Cat with elevated eosinophil levels

My cat has loose stool and a history of intermittent colitis. In the past the colitis presented with some blood in the stool and mucous. She got a steroid for it in pet tinic.  This time, her stool is completely loose with some mucous.

She's 8 so the vet did an x ray to exclude obstruction and ran a CBC. She had a CBC in May for dental work and her eosinophil levels were 4% but yesterday they were 35%. The vet said it could be allerg, irritable bowl disease,  whip worm (which would be weird because she's indoor) or a mast cell tumor.

The x ray showed "gas in the colon" but I wasn't clear if it was a normal amount of an empty colon, or excess gas. Her liver extended a bit past her rib cage which the vet didn't like.

She wants to do a fine needle aspirate of the liver and spleen (liver levels were slightly elevated but I don't know what the reading was). Her white cell count was slightly elevated and she has low thyroid.

She's enormously fat and has been on a canned food diet to eliminate too much carb. In May she was 19.75 pounds and yesterday she was 18.5 pounds. While we struggle to help her lose weight, we've not ever been that successful, so I worry the weight loss is due to something like cancer.

The vet suggested a full biopsy and ultrasound. Also offered exploratory surgery. We don't want to put the cat through surgery or the pain of a biopsy, especially if it is IBD.  

She got a shot of antibiotic at the vet and a 5 day course of Metronidazole and a dewormer. I want to see if this works and the vet said to wait might give a false sense of security while mast cells move through her system. My feeling is that if there's been this much change since May, and it is cancer, it's pretty agressive. I sure don't want to put her through the treatment since it would be so unpleasant for her and she wouldn't understand why.

However, if it is IBD, I definitely would be more than happy to adjust her diet and give her the appropriate medication, although the cat would especially appreciate it not being metronidazole! It's very difficult to give her the pill and the medication is apparently quite bitter.

The vet said that her "colon is clearly unhappy" from the appearance on the x-ray. It seemed to have ripples in the edge.

The big kitty also has a slight fever.

I don't know what to do!

[Savas]

For starters I'd put her on a Low fat/protein food. I beleive Regal makes a good one. They have one called "sensi-bites", but I'm not sure if it's low fat/protein.

The advantage is it's a human grade food as opposed to pet grade. The pet grade foods have A LOT of filler in them (corn, grains, etc) that cats can't really digest well. They tend to cause problems with digestion that lead to intestinal scarring that later leads to tumours (worst case scenario here).

Without getting too into issues of digestion and energy including thermogenesis and metabolic rates; a cat will eat until it is satiated. A cat is satiated when all its vitamin requirements are met when eating.

So use a high quality human grade food. Your cat will be able to fulfill those energy requirements because the food is more digestible, has a higher nutritional value, and thus stop being a little piggy because she doesn't feel "full". :)