Two new studies suggest that early-age spay/neuter does not lead to greater risk of obesity or urinary incontinence than sterilization done when the pet is older.

“Effect of age at gonadectomy on the probability of dogs becoming overweight,” published in the July 2013 issue of the Journal of the American Veterinary Medical Association (JAVMA), concludes:

Gonadectomized dogs had a greater risk of being overweight than did sexually intact dogs, but this risk was not influenced by age at gonadectomy. Opportunities exist for veterinarians to provide counseling during the first years after gonadectomy to help dogs maintain a healthy weight.

The second study, “Evaluation of the prevalence of urinary incontinence in spayed female dogs,” also published in the July 2013 issue of JAVMA, concludes, "Although acquired urinary incontinence in female dogs is known to be associated with ovariohysterectomy, the prevalence in this study was low."

Forsee KM, et al. Evaluation of the prevalence of urinary incontinence in spayed female dogs: 566 cases (2003-2008), Journal of the American Veterinary Medical Association. 2013 Apr 1;242(7):959-62. doi: 10.2460/javma.242.7.959.

Lefebvre SL, Yang M, et al. Effect of age at gonadectomy on the probability of dogs becoming overweight. Journal of the American Veterinary Medical Association, 2013 Jul 15;243(2):236-43. doi: 10.2460/javma.243.2.236.