Thank you so much for giving another possible diagnosis, especially with the elderly it is important to correctly identify what is wrong and treat it as quickly as possible. I had a tech tell me once that the Prednisone I was giving an elderly cat would cause problems if used long term, I replied that he was dieing from cancer and had no long term, and if this made him more comfortable I would give it as long as he needed. There is another forum up at the top for 'cat health' (click on 'forums'), feel free to post there too, it really might help someone .Always ask the advice of your vet before using anything like Ivermectin, only TINY amounts are used and need to be correctly measured. My vet has treated my ferals with it for ear mites because it usually takes care of this problem with one dose, and it is a inexpensive med too.Insulin syringes were used because of the tiny amounts. Once again, thank you, and welcome to the Cat Site!