Should I get a companion for my sick dog?

[veruca108]

Last year my dog was diagnosed with a liver shunt so he's been on special food & meds for a year and will have to be for the rest of his life. He's doing well though... perky and happy. We had to put our cat down last week (his best friend) and he's been pretty depressed about it. He's home alone now during the day and seems depressed at night. I'm considering getting another dog so he can have a companion. I always wanted two dogs but I worry my sick dog might be jealous or not adjust to it. On the other hand, I see how depressed he is since our cat died. Any thoughts?
He is actually only 6yrs old. I thought about a cat but my husband isn't very fond of cats and to be honest, I'm more of a dog person myself. Thanks everyone, I really appreciate your help : )