Mystery solved. Max has severe IBD (irritable bowel disease), however, it was presenting in an atypical fashion - no loose stool or vomiting.
Specialty vet (internal medicine) said that while his kidneys are definitely not 100% normal, they were not consistent with his inappetance. The inappetence could be caused by gut or brain. Gut - IBD or intestinal lymphoma; brain - tumor. Recommended endoscope to diagnose/rule out gut issues...which are treatable. Brain tumor not treatable - provide comfort care.
We agonized over general anesthesia for endoscopy at his age (13) , but went ahead with it. Endoscopy visually revealed red, roughened small intestine, friable tissue (fragile, tears easily) and pathology report from biopsy confirmed severe lymphatic IBD (there are several types of IBD) and no sign of intestinal cancer/lymphoma. Bloodwork also revealed severe cobalamine (B12) deficiency, which comes with IBD.
Treatment was b12 injections (I can do them) weekly for 6 weeks then monthly afterwards, and prednisolone daily. Literally overnight after the first dose of pred, Max's appetite returned. His behavior also has changed - back to normal - more energetic, alert, engaged. Had 10 day check up at specialty vet today - he will taper down pred, and she recommended putting him on a Rx diet - hydrolyzed protein food. Check in at one month by phone, and two months in person, and then we will discuss whether he needs longer term pred or not.
We are so relieved... we know that with 13 year old there will be other things down the road... but we are happy to have his spirit back... poor baby, his intestines were hurting and he couldn't tell us!
Thank you all again for your help! |