Biting behavior from a normally good cat
Sorry, but I have to set the scene for this...
My mother-in-law is 90 years old, tiny, still lives in her own home, and until recently has had two cats, both adopted as strays 7 or 8 years ago.
Blackie was a big old chubby black shorthair, calm, laid back, not terribly social, but definitely not anti-social. Muppy is at least part Maine Coon, large, long haired, great temperament, friendly, outgoing, and loving.
Since she lives down the street from us, I go over and trim the cats' nails when necessary, and help her when it's time to take them to the vet and stuff like that. As an aside, MIL is just starting to slip mentally, but she's still mostly with-it.
In October, it became evident that Blackie was not well. MIL has a vet that makes house-calls, so Dr. G. stopped by to see what was wrong. She diagnosed liver failure, as the cat wasn't eating or drinking and had lost quite a bit of weight. To make a long story short, after about a month of waffling, MIL finally decides it's time to put Blackie out of pain, so in early December, Blackie goes to the Rainbow Bridge, and MIL is down to one cat. (trying not to sound callous, it was a bad time, and we all were sad, but it had to be done, the cat was dying before her eyes, and was clearly in pain.)
So anyway, now it's a one-cat household, with Muppy as king of the hill. Except that Muppy has now become rather anti-social, preferring to hide in the basement than come up and socialize. And when he does, he''ll only tolerate so much--then he bites! He's NEVER done anything like that before!
I was trimming his nails the other day, and he bit me twice! Not hard, but hard enough to just break the skin. If I had been just petting him, I would have said "Ouch!", blew in his face, and walked away, but I needed to finish with the pawdicure, so I just did the "ouch" thing, and kept trimming.
MIL has admitted that he's bitten her a few times recently, too, while she's been petting him. The behavior seems to have started after we lost Blackie.
Do you think it's possible that Muppy is afraid that he's next? Is he missing his buddy? What would cause a normally very good cat to start biting like this?
I've coached MIL on what to do if it continues, how to discourage the biting, but what if he doesn't stop doing it? She's 90 and her skin is like tissue, Muppy could do some real damage if we're all not real careful.
I'd be grateful for any suggestions!