Cat Milk and Senior Cats

[Ani-Mei]

I just got here today and have a question, my 17 year old cat is sick and he's stopped eating. He has a tumour in his nasal cavity that is making him not eat. We've been to the vet's several times even taken him to an emergency hospital. He wasn't drinking either until today, I got him to drink some water. The vets said he needs to be able to smell to eat but not to drink, if he's just starting to drink again can he survive on cat milk if he can't eat solid food. The surgery to get rid of the tumour will most likely kill him in his weakened state right now and if he can start to take liquid food like the milk could it help him gain his strength back? Our other option is euthanasia and we don't want to do that if he can still be saved.