Assessment of reported uterine lesions diagnosed histologically after ovariohysterectomy in 1,928 pet rabbits (Oryctolagus cuniculus).

OBJECTIVE: To assess variations in age, breed, and clinical signs in rabbits with neoplastic or nonneoplastic uterine lesions and to investigate potential relationships between endometrial adenocarcinoma and age at ovariohysterectomy or breed in rabbits. ANIMALS: 1,928 rabbits that underwent ovariohysterectomy for treatment or prevention of possible uterine disease. PROCEDURES: With an online questionnaire distributed to 441 veterinary hospital members of the Japanese Society of Exotic Pet Medicine, data were retrospectively collected regarding age, breed, and findings on physical and histologic examinations for pet rabbits that underwent ovariohysterectomy between January 1, 2009, and April 30, 2018. Rabbits were grouped by reported age, breed, clinical signs, and uterine lesions, and results were assessed across groups. Logistic regression analysis was used to identify potential relationships between endometrial adenocarcinoma and breed or age at ovariohysterectomy in rabbits. RESULTS: The questionnaire response rate was 9.8% (43/441), with data reported for 1,928 rabbits (mixed breed, 600 [31.1%]; Netherland Dwarf, 520 [27.0%]; Holland Lop, 286 [14.8%]; or various other breeds, 522 [27.1%]). The most commonly reported neoplastic and nonneoplastic lesions were endometrial adenocarcinoma (1,035/1,928 [53.7%]) and endometrial hyperplasia (842 [43.7%]), respectively, and the most commonly reported clinical sign was hematuria or serosanguineous vaginal discharge (1,020/1,928 [52.9%]). As age at ovariohysterectomy increased, so did the odds (OR, 1.826; 95% CI, 1.640 to 2.033) of uterine adenocarcinoma. CONCLUSIONS AND CLINICAL RELEVANCE: Results supported ovariohysterectomy in rabbits before 2 years of age as a key preventative measure to mitigate uterine disease, particularly endometrial adenocarcinoma.

Assessment of the optimal age for a preventive ultrasonographic screening of the uterine health in bitches.

Studies about prevalence of uterine pathologies in bitches are scarce. Although correlation between age and uterine disorders was documented, the most suitable age for a preventive sonographic screening has not been proposed yet. Present study aimed to estimate the eligible age for an ultrasonographic screening of uterine abnormalities in dogs. Data regarding ultrasound examination and clinical records of non-pregnant intact females were retrospectively analysed. The age of each bitch was expressed as age ratio (actual/maximum age expected for the respective breed). The cut-off age ratio was determined by a ROC curve for overall uterine abnormalities. Frequencies of different abnormalities below and over the cut-off derived from the ROC curve were calculated and statistically analysed by chi-Square and OR. Prevalence of three categories of ultrasonographic findings was as follows: cystic endometrial hyperplasia (CEH) 18%; uterine collections (UC) 10.5%; masses (M) 1.3%. By the cut-off age ratio (0.325), derived by ROC curve (AUC = 0.91; SP 84.23%; SE 79.2%; PPV 83.4%; NPV 80%), 228 cases were divided into two subgroups: bitches over (exposed group: n.83) and below cut-off (control group: n.145). All abnormalities resulted more frequent in exposed group: OR was 24.96 (p < 0.0001: 71.1% over vs. 9% below cut-off) for overall abnormalities; 13.68 (p < 0.0001: 40.9% vs. 4.8%) for CEH; 6.13 (p < 0.002: 21.7% vs. 4.1%) for UC; 12.65 (p = 0.09: 3.6% vs. 0%) for M. Cystic endometrial hyperplasia represents the most common finding in adult bitches, followed by UC. A preventive sonographic screening for uterine abnormalities should start from 33% of expected longevity to preventively select animals requiring further evaluations.