As mentioned by others giving a medication that is not prescribed by your vet is not a good idea. Even though it is a broad spectrum antibiotic and can be used for uti's, it can react negativily with other medications that your cat may be on. Also as stated unless you have a scale for measuring there is no accurate way to guarentee the exact amount that is being given. When it comes to pharmacuticles things can get very complicated. If you already have the amoxicillin than I would give it to Sammy as directed.
It is good that Sammy is drinking. Since he seems to like running water, you might want to consider buying a water fountain for him to help to encourage him to drink water as he is getting over everything that has been going on now, and also to help to promote him and your other cats to drink when everyone is healthy.
For eating, not sure if you have tried it or not but sometimes warming up their food can help. It will make it more smelly and attractive to them. Also if you haven't already you might want to try a can of fancy feast. Most cats find fancy feast to be irresistable, I would go with one of the classic pate non fish flavors. Also not sure if it has been mentioned here or not, but you could also try some gerber meats baby food. You want the stuff that is just the meat with nothing else added. It is not something that you want to feed on a consistent basis, since it is missing essential things like taurine that cats need. But for a kitty that is not eating and isn't feeling well the important thing is to get them to eat what ever they may be willing to eat.
Hopefully your boy will start feeling better, he is a very handsome looking guy. As for the vet if she is still insisting on the surgery, you may want to consider getting a second opinion. I know that you guys are trying to get things in order for the new place you will be renting, and that can make money tight. A second opinion will be cheaper than surgery and if the second vet recommends surgery also, it is at least peace of mind before making such an important decision for your boy.
Finally if Sammy still doesn't want to eat you may need to see if he needs an appetite stimulant, or you may need to assist feed him. I am sure with the pain that he is in he doesn't want to do much and the antibiotic could be making him feel nauseous which can make him not want to eat. Also one last thought that came to mind with feeding. My boy when he wasn't feeling good after being diagnoised with ckd would not eat much on his own. I did find that if I added some water with the canned food, warmed it up and held it under his head he would eat a little bit for me. It wasn't much at one time, but I would continuously offer him food and it would add up.
It is good that Sammy is drinking. Since he seems to like running water, you might want to consider buying a water fountain for him to help to encourage him to drink water as he is getting over everything that has been going on now, and also to help to promote him and your other cats to drink when everyone is healthy.
For eating, not sure if you have tried it or not but sometimes warming up their food can help. It will make it more smelly and attractive to them. Also if you haven't already you might want to try a can of fancy feast. Most cats find fancy feast to be irresistable, I would go with one of the classic pate non fish flavors. Also not sure if it has been mentioned here or not, but you could also try some gerber meats baby food. You want the stuff that is just the meat with nothing else added. It is not something that you want to feed on a consistent basis, since it is missing essential things like taurine that cats need. But for a kitty that is not eating and isn't feeling well the important thing is to get them to eat what ever they may be willing to eat.
Hopefully your boy will start feeling better, he is a very handsome looking guy. As for the vet if she is still insisting on the surgery, you may want to consider getting a second opinion. I know that you guys are trying to get things in order for the new place you will be renting, and that can make money tight. A second opinion will be cheaper than surgery and if the second vet recommends surgery also, it is at least peace of mind before making such an important decision for your boy.
Finally if Sammy still doesn't want to eat you may need to see if he needs an appetite stimulant, or you may need to assist feed him. I am sure with the pain that he is in he doesn't want to do much and the antibiotic could be making him feel nauseous which can make him not want to eat. Also one last thought that came to mind with feeding. My boy when he wasn't feeling good after being diagnoised with ckd would not eat much on his own. I did find that if I added some water with the canned food, warmed it up and held it under his head he would eat a little bit for me. It wasn't much at one time, but I would continuously offer him food and it would add up.