Reptile & Amphibian Forums

If all is clear on the health front, then the problem is behavioral as your vet first suggested. You will need to take steps to retrain the cat to the box. Basically this involves confining him to a small room with just the litterbox, food and bedding. As the cat begins to use the litterbox consistantly, you widen the area he can roam in.

You need to thoroughly deodorize wherever the cat has been peeing. It is the smell of the "accidents" that causes a cat to reuse the place and an enzyme cleaner will do away with the smell. Nature's Miracle is highly recommended and is available at most large pet supply stores.

Check into using Feliway, a spray that mimics the happy scent cats leave when they rub their check against something. You can get it from your vet or from Cat Faeries at http://www.catfaeries.com
If you visit the website, you will see a phone number that you can call and for a fee discuss your cat's problems with someone. The person who does this is very knowlegeable and it may be worth the $$ for you. There is also a Feliway plug-in available at http://www.drsfostsmith.com and there is a Feliway website at http://www.feliway.com.

Finally, if all else fails, ask you vet about changing the medication to an antianxiety medication such as Buspar or Prozac. These very often work, however the decision to prescribe them will rest solely with your veterinarian who will be able to monitor the dosage and side effects.