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Spay And Neuter

Why and when to spay and neuter our pets.

I’ve been writing monthly articles for a while now and the topic often comes from something that happens in my day-to-day practice. This particular subject is something I discuss on a daily basis, and when a good client with a new golden retriever puppy recently and asked some very good questions it made me examine current recommendations regarding spaying and neutering more closely. Not just if we should, but also the timing of the procedure.

Of course, the main purpose of spaying and neutering our pets is to control the pet populations. Millions of dogs and cats are euthanized annually in shelters because of pet overpopulation. However, that number has reduced over the years because of the focus on controlling reproduction in our pets. Prevention of certain medical and behavioral problems is another reason spaying and neutering are often recommended.

This year marks 25 years since I graduated from vet school, at that time it was standard to recommend 6 months of age to spay and neuter pets. My associates, who graduated more recently, were also taught to make the same recommendation. Years ago shelters moved to spay and neutering pets prior to adoption, performing surgery on puppies and kittens 7-8 weeks of age. This takes away the problem of the adopting family forgetting to bring back their pet for surgery and has been no small part of the success in decreasing the number of unwanted pets needing to be euthanized.

After spending hours reviewing research articles, opinion papers and discussions on an online veterinary forum, I can say there is no perfect answer, however, there is some compelling evidence worth considering when making recommendations. In the space of this article there isn’t enough room to go completely into all the information I went through, but I will do my best to synopsize what I feel are important points for both sexes of dogs and cats, placing emphasis on the more common conditions affected by altering (removing the reproductive organs.)

For female cats and dogs there a major reason to spay before the first heat than any other disease that may be increased from spaying is going to be a far second. The risk for mammary cancer decreases drastically if the pet is spayed prior to its first heat cycle. Most pets start to come into heat between 5 and 9 months of age. Pyometra, or infection of the uterus, is a very serious condition and the risk increases as the female dog ages. Of course, if she has had her reproductive organs removed, there is no risk.

Hormonal influence from the reproductive organs has been shown to have an effect on growth plate closure, which means when you remove the reproductive organs it takes longer for the growth plates to close. This leads to the pet having longer legs and being taller than it’s intact counterpart. This also has further orthopedic implications. Male cats that are neutered at a young age have been found to be more prone to fracturing the femur at the growth plate closest to the hip joint. In addition, frequency and/or severity of hip dysplasia and cruciate injuries in dogs can be influenced by the delayed growth plate closure. It is important to remember that all orthopedic diseases have multiple factors influencing the severity of the disease, including genetics, breed, diet, environment, activity, and weight.

Certain types of cancer can be affected by the removal of the reproductive organs. Osteosarcoma and hemangioma are two tumor types that have been examined. And have been shown to be more common in altered pets. These types of cancer are seen in larger breeds of dogs and may influence the decision to alter large breed dogs. Prostatic disease, a fairly common problem, is decreased by altering. Prostatic cancer, a much rarer condition, is increased by altering.

The information I was able to find clearly still reports the benefit of spaying female animals prior to their first heat cycle still outweighs other risks, so my recommendation will stay the same. Male cats have behavioral concerns that outweigh most medical concerns and neutering them before they reach puberty I feel is still a valid recommendation. Male dogs will take more consideration, taking into account the breed, genetics and lifestyle will help me make my recommendation.

I realize I have only touched a few important points in this discussion, if you have any further questions, please feel free to contact me at, or call me at Wilderness Animal Hospital, 425-432-9975. Don’t forget to like us on Facebook.