Help my mom's aggressive dog!!!

[shellnooo]

My mother has a 16.5 year old carin terrier - she adopted him after he "retired" from showing and has always been skittish but over the past year or so, has gotten increasingly aggressive. He now bites when groomed (he got banned from his long time groomer) and when cared for (cleaning eyes) or when just spoked.

He has never been totally house broken and now lives in a condo instead of house/yard and my mom is older and is having a hard time caring for him.

The vet said there is no medication to help his temperment and the groomer recommended putting him down. I'm going to take him, and hope someone can give me advice on how to care for him.

His vision is very bad and I think that adds to his stress. I have a fenced yard and dog door although I'm not sure he will be able to see or learn how to use it so I may have to keep him outside during the day and crated at night.

What can I do to help him? How can I keep him clean? Any advice will be appreciated!