Epidemiology of mammary tumours in bitches under veterinary care in the UK in 2016

Varney, Danielle; O'Neill, Dan; O'Neill, Maeve; Church, D; Stell, Anneliese; Beck, Sam; Smalley, Matthew J.; Brodbelt, D

Abstract

BackgroundThere is limited information on the epidemiology of canine mammary tumours. This study aimed to estimate the incidence and risk factors for mammary tumours in UK bitches. MethodsA nested case-control study was conducted within VetCompass to estimate the frequency and risk factors for clinically diagnosed mammary tumours during 2016 (VetCompass study). A second case-control study explored further breed associations for cases confirmed histopathologically compared to the VetCompass controls (laboratory study). Multivariable logistic regression was used to evaluate associations between risk factors and mammary tumours. ResultsThe incidence of mammary tumours was 1340.7/100,000 per year (95% confidence interval: 1198.1-1483.3). A total of 222 clinical cases (VetCompass study) and 915 laboratory cases (laboratory study) were compared to 1515 VetCompass controls in the two analyses. In the VetCompass study, Springer and Cocker Spaniels, Boxers, Staffordshire Bull Terriers and Lhasa Apsos had increased odds of developing mammary tumours. Neutering was associated with reduced odds, while odds increased with increasing age and a history of pseudopregnancy. In the laboratory study, increasing age was associated with greater odds of mammary tumours, and the breeds most at risk were similar to those identified in the VetCompass study. LimitationsThe timing of neutering was not consistently available. Comparing laboratory cases to VetCompass controls provided only exploratory evidence for the breed associations identified. ConclusionsThe study provides an update on the frequency of canine mammary tumours.

Citation

Varney, D., Varney, D., O'Neill, D., O'Neill, D., O'Neill, M., O'Neill, M., …Brodbelt, D. (2023). Epidemiology of mammary tumours in bitches under veterinary care in the UK in 2016. Veterinary Record, https://doi.org/10.1002/vetr.3054

• Journal Article Type: Article
• Acceptance Date: Apr 25, 2023
• Online Publication Date: May 25, 2023
• Publication Date: 2023
• Deposit Date: May 31, 2023
• Publicly Available Date: Jun 7, 2023
• Journal: Veterinary Record
• Print ISSN: 0042-4900
• Electronic ISSN: 2042-7670
• Publisher: BMJ Publishing Group
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1002/vetr.3054
• Keywords: CANINE NEOPLASIA; FEMALE DOGS; BRCA1; EXPRESSION; SURVIVAL; POPULATION; RISK