Second collaboration between ACC&D and Mars Veterinary Health yields new data on overweight and obesity risk in 15 popular U.S. dog breeds
Ann Arbor, Michigan (June 20, 2025): Research supporting healthy weight outcomes in dogs has grown with the publication of “Gonadectomy status and age are associated with variable risk of overweight or obese outcomes in 15 dog breeds: a retrospective cohort study using data from primary care veterinary clinics” in the Journal of the American Veterinary Medical Association.
The peer-reviewed paper is a collaboration between Mars Veterinary Health, including Banfield Pet Hospital, and a multidisciplinary expert team convened by the Alliance for Contraception in Cats & Dogs.
Authors analyzed anonymized data of over 116,000 dogs seen at Banfield in 2013-2019 to study the relationship between sterilization and overweight or obese (OvOb) outcomes. The present paper investigates 5 popular large breeds and 10 popular toy/small breeds: Labrador Retriever, German Shepherd, Boxer, Golden Retriever, American Bulldog, Yorkshire Terrier, Chihuahua, Shih Tzu, Maltese, Poodle, Pomeranian, Dachshund, Miniature Schnauzer, Pug, and Bichon Frise.
Key findings include:
There is substantial breed variation in underlying OvOb rates for intact dogs; Pugs, Golden Retrievers, and Labrador Retrievers had the highest underlying susceptibility.
There was some variation in relative OvOb rates among breeds following sterilization, but breeds differing substantially from size group peers were limited.
Among toy/small breeds, the relative OvOb risk among dogs sterilized before puberty was no higher than for dogs sterilized at 1 year of age or older. For large dogs, OvOb outcomes associated with prepubertal sterilization varied by breed.
“Dogs in certain regions, including the U.S., regularly experience serious overweight and obesity challenges, with potentially significant consequences for their well-being and health,” explains Dr. JoAnn Morrison, Director of Global Veterinary Science and Health Outcomes at Mars Veterinary Health, and a study coauthor. “In a previous study with ACC&D, we examined OvOb risk following sterilization in different sizes of dogs, and the small and large breed groups had unexpected outcomes. This warranted deeper research into the factors driving these results.” The first publication is available here.
Valerie Benka, Program Consultant for the Alliance for Contraception in Cats & Dogs, shares, “Sterilization offers clear health and welfare benefits at the individual and population levels for dogs, and increased risk of obesity shouldn’t be a reason to avoid surgery. Rather, these findings can help veterinarians and dog owners to be especially attuned to breed-level obesity risks and proactive about mitigation strategies.” Human behaviors are known to strongly influence dog OvOb outcomes through feeding practices and physical activity.
More details are available in the Mars Veterinary Health press release. Contributors to the research represent the Alliance for Contraception in Cats & Dogs; Mars Veterinary Health, including Banfield; Virginia-Maryland College of Veterinary Medicine Department of Population Health Sciences; Jonsson Comprehensive Cancer Center, University of California, Los Angeles; Hunter College Program in Animal Behavior and Conservation; and University of Padova Department of Animal Medicine, Production and Health.
ACC&D is a nonprofit organization whose mission is to advance non-surgical sterilants and contraceptives for cats and dogs and to promote their global accessibility. For more information visit www.acc-d.org.
Contact: Valerie Benka, Program Consultant, ACC&D, valerie@acc-d.org
The study and open-access publication are made possible through a grant from Morris Animal Foundation (Grant ID D22CA-513).