Veterinarians debate impact of spay/neuter

Older black dog outdoors in nature

Recent publications by researchers at the University of California, Davis on the risks to dogs of joint disorders, cancers, and incontinence following spay or neuter have spurred renewed debate about sterilizing dogs, as covered by the Veterinary Information Network (VIN) News ServiceSpay and neuter (known as gonadectomy, or removal of the reproductive tissues) is common practice in the U.S., Australia, and some European countries as a method to reduce pet overpopulation. However, gonadectomy effectively removes natural hormones for the life of the dog, and — not surprisingly — can result in a number of serious ailments.

The recent studies by Hart and colleagues evaluated 35 dog breeds as well as mixed-breed dogs for joint disorders like hip dysplasia, various cancers, and urinary incontinence, and compared the occurrence of these problems in spayed and neutered dogs to the occurrence in intact dogs. These studies provide guidance for pet owners and veterinarians about when — and if — dogs should be spayed or neutered.

Smaller dogs are likelier to be done growing when spayed or neutered at a young age, and therefore suffer fewer joint disorders than large-breed, slow-growing dogs that are spayed or neutered when young. However, Boston terriers and shih tzus have a high incidence of cancer following gonadectomy. And the authors recommend not spaying or neutering male Dobermans and female Golden retrievers due to the risk of cancer.

Questioning the value and applicability of traditional spay and neuter tends to arouse controversy. Thoughtful discussion and inquiry is appropriate whenever major shifts in treatment are considered. We applaud researchers for continuing to investigate the influence of the loss of natural hormones on pet health, and we appreciate online forums for offering an opportunity for debate and discussion.

What appears to be missing from much of the debate regarding whether and when to sterilize dogs is the fact that a simple alternative option exists: hormone-sparing sterilization. Vasectomy and hysterectomy are options that preserve protective hormones, but maintain population control. Including such hormone-sparing sterilization methods among the options available to pet owners helps them protect the long-term health of their dogs and tailor the right solution to the individual pet.

For more information on gonadectomy and hormone-sparing sterilization options, see our webpage on Hormone-Sparing Sterilization.