When I was going through vet school, the mantra was “let them have a heat (or even a litter) before spaying.”
For males, the thinking was that they needed to be at least 8 months old before being neutered so the urethra would be mature enough to prevent urinary blockages. Of course, the latter statement did not make sense to me as plenty of intact adult male cats suffer from urethral blockages.
As early as 1996, research funded in part by EveryCat Health Foundation had proven that early spay/neuter is safe and effective.
Kittens can safely be spayed or neutered as early as 10-12 weeks of age. For me and most of the high volume spay/neuter clinics I’m aware of, the cutoff is not age but weight. I like the kittens to be 1 kilogram or about 2 pounds for surgery. My exception is males with one or both retained testicles. I like for these boys to be a little bigger before operating on them.
Safe and effective intramuscular anesthetic injections are part of the reason for this shift. While many breeders have heard that the injectable anesthetic ketamine is not safe for use in some breeds, I have not seen any published documentation of this fact. Most high-volume clinics use a mixture of ketamine, butorphanol, and dexmedetomidine commonly known among veterinary professionals as “kitty magic”. At low doses it provides enough sedation for the kittens to be fully anesthetized with gas through a mask. At higher doses it is sufficient anesthesia for the procedures in most cases. It may or may not be partially reversed with another drug, depending on the doctor’s usual protocol. Either way the kittens wake up quickly-in as short a time as 15 minutes. Some doctors add an injection of a non-steroidal anti-inflammatory drug for pain, but in my experience, I find the remaining butorphanol narcotic provides adequate pain relief. I have operated on all the kittens I sold as pets over the last several years, so I can attest that the kittens do not act as if they even know they have had surgery after they go home.
Several studies have shown that there are no adverse effects in cats due to prepubertal spay or neuter. Benefits include faster surgery with less surgical complications than surgery performed on adult cats; prevention of mammary tumors in mature females; prevention of most unwanted behavior issues, such as spraying, in male cats; and most importantly, the prevention with absolute certainty of unwanted litters of kittens.
While not all veterinarians have jumped on the band wagon that is early spay/neuter, it is usually possible to find a HQHVSN (high quality high volume spay neuter clinic) in most metropolitan areas. Many of them have the added benefit of being lower cost due to the volume of surgeries performed in a day.
Many breeders and nearly all rescue groups prefer to have kittens altered before they go their new homes. Studies have shown that animals adopted intact from a shelter or animal control often do not get fixed in a timely manner, even when the adopters are subject to fines if they don’t comply with the required procedures. No matter where you obtain your kitten, if it did not come to you already altered, make arrangements to get him or her altered before six months of age. –Dr. Thomas
Karen Thomas, DVM is a 1970 graduate of Michigan State University. She is the founder and owner of Three Counties Animal Hospital in Georgia, but retired after 40 years in private practice to operate Rescuevet Services, a non profit clinic devoted to providing veterinary services to local rescue groups and humane societies. Since starting Rescuevet Services, she has performed over two thousand spays and neuters each year.