lower backpain and hair loss

Question
Mork: nutered 9yr old mixed breed medium hair (strictly an indoor cat). has had some lower back discomfort over the past 8 mos. but it recently appears to be coming more painful as of late (to the touch not with movement). he does not let me brush this area and this morning i've noticed a patch of hair missing at the lower back base of tail area(not red or raw) can you help? He currently is on thyroid medication - Methimazole 5mg daily.  Thank you for your help and assistance.  

Answer
Hi John.  Has Mork seen the vet lately?  There are lots of possible causes for chronic back pain.  That includes arthritis, diabetic neuropathy (diabetes is very common in cats around Mork's age), Rolling Skin Syndrome, Lupus or other auto-immune disease, and Yellow Fat Disease (rare unless you feed him lots of fish-based food).  Those are just a few possibilities.  So I would get Mork in to see the vet ASAP and get him properly diagnosed and treated.