Would acyclovir for cats work to treat feline tumors?

Original Question: My cat Goofy had a tumor taken off his back. The incision has not healed well and could not be fully closed by the veterinarian. He has tolerated this open wound very well. He allows me to spray it with Chlorhexidine. His demeanor is excellent. No infection. However new tumors are beginning to grow in area. I know this is probably not going to turn out well. There is a cream called Acyclovir cream used for herpes. My vet and I researched it for my horse after he had nasty sarcoid removed. I have been applying daily to my horse and so far after almost 8 months there is no sarcoid return. It had returned before. My question is can I use it on goofy. The only thing I wonder is if he licks it. He has left the site alone as it is difficult for him to reach. The Acyclovir is also known as Zovirax. - Shannon and Goofy

Mar 1, 2018

Hi Shannon,

Sorry to hear this about the tumors returning. I don’t think that technically Acyclovir for cats would help with this but I’m saying that because I don’t think it’s been researched. I suppose there’s no harm so you could go ahead but I don’t have the medical evidence to think that it would be beneficial. I found some posts in the research that suggest it may help with the discomfort that cancer brings but this is based on a single case only, it really means we have no evidence. The fact that it is an anti-viral drug, it should really not have any effect on a cancer.

My advice is to find a veterinary oncologist and go for at least an initial appointment. I would do this as soon as you can. They’ll give you a wealth of information even in the first appointment that would really educate you on your options. I STRONGLY recommend this.