Have Cat Questions? Ask a Cat Vet Online.
I suggest keeping a close eye on him to be sure he is passing urine. If the cat stops this can be deadly. The cats urethra is very narrow and if it blocks up the blader can rupture and cause an infection to rapidly spread thoughout the body. I suggest if he is unable to urinate to get him back to the Vet asap. I am going togive you a link to read about this as it can help you understand what is happening and what can be done to help the Kitty. Joan
They should have done a check on the urine for crystals and checked your boy for stones. They should have also put him on a special diet in a case like this. If he is not drinking you can entice him with some Tuna water or some plain broth 50/50 without garlic or onion. This will help get some fluids into him.You can even use some water in the canned cat food to help get some fluids into him. I would get him back into the Vet in the AM to have him further evaluated. If he blocks completely tonight then I would see the ER Vet tonight. There is something going on with him and it needs to be found, so he will not have the pain and discomfort he is facing and the worry for you. Joan