scheduling specific follow up and for suggesting effective therapeutic protocols.

Blood pressure and heart rate during ovariohysterectomy in pyometra and control dogs: a preliminary investigation

BACKGROUND

Surgery causes a stress response, a physiologic response to trauma. The intraoperative surgical stress response in dogs diagnosed with pyometra has not previously been described. The aim of this study was to investigate the intraoperative surgical stress response, assessed by blood pressure and heart rate measurements, in dogs diagnosed with pyometra and healthy controls. All dogs were premedicated with acepromazine and methadone, anaesthesia was induced with propofol and maintained with isoflurane, where after the dogs were subjected to ovariohysterectomy.

RESULTS

Eight dogs diagnosed with pyometra and eight healthy controls were used. Systolic blood pressure and heart rate were measured to assess the surgical stress response. Additionally propofol dosage at induction of anaesthesia and the end-tidal isoflurane concentration were investigated. The surgery was split into four phases. Phase 0 was the period 10 min before the skin incision, phase 1 was skin incision and opening of abdomen, phase 2 was manipulation of uterine horns, lifting of the ovary with stretching of the mesovarium, ligation and transection of mesovarium and phase 3 was ligation and transection of cervix, removal of organs and closing of the abdomen. Dosage of propofol at induction of anaesthesia was 3.6 ± 1 mg/kg in dogs with pyometra and 4.1 ± 1 in healthy controls (P = 0.37). In both groups, systolic blood pressure increased between phase 1 and 2, from 87 ± 15 to 114 ± 19 mmHg in dogs with pyometra, and from 88 ± 18 to 106 ± 20 mmHg in healthy controls, (both P < 0.0001). Systolic blood pressure did not differ significantly between groups in any of the phases. Heart rate and end-tidal concentration of isoflurane did not differ significantly between phases or between groups.

CONCLUSIONS

The increased blood pressure at removal of ovaries during ovariohysterectomy suggests a pronounced noxious stimulus at this part of the procedure. In principle, the study parameters and response to surgery did not differ significantly between dogs with pyometra and healthy controls.

Vaginal fold prolapse in a dog with pyometra and ovarian papillary cystadenocarcinoma

CASE DESCRIPTION

A 7-year-old 42-kg (92.4-lb) sexually intact nulliparous female Italian Mastiff was examined because of a history of vaginal prolapse during diestrus.

CLINICAL FINDINGS

A physical examination revealed vaginal fold prolapse. Abdominal ultrasonography revealed an enlarged uterus with hypoechogenic content, corpora lutea in the ovaries, and a cyst in the right ovary. Hematologic abnormalities included leukocytosis, neutrophilia, mild anemia, and low Hct. Progesterone and estradiol concentrations were 9.36 ng/mL and 30.42 pg/mL, respectively, in serum and 72.72 ng/mL and 792 pg/mL, respectively, in the ovarian cystic fluid.

TREATMENT AND OUTCOME

Ovariohysterectomy was performed; the prolapsed tissue was repositioned by external manipulation and maintained in situ by temporary apposition of the vulvar lips with a retention suture. Anatomic and histologic examinations of the excised tissues revealed pyometra and papillary cystadenocarcinoma in the right ovary. The vaginal hyperplasia completely regressed at 35 days after surgery; 5 months after surgery, the dog's general condition was considered good.

CLINICAL RELEVANCE

Findings in this case were indicative of a hormonally active ovarian papillary cystadenocarcinoma in a female dog in diestrus. Hormone production by the cystadenocarcinoma was the predisposing factor that induced pyometra, mucosal hyperplasia, and vaginal fold prolapse in the dog. On the basis of these concurrent disorders, ovariohysterectomy was an appropriate treatment.

Diagnostic and prognostic markers for uterine diseases in dogs

Common uterine diseases in female dogs include cystic endometrial hyperplasia (CEH), mucometra, hydrometra and pyometra. It is important in clinical practice to recognize pyometra because it is potentially life-threatening due to the systemic illness induced by bacterial infection of the uterus. In contrast, the uterine content is sterile in CEH and mucometra/hydrometra, and clinical signs are mostly mild or absent. Optimal treatment depends on the type of uterine disease and its severity, but diagnosis and prognosis determination may be challenging and the diseases difficult to separate clinically. Diagnostic findings or biomarkers that may aid in the differentiation of the diseases are valuable, especially when several bitches are admitted with a fluid-filled uterus during night-time, and it has to be decided which patient to operate on first. Additionally, some variables may indicate outcome as measured by mortality or morbidity. If the uterus is not enlarged or fluid-filled, detection of uterine disease can be even more difficult. In this study, clinically useful variables with possible diagnostic or prognostic value for uterine diseases in dogs are discussed.

Medical treatment for pyometra in dogs

Pyometra is a reproductive disorder very common in bitches over 8 years of age in which physiological effects of progesterone on the uterus play a major role. The traditional therapy for pyometra is ovariohysterectomy. The main advantage of ovariohysterectomy over medical management is that it is both curative and preventive for recurrence of pyometra. However, surgery is associated with the risk of anaesthesia and renders the bitch sterile. During the last 10 years, numerous medical treatments have been proposed to treat both open and closed cervix pyometra. The most effective medical treatment with minor side effects seems to be the repeated administration of aglepristone with or without the additional treatment with low doses of prostaglandins.

Outcome of pyometra in female dogs and predictors of peritonitis and prolonged postoperative hospitalization in surgically treated cases

BACKGROUND

One of the most common diseases in intact bitches is pyometra--a potentially life-threatening disease associated with a variety of clinical and laboratory findings. The aims of the present study were to describe complications of the disease and to investigate clinically useful indicators associated with peritonitis and/or prolonged postoperative hospitalization.

RESULTS

A retrospective study was performed using records from 356 bitches diagnosed with pyometra during the years 2006-2007 at the University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden. Of the 356 bitches, 315 were surgically treated by ovariohysterectomy, 9 were medically treated and 32 were euthanized without treatment. In the surgically treated bitches, univariable associations between clinical and laboratory data, risk for prolonged hospitalization (≥ 3 days) and/or signs of peritonitis, were analyzed by Chi-square and Fisher's exact test. Logistic regression models were used to assess multivariable associations.The most common complication observed in surgically treated bitches was peritonitis (40 bitches), followed by urinary tract infection (19 bitches), wound infection (8 bitches), uveitis (6 bitches), and cardiac arrhythmia (5 bitches). Leucopenia and fever/hypothermia were associated with increased risk for peritonitis (18-fold and three-fold, respectively). Moderate to severe depression of the general condition, pale mucous membranes and leucopenia were associated with increased risk (seven-fold, three-fold, and over three-point-five-fold, respectively) for prolonged postoperative hospitalization.

CONCLUSIONS

Several clinically useful indicators were identified. Leucopenia was the most important marker, associated with 18-fold increased risk for peritonitis and an over three-point-five increased risk for prolonged hospitalization. Fever/hypothermia, depression and pale mucous membranes were associated with increased risk for peritonitis and/or prolonged hospitalization. The results of the present study may be valuable for identifying peritonitis and predicting increased morbidity in surgically treated bitches with pyometra.

A retrospective study of pyometra at five RSPCA hospitals in the UK: 1728 cases from 2006 to 2011

A retrospective cross-sectional study was used to analyse pyometra cases at five RSPCA Animal Hospitals across the UK from 2006 to 2011. A total of 1728 cases of pyometra were recovered from a female dog outpatient caseload of 78,469 animals, giving a total prevalence of 2.2 per cent over the study period. There was an annual increase in the incidence of pyometra within the population, while elective ovariohysterectomy caseload has declined. There were variations in breed and age at presentation. Bullmastiffs (P<0.0001), golden retrievers (P=0.001) and dogue de Bordeaux (P=0.008) were over-represented in the pyometra population when compared with the female dog outpatient caseload. Mean age at presentation was 7.7 years. Some breeds presented at a significantly lower age, including dogue de Bordeaux (mean age 3.3 years) and bullmastiffs (mean age 5.4 years), while others presented as older dogs, including Yorkshire terriers (mean age 9.4 years) and border collies (mean age 10.3 years). Surgical mortality rate at the Greater Manchester Animal Hospital was 3.2 per cent. Pyometra is of significant welfare concern, and also has cost implications, particularly in charity practice. These results serve to highlight this condition so that future change in charity practice caseload can be anticipated and strategies can be directed to improve animal welfare.

AAHA canine life stage guidelines

Guidelines are offered to guide the veterinary practitioner in designing a comprehensive, individualized wellness plan for each stage of a dog's life. Life stages are defined by both age and breed characteristics for practical purposes. Each patient visit should use an individualized approach to patient handling, preventive care, and early disease detection. Environment, behavior, nutrition, parasite control, vaccinations, dental care, zoonotic disease control, safety, and reproductive health should be addressed.

A breed-matched case-control study of potential risk-factors for canine pyometra

The objective was to evaluate plausible risk-factors for pyometra, a common disease affecting almost 25% of all (unspayed) female dogs before 10 years of age. Because of the strong breed-predilection, an age- and breed-matched case-control study was undertaken on 87 pairs (pyometra-cases and healthy controls) from five breeds (Rottweiler (n = 13), Collie (n = 8), Golden retriever (n = 24), Labrador retriever (n = 16) and German shepherd dog (n = 26)). The mean age was 7.9 y (range 0.8-13.8 y). Variables analyzed included pseudopregnancy, age at first oestrus, length of and regularity of the interoestrus interval, hormone treatments, nulliparity, number of parities, age at first whelping, previous urinary tract infections and mammary tumours. Data were modelled multivariably using matched-pair conditional logistic regression. Analysing interactions with breed, previous pregnancy was statistically associated with pyometra. When amalgamated, in three breeds previous pregnancy was protective (Rottweiler, Collie, Labrador retriever) and in one breed statistically intermediate (German shepherd dog) when compared to the baseline (Golden retriever). Previous pregnancy was a statistically significant factor that had a protective effect against pyometra in some breeds but not in the Golden retriever breed. These findings indicate that protective- and risk-factors may vary between different breeds. The obvious problem with low power and limited possibility for extrapolation, using few dogs in few breeds, is acknowledged. However, it is suggested that failure to control for the confounding effect of breed, especially in epidemiological studies on dog diseases, may lead to potentially erroneous conclusions.

Pseudo-placentational endometrial cysts in a bitch

Cystic alterations of the canine endometrium compromise reproduction and fertility of the bitch and may lead to life-threatening diseases, such as pyometra. Even without clinical evidence, reduction of the uterine lumen by cysts implicates disturbances during migration, nidation and development of the embryo. Several studies point to the high variability of morphology of uterine endometrial cysts but they lack detailed analyses of alterations. In the present study, immunohistochemistry was used to investigate the expression of steroid hormone receptors (oestrogen, progesterone), proliferation activity, inflammation and infection in the cystic affected tissue regions in contrast to the normal endometrium. Oestrogen receptor expression showed a high density of receptors throughout the surface epithelial cells, crypt epithelial cells, glandular epithelial cells and stromal cells of the normal endometrium as well as the cystic affected regions. Proliferation in the cysts was verified in the middle and basal cells of the crypts. Neither in the endometrium nor in the cysts inflammatory processes or evidence of infection could be detected. Furthermore, lectin histochemistry and electron microscopic methods showed that lectin binding patterns and cell morphology of internal epithelial lining and surface epithelium of the cysts can be used to characterize and distinguish different types of cystic alterations. Analogies between epithelial cells of the glandular chambers of the canine placenta and the cystic cellular morphology, steroid hormone receptor distribution as well as lectin binding patterns of the endometrial cysts, as observed in this study, suggest to introduce the term 'pseudo-placentational endometrial cysts'.

Epidermal growth factor, transforming growth factor-alpha, and epidermal growth factor receptor expression and localization in the canine endometrium during the estrous cycle and in bitches with pyometra

Gene expression and immunohistochemical localization of epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and epidermal growth factor receptor (EGF-R) were compared between the endometrium of bitches (Canis familiaris) with pyometra accompanied by cystic endometrial hyperplasia (CEH) and that of healthy bitches at similar stages of the estrous cycle. In normal bitches, endometrial TGF-alpha mRNA levels were highest at proestrus and gradually decreased as the cycle progressed to anestrus. Epidermal growth factor receptor mRNA levels were not significantly affected by the stage of the estrous cycle. Epidermal growth factor mRNA levels were higher at Day 35 of diestrus than at other stages of the estrous cycle (P<0.05). In bitches with pyometra, endometrial TGF-alpha and EGF-R mRNA levels did not differ significantly from those at diestrus in normal bitches, but EGF mRNA levels were lower than those at Day 35 of diestrus in normal bitches (P<0.05). In normal bitches, positive immunohistochemical staining for TGF-alpha, EGF, and EGF-R was mainly present in the glandular and luminal epithelial cells of the endometrium. In contrast, in bitches with pyometra, immunoreactivity for EGF was clearly present in endometrial stromal cells. Inflammatory cells that had infiltrated the endometrial stroma stained strongly for TGF-alpha and EGF-R. Luminal and glandular epithelial cells also stained positive for EGF-R. In conclusion, expression of TGF-alpha by inflammatory cells and a low level of expression and differential localization of EGF may be involved in aberrant growth of endometrial glands and development of CEH.

Naturally Occurring and Melengestrol Acetate-associated Reproductive Tract Lesions in Zoo Canids

As husbandry practices have improved, safe and effective contraception for captive wildlife management has become a necessity. Melengestrol acetate (MGA), a synthetic progestin, is highly effective and has been used in many zoo species. Long-term use of MGA has been associated with uterine lesions in zoo felids, but effects in zoo canids have not been evaluated. This retrospective study documented spontaneously occurring lesions and investigated the impact of MGA on the reproductive health of zoo canids. Reproductive tracts from adult females were submitted by US zoos to the Association of Zoos & Aquariums' Wildlife Contraception Center Health Surveillance Program. Reproductive tracts were sampled and processed for histopathologic examination following standard protocols. Microscopic evaluations were performed without prior knowledge of MGA treatment status. Prevalence of uterine lesions was evaluated and compared between MGA-treated animals (n = 20) and control (untreated) animals (n = 61). Common lesions within the study population as a whole included endometrial hyperplasia (predominantly cystic) (53%), hydrometra (33%), and adenomyosis (25%). Treatment with MGA was a risk factor for endometrial hyperplasia, hydrometra, fibrosis, and adenomyosis. Uterine mineralization occurred exclusively in MGA-treated animals. Results indicate that MGA contraception can lead to lesions that may permanently impair the fertility of females. Therefore, if long-term contraception of zoo canids is necessary, the use of alternate methods of reproductive control such as gonadotropin-releasing hormone (GnRH) analogs or GnRH vaccines that reduce gonadal hormone exposure should be pursued.

Mucometra, cystic endometrial hyperplasia, and pyometra in the bitch: advances in treatment and assessment of future reproductive success

Pyometra is a common reproductive disorder which affects nearly one fourth of all female dogs before they reach 10 y of age. An association between pyometra and the most common uterine disease of the bitch, cystic endometrial hyperplasia, has been established, as the latter allows commensal bacteria originating from the vagina to proliferate in the uterus at the end of estrus. The progressive degenerative process in the development of cystic endometrial hyperplasia is usually proposed as the initiating lesion for pyometra in bitches; this is mediated by progesterone and potentially aggravated by estrogens. However, a separate process caused by local uterine irritation to trophoblastic reaction and bacterial proliferation has been recently proposed as an alternate mechanism leading to the development of pyometra. Pyometra is clinically distinct in pathogenesis, signs, treatment and prognosis from postpartum metritis or mucometra. Treatment of pyometra has historically involved ovariohysterectomy, however, during the last 10 y, numerous effective treatments have been proposed to treat both open and closed cervix pyometra with good success and future fertility. Among the treatments available, the use of repeated low doses of prostaglandins alone or in association with either dopamine agonists or progesterone-receptor antagonists has been demonstrated to be a viable alternative for valuable breeding dogs.

Hysterectomy leads to fast improvement of haematological and immunological parameters in bitches with pyometra

OBJECTIVES

To investigate whether a combination of hysterectomy and antibiotic treatment leads to an improvement of altered haematological and immunological parameters in bitches affected by pyometra.

METHODS

Blood samples obtained from 13 bitches affected by pyometra were investigated before hysterectomy and seven days later for a total and differential leucocyte count, activity of neutrophils and lymphocytes, and quantification of total serum immunoglobulins, lysozyme and circulating immune complexes.

RESULTS

The parameters most affected included changes in blood profile (leucocytosis because of neutrophilia or leucopenia) and inhibition of lymphocyte activity. Seven days after hysterectomy, all affected parameters returned to normal levels comparable to clinically healthy dogs.

CLINICAL SIGNIFICANCE

Application of immunostimulating therapy is not necessary to manage changes in blood cell counts and suppression of lymphocyte activity in bitches with pyometra. Removal of the infected uterus, being the source of infection, leads to improvement.

Role of progestin-induced mammary-derived growth hormone in the pathogenesis of cystic endometrial hyperplasia in the bitch

Endogenous progesterone and synthetic progestins may induce hypersecretion of growth hormone (GH) of mammary origin, hyperplastic ductular changes in the mammary gland, and the development of cystic endometrial hyperplasia (CEH) in dogs. It was investigated whether progestin-induced mammary GH plays a role in the pathogenesis of CEH in the bitch. During 1 year, bitches with surgically excised mammary glands and healthy control bitches received medroxyprogesterone acetate (MPA). Before and after MPA treatment, uterine and mammary tissues were collected for histological, immunohistochemical, and RT-PCR examination. After MPA administration, the mammary tissue in the control dogs had differentiated into lobulo-alveolar structures and CEH was present in all uteri of both dog groups. In the MPA-exposed mammary tissue of the control dogs, GH could only be demonstrated immunohistochemically in proliferating epithelium. After treatment with MPA the dogs of both groups had immunohistochemically demonstrable GH in the cytoplasm of hyperplastic glandular uterine epithelial cells. RT-PCR analysis of the mammary gland tissue after MPA administration demonstrated a significant higher GH gene, and lower GHR gene expression than before treatment. In the uterus, the expression of the gene encoding for GH was significantly increased in the mastectomized dogs, whereas in the control dogs the expression of the gene encoding for insulin-like growth factor-I had significantly increased with MPA administration. MPA treatment significantly down regulated PR gene expression in the uterus in both dog groups. These results indicate that progestin-induced GH of mammary origin is not an essential component in the development of CEH in the bitch.

Changes in CRP, SAA and haptoglobin produced in response to ovariohysterectomy in healthy bitches and those with pyometra

The aim of the study was to assess changes in serum C-reactive protein (CRP), serum amyloid A component (SAA) and haptoglobin (Hp) concentrations in healthy bitches and in those with pyometra undergoing ovariohysterectomy, and to establish the usefulness of such determinations for monitoring the postoperative period. Our results indicate that CRP and SAA determinations serve to evaluate the severity of the inflammatory process in pyometra since the concentrations of these acute phase proteins were increased immediately after surgery and diminished thereafter. The CRP and SAA response was rapidly produced while Hp concentrations increased in a more gradual manner. Thus, postoperative concentrations of CRP and SAA provide valuable information on the subsidence of the inflammatory response during the uneventful postoperative period. Our findings also suggest that acute phase proteins might be useful diagnostic markers of early postoperative complications.

Endometrial Polypoid Adenomyomatosis in a Bitch with Ovarian Granulosa Cell Tumour and Pyometra

Endometrial polypoid adenomyomatosis in an 8-year-old German shepherd bitch is described. The lesion was associated with ovarian granulosa cell tumour and pyometra; grossly, it consisted of sessile or pedunculated processes with both epithelial and non-epithelial components, in which smooth muscle cells were predominant. The endometrium was diffusely atrophic and showed multifocal squamous metaplasia. The findings are discussed as possible consequences of the functioning ovarian tumour and pyometra, but an involvement of growth factors is also proposed.

Ultrasonography and Cystic Hyperplasia-Pyometra Complex in the Bitch

Cystic endometrial hyperplasia-pyometra complex is the most frequent and important endometrial disorder encountered in bitches. The pathogenesis of the disease is related to the activity of progesterone [Feldman and Nelson, Canine and Feline Endocrinology and Reproduction (1996) W.B. Saunders, Philadelphia]. Cystic endometrial hyperplasia (CEH) is an abnormal response of the bitch's uterus to ovarian hormones [De Bosschere et al. Theriogenology (2001) 55, 1509]. CEH is considered by many authors to be an exaggerated response of the uterus to chronic progestational stimulation during the luteal phase of the oestrous cycle, causing an abnormal accumulation of fluid within the endometrial glands and uterine lumen (De Bosschere et al. 2001). The resulting lesions of pyometra are due to the interaction between bacteria and hormones. The aim of this study was to evaluate if transabdominal uterine ultrasonography can be a useful and reliable diagnostic method to confirm Dow's [Veterinary Record (1958) 70, 1102] and De Bosschere's histopathological classification of CEH-pyometra complex. The study was carried out on 45 bitches with pyometra, 10 purebreds and 35 crossbreeds, 1-15 years old, 20% of which had whelped at least once. None of these animals had received exogenous oestrogen or progesterone treatment. On admission the 45 animals were in the luteal phase of the oestrus cycle. Clinical signs, blood parameters, uterine ultrasonography, bacterial swabs and uterine histopathological results were recorded. Results suggest that ultrasonographic examination is a useful and reliable tool for the diagnosis of cystic endometrial hyperplasia.

Omentalization of a nonresectable uterine stump abscess in a dog

One month after ovariohysterectomy, a 2-year-old spayed female Golden Retriever was evaluated because of an extensive uterine stump abscess. Clinical signs included intermittent vomiting, signs of depression, lethargy, and pollakiuria. The dog underwent abdominal surgery; the greatly enlarged uterine stump was tightly adhered to the dorsal surface of the bladder, encompassing the distal portions of the ureters and the bladder's neurovascular supply. En bloc resection of the uterine stump was not considered an acceptable treatment option because of the risk of surgical damage to and subsequent devitalization of the bladder or ureters, urinary incontinence, or urinary tract obstruction. Therefore, the diseased uterine tissue that extended cranial to the bladder was resected, and the remaining abscess cavity was lavaged and packed with omentum. The dog recovered fully from the procedure. The omentum is an effective physiologic drain; its extensive vascular and lymphatic networks absorb fluid and actively promote elimination of infection. Omentalization appears to be an option for surgical management of nonresectable uterine stump abscesses in dogs.

Morphological changes of the endometrial epithelium in the bitch during metoestrus and anoestrus

Although cyclic changes of the endometrium in dogs involving both stromal and glandular compartments have been described, the fate of the surface epithelium after progressive growth and secretion is still unclear. In the present study, uteri of 43 healthy bitches in metoestrus and anoestrus were examined macroscopically and histologically. Tissue biopsies were taken from three different locations (cranial and middle parts of uterine horns and bifurcation). The stage of the oestrous cycle was determined by evaluation of progesterone and oestradiol levels in plasma hormone and was also confirmed clinically. Crypts formed in the luteal phase were covered with a columnar epithelium which gradually underwent fatty degeneration. In addition, the stromal part of the crypts disappeared and finally, in early anoestrus, epithelial sheaths desquamated and shed off into the uterine lumen. The surface epithelium was replaced by new cuboidal cells proliferating and migrating from the glandular openings. These findings were confirmed by oil red O staining and immunohistochemical detection of proliferation with Ki-67 marker.

Influence of reproductive status on in vitro oocyte maturation in dogs

In the bitch, oocytes need 48-72 h to complete post-ovulatory maturation to the metaphase II stage in the isthmus of the oviduct, an interval similar to that found in in vitro studies. The effect of estrous cycle stage on in vitro meiotic competence of dog oocytes has been described in several studies. However, there are no reports evaluating the possible effects of pyometra or pregnancy on subsequent potential of oocytes recovered from such females to undergo in vitro maturation. In this study, immature cumulus-oocyte complexes (COCs) were recovered from fresh excised domestic dog ovaries in various reproductive states. The donor females were classified into groups based on stage of the estrous cycle: follicular (proestrus or estrus), luteal (diestrus) or anestrus or at the clinical conditions of pregnancy and pyometra. Grades 1 and 2 oocytes were cultured in vitro at 37 degrees C in TCM-199, supplemented with 25 mM Hepes/l (v/v), and with 10% heat inactived estrous cow serum (ECS), 50 microg/ml gentamicin, 2.2 mg/ml sodium carbonate, 22 microg/ml pyruvic acid, 1.0 microg/ml estradiol, 0.5 microg/ml FSH and 0.03 IU/ml hCG. The nuclear maturation rate was evaluated at 72 h of incubation under Hoechst 33342 (10 microg/ml) staining for fluorescence microscopy. There was no statistical difference in nuclear progression to the MII stage among the various reproductive states (follicular phase, 5.4%; diestrus, 4.2%; anestrus, 4.4%; pyometra, 8.1% and pregnancy, 4.7%). Resumption of meiosis was 24.6% at the follicular phase, 19.6% for diestrus, 16.4% for anestrus, 37.1% for pyometra and 29.2% for pregnancy. Positive and higher numbers of residue above the expected value were observed for the pyometra and pregnancy conditions at the metaphase/anaphase I (MI/AI) stages.Our results indicate that in vitro nuclear maturation of dogs oocytes is not influenced by the in vivo reproductive status of the female. The quality of the oocyte is a more reliable indicator of its potential for meiotic maturation in vitro than the hormonal environment of the donor female at the time of oocyte retrieval.

Changes in sex hormone receptors during administration of progesterone to prevent estrus in the bitch

The development of lesions and the changes in sex hormone receptors were studied in the uteri of bitches under progesterone treatment. Twelve weeks after the onset of treatment, there was atrophy of the endometrium and increased thickness of the myometrium, without cystic dilatation of endometrial glands. This was accompanied by a dramatic reduction in estrogen-alpha and progesterone receptors in all cell types of the uterine wall. By 24 weeks after the onset of treatment, however, the endometrium was thickened due to the development of cysts of endometrial glands, while the myometrium thickness had returned to normal. The estrogen-alpha and progesterone receptors in most cell types of the uterine wall were again within the normal range. These results clarify and reconcile some apparent contradictions in the literature. They show that sex hormone receptors in most cell types of the uterine wall, especially endometrial gland cells and stromal cells, escape progestin (down) regulation after prolonged exogenous administration of progesterone.

Possible role for insulin-like growth factor-I in the pathogenesis of cystic endometrial hyperplasia pyometra complex in the bitch

Cystic endometrial hyperplasia (CEH) is an important pathologic condition in the canine uterus and recognized as a common cause of illness and death in this species. The underlying cause and pathogenic mechanism responsible for this condition remains incompletely understood. Aberrant sex steroid hormone receptor expression in the uterus of dogs with CEH has been documented but not explained. In the dog there is an exceptionally high, progestin induced production of insulin-like growth factor-I (IGF-I) which is now generally accepted to be one of the most important growth factors with a high mitogenic effect on the uterus. Therefore, in this study the immunohistochemical staining intensity for IGF-I was compared among the uteri of 25 adult female dogs that had developed CEH and 14 healthy dogs in comparable stages of the estrus cycle. Specific staining for IGF-I was found in the cytoplasm epithelial cells and in smooth muscle cells of endometrium and myometrium. A marked increase in specific staining intensity for IGF-I was found in the surface epithelium, glandular epithelium and in the stroma of the uteri of dogs with CEH. The increase in IGF-I specific staining intensity was most prominent in the superficial endometrial stroma. Based on the known role of IGF-I in endometrial proliferation, it was concluded from the present study that high concentrations of IGF-I located in and around the epithelial cells of the endometrium in dogs with CEH, could play an important role in the development of CEH.

Estrogen-alpha and progesterone receptor expression in cystic endometrial hyperplasia and pyometra in the bitch

Estrogen-alpha receptor (ER) and progesterone receptor (PR) were examined immunohistochemically in uteri of normal bitches, in uteri of bitches with cystic endometrial hyperplasia-mucometra (CEH-M) and in uteri of bitches with endometritis-pyometra (E-P), under exogenous progesterone treatment. In the CEH-M group, the ER- and PR-scores of all uterine cell types were higher than the ER- and PR-scores of normal uteri, although these differences were not always statistically significant. The ER-scores of E-P group were significantly lower than the ER-scores of the normal uteri and CEH-M group. The PR-scores of the E-P group tended to be higher than the PR-scores of the normal uteri, except for the surface epithelium, although these differences were not statistically significant. Exogenous progesterone treated bitches with CEH-M or E-P showed reduced ER- and PR-scores in the different uterine cell types, compared with the corresponding nontreated CEH-M or E-P group. The differences in ER and PR expression between CEH-M and E-P suggest different factors in the pathogenesis of both entities. Although, these changes in ER and PR expression do not seem to be directly involved in the pathogenesis of CEH-M and E-P. It is suggested that for CEH-M and progestin induced CEH-M a hormone dependent pathway is responsible. For P, the trigger may be bacterial infection.