Prednisone & Meloxicam

My 15 1/2 year old Golden Retriever/Lab has multiple mast cell tumors. I decided against surgery and just want to keep her comfortable. The vet prescribed 20mg prednisone to see if it will shrink the tumors some. They seem to be growing rapidly in her neck area. Since she has been on meloxicam for a couple of years, I was told to take her off that before giving her the prednisone. The vet suggested not waiting an entire week because being off the metacam that long will be hard on her hips and the tumors are growing. Is it safe to  only wait 3-4 days?? She suggested Omeprazole to prevent stomach ulcers.
Need a second opinion.

[lfinfl]

Hi. I'm sorry to hear about your pet. Meloxicam is an NSAID and prednisone is steroid and these two cannot be used together without significant risk of stomach ulceration (some dogs have even developed bleeding ulcers). Your vet could have dispensed something different (like tramadol) to use in the transition. GI protectants would be appropriate too. I hope this answer didn't come too late to help you. good luck.