Data analysis of these records provided striking results. Sterilized dogs had a significantly higher risk of atopic dermatitis, autoimmune hemolytic anemia, hypoadrenocorticism, hypothyroidism, immune-related thrombocytopenia, and inflammatory bowel disease than intact dogs. Sterilized female dogs had an even greater risk than neutered males for almost all immune diseases analyzed in the study. Further, sterilized females (but not males) had a significantly greater risk of lupus erythematosus than intact females. Expectedly, pyometra (secondary infection of the uterus) was a greater risk for intact females.
The study’s authors concluded that the findings underscore the importance of sex hormones on canine immune function. In recognizing that sterilization procedures provide value—including for population control, reduction of reproductive disorders, and convenience for owners—the authors propose that their analyses suggest that spaying and neutering is associated with increased risk for certain autoimmune disorders, and underscores the need for owners to consult with their veterinarians prior to spaying or neutering to evaluate possible benefits, risks, and alternatives associated with those procedures. Additionally, the authors qualify that while their findings indicate a significant risk associated with canine sterilization procedures and disease, they do not indicate causality. They propose that additional prospective studies be conducted to confirm the relationship of sex steroids and autoimmune risk.
The American Kennel Club promotes a balanced approach to the issues surrounding spaying and neutering. We encourage pet owners to spay or neuter their dogs as a responsible means to prevent accidental breedings that result in unwanted puppies. However, the AKC opposes laws that mandate the spaying or neutering of purebred dogs. Ultimately, we believe that all health care decisions, including whether to spay or neuter, should be made by a dog’s owner in consultation with their veterinarian. This latest report provides further evidence that gonadectomy, like other major surgical procedures, should not be entered into without consideration of long-term health impacts and never be arbitrarily mandated by a government entity.
The research article may be viewed at http://bmcvetres.biomedcentral.com/articles/10.1186/s12917-016-0911-5.