Dear friend,
Harley may have hyperthyroid as you suspect, however, his symptoms could also indicate, diabetes,or liver or renal issues. Sometimes older cats experience a decrease in kidney function or sugar in their blood. Either issue will cause itching, shedding and hair loss. An increase in appetite can also be caused by any of those disorders. The good news is tha tmost of the ailments affecting the senior cat now have excellent treatmens and cats are living to twenty or more. Harley should a checkup and he bloodwork evaluated.He sounds like a wonderful boy so lets get him right back on the road to good health.
If you would like any links to specific disorders like, hyperthyroid, renal, liver, diabetes, etc, just let me know and I will be happy to help in any way possible.
Very sincerely,
Terri
Dedicated to Cats and the people who love them!
Please press ACCEPT if my answer was helpful and leave feedback Thank you! Terri