No Reason to Delay

 Philip A. Bushby, DVM, MS, DACVS

 A client walks into the veterinarian’s office with a new kitten.  One of the most common questions that client will ask is “When should I have my cat spayed (or neutered, if it is a male)? 

 Should the answer to that question be based on opinion or our scientific evidence?  Should the answer to that question vary from one veterinary clinic to the next, or should it be consistent? 

Until now the profession has not been able to come to an agreement on the appropriate age for spay and neuter of cats.  This has led to a considerable amount of confusion with many in the public not knowing when to schedule the surgeries.  Unfortunately, this confusion has consequences.  We see the consequence when we walk into animal shelters and see them overrun with kittens. 

Glen Olah, DVM Ph.D. DABVP and president of the Winn  Feline Foundation has stated; “No wonder clients are often confused, or simply put spay/neuter off.  If we’re the experts we should offer a clear direction to cat owners.

Thanks to the work of the Veterinary Task Force on Feline Sterilization, we now can offer clear direction to cat owners. 

A comprehensive review of the veterinary literature regarding spay / neuter in cats revealed:

  • Ovariohysterectomy prior to the first heat cycle has a protective affect against mammary neoplasia.  Given that cats can come into heat by five months of age and that 90%  of mammary tumors in cats are malignant.  Spay / neuter prior to five months of age is critical.

  • No evidence that spay / neuter prior to five months of age is linked to increases in any disease or orthopedic conditions. 

Given these facts, why is there still confusion?  Why is there still disagreement?

There has been more research on the effects of spay / neuter in dogs and there are some adverse consequences of spay / neuter especially in some large breed dogs.  Some veterinarians simply assume that what is true in some dogs must be true in cats as well, but that is not necessarily the case.

In an effort to bring some consistency to the recommendations for feline spay / neuter the Veterinary Task Force on Feline Sterilization developed a consensus statement – found here.  The document states, in part;

 “Given the known benefits of sterilization and the lack of evidence for harm related to age at which the procedure is performed, the Veterinary Task Force on Feline Sterilization calls for veterinary practitioners and professional associations to recommend sterilization of cats by 5 months of age. This provides veterinary practitioners with a consistent message that may increase veterinary visits and spay/neuter compliance while reducing the risk of pet relinquishment and unwanted offspring.”

Since the Veterinary Task Force on Feline Sterilization published their consensus statement on Recommendations for Age of Spay and Neuter Surgery it has been officially endorsed by the AVMA, AAHA, AAFP, ASV and numerous humane organizations.  The message is this: if all practicing veterinarians were to change the age at which they spay and neuter cats to before 5 months of age the overpopulation of cats would, over time, simply disappear. 

The profession has spoken.  The major professional veterinary organizations are in agreement.  But still some veterinarians resist.  There are three basic reasons why some veterinarians are still recommending 6 months or even older for sterilization of cats.

  1. It  is a change and it is natural for people to resist change.

  2. Many veterinarians have not heard of Feline Fix by Five (FFF) or the endorsements by professional and humane organizations.  A series of surveys in multiple states revealed that approximately ¾ of the responding veterinarians were not aware of FFF or of the endorsements by professional associations.  The good news was that ¾ of the responding veterinarians stated that now that they were aware they would change.

  3. There are some theories related to adverse effects that are persistent myths. Some fear that earlier feline neuter may predispose to urinary obstruction.  But there is no scientific basis for that fear.  Others fear that earlier spay / neuter may predispose to slipped capital epiphysis. Again, there is no scientific basis for that fear either.

A comprehensive search of the veterinary literature reveals no proven adverse effects from reducing the age of spay/neuter of cats from 6 months to 5 months or younger and numerous benefits.  Spay / neuter by 5 months of age will eliminate unwanted pregnancies and will significantly reduce the incidence of mammary neoplasia in cats.  Couple this with the fact that the surgeries are easier and faster, the recoveries are faster, and the incidence of anesthetic and surgical complications is lower there is no reason to delay spay/neuter of cats past 5 months of age!

The profession has an answer.  Spay / neuter of cats by 5 months of age.  The evidence is in, there is no reason to oppose.