New study looks at intratesticular injections for neutering cats.

Veterinarians in Brazil have released a study that looks at the effectiveness of using zinc gluconate injections in the testicles of cats as a replacement for neutering.  You can read the study abstract here.

Zinc gluconate has been used in dogs as an alternative to surgical neutering.  I previously wrote about the pros and cons of zinc gluconate for neutering dogs.  In my opinion there is a place for this type of product in veterinary medicine, but because of the potential side effects I would be reluctant to recommend it for my clients’ pets.  Where it could be used, however, is in shelters or in remote communities with a pet overpopulation problem.  So, could a similar product for cats be effective?

How does zinc gluconate work to chemically neuter a pet?

The product is injected into the testicles.  According to manufacturers of different types of zinc gluconate made for dogs, the injections can usually be done with either mild sedation, or in the hands of a vet who has experience with this product, even no sedation.  I am not sure whether the same is true for cats.  I would imagine that some type of sedation would be necessary though.  The product causes the testicle to not be able to produce sperm and in most cases in dogs is permanent.

The results of the study.

The study was performed on 16 cats which is, in my opinion, not enough cats to let us draw conclusions. 11 cats had their testicles injected with zinc gluconate and 5 had saline injections.  They looked at the cats 120 days later and found that 8/11 had no sperm, 6/11 had fewer penile spines and 4/11 had no penile spines.  (Penile spines are only there in the presence of testosterone.  When a cat has been surgically neutered, these spines will totally disappear.)  Blood tests showed that there was no difference in the testosterone levels of cats that had been given the zinc gluconate injections vs the saline injections.

These results do not sound very positive to me.  It sounds like the drug had some type of effect but not the full effect desired.  Also, the study did not mention the severity of side effects after these injections.

Given that a cat neuter is a very simple and quick procedure that can be done with injectable sedation alone, at this point I don’t see much benefit to using zinc gulconate.