Safe to Withhold Food for 12 Hour Fasting Lab?

My cat isn't on insulin, yet. Her glucose was around 550 last week and I switched her to a canned only diet. She's not eating (nothing to do with the food change) so I'm syringe feeding her. She also has high creatinine and BUN. She may have tumors/cancer as her abdomen is kind of big considering the rest of her is so thin. She may also have other organ failure. Her x-rays were ok. I'm looking into doing an ultrasound.

The vet wants to do a 12 hour fasting lab. I agree with checking lab work again, but I didn't think it was safe to withhold food from diabetic cats, or does that just apply to the ones on insulin?

 

How necessary is this lab work? How old is your cat?
It's been my experience most tumors show up on x-ray first and are then confirmed by further investigation. A needle biopsy is one option and requires only local anesthetic, it's done while you wait. I can't speak as to the insulin, I'm more worried about your cat already being syringe fed and the stress of this knocking her down. There's nothing wrong with a bit of suffering now for the greater good. Cancers have to be diagnosed by looking at the cell structure under a slide, a mass could be anything and in our case it was a cyst in the GI tract.

 

If she is not on insulin yet, then fasting shouldn't be an issue. If she was on insulin...you would do a reduced dose or skip.