Hello. This is my first post here. 
I have two 13 y/o cats. They are brother & sister and I've had them most of their lives. My boy cat, Yaya, has always been my social and outgoing cat. He is the one who would meet us at the door, wake us for food, greet all new guests, etc. On Christmas Day, we noticed he was a lot less friendly than normal and much less agile & athletic. After a few days of watching him stumble around the house, I took him to the vet. He had two visits in as many days. The main diagnosis was arthritis of his back and hips. He also has some kidney issues but the vet said that his main discomfort seemed to be from the arthritis.
After bringing him back from the vet, his sister Olivia was unhappy to see him. I've experienced this before; normally it is her going to the vet and him hissing at her for smelling different for a few days. However, he lets it go after a day or so. Well, here it is almost ten days later and his sister is still hissing at him on occasion. They are normally very close cats (that's them in my profiel pic) so I don't know what to do about getting them to be friendly again. They are able to eat side-by-side, they just don't cuddle or socialize anymore.
Adding to this, I have to give Yaya meds now. They seem to be helping his agility, but now he won't come near me or my fiance apparently out of fear that we are going to grab and pill him. He spends all of his time now under the bed in the spare room. I'm worried that his isolation will turn into depression.
Does anyone have any suggestions about how to get my sweet, friendly (loud and obnoxious) cat back into the family circle? I miss him very much, even having him pester me for constant attention.
Thanks!











