I want to send my prayers to Buzz (and you) tomorrow. I know how difficult having a seriously ill pet can be.
I noticed you were asking about a drug you called "Proxicam". Please check the spelling; I have experience with piroxicam. PLEASE research this drug well and know any and all side effects this medicine can cause. Be prepared. PLEASE.
The reason I stress this is that my beloved little Scottish Terrier was prescribed piroxicam to treat suspected Transitional Cell Carcinoma for bladder cancer--she had a precancerous growth removed and the bladder wall remained thickened. My little dog was in fragile health when she began this treatment. It is important to know that. She was being treated for bacterial hepatitis at the same time. Her liver could not process the medication and it sent her into kidney failure. Piroxicam is an NSAID and one side effect is stomach ulcers. I called her internal medicine vet when she began vomiting and not eating. The vet began treating her for stomach ulcers. By the time we realized she was in kidney failure, she had so much damage there was little that could be done to help her. She spent the majority of her last few weeks in ICU being hydrated, only to come home a few days and back to ICU. We lost our little girl. In order to make our decision to let her go, the specialty vet did a final ultrasound. The piroxicam did work--her bladder wall was normal. Unfortunately her kidneys were gone, her liver was failing and she was bleeding in the GI tract. Remember, my dog was in bad health when she began her treatment. She lost her spleen the year prior and had many severe infections (including the hepatitis). It is probable that her kidneys were already damaged, but not severe enough to be seen on bloodwork (it takes 70-75% failure to show up on the blood panel).
I don't want to scare you away from this medication. It is used successfully to treat some cancers. But please know the risks involved. Please, have your dog's blood drawn very frequently to test the kidney function. It took less than 3 weeks for this medication to poison my dog. She fought bravely for about 6 weeks afterward, but could not recover. Just please, be careful....
Tipper--in my heart