Prednisone

My cat was recently prescribed prednisone to heal an incision on his ear where a mast cell tumor was removed that was malignant.  My vet wants to keep him on this indefinitely in case he has
a mast cell tumor internally.  Do I need to be concerned with him being on prednisone for a long
time?  I know a friend that had a dog that developed diabetes because of prednisone and am worried about this.
Rascal's mom

[Aleda M Cheng, D.V.M., C.V.A]

In your cat's case the need for prednisone overshadows your concern of developing diabetes or other disease's such as cushing's syndrome.  Low dose prednisone can be used indefinitely as long as it is the lowest effective dose and you supplement your cat's diet with hepatic protectors such as Milk Thistle, SAM-E and others.  You must also make sure your cat does not gain any excess weight.  Your cat's bloodwork should be monitored very often, and any abnormalities addressed immediately.