Yes, cats do seem to get viral infections more than dogs. Feline distemper was the only contagious disease we frequently saw at the vet. If I had an indoor/outdoor cat and there were strays in the area, I would give it the feline shots. If it was stickily indoors, I wouldn't bother.

25 years of owning dogs and I've seen three aliments. My mother showed dogs and came back with kennel cough. Annoying but not fatal. Had an outdoor dog that had a running nose and sinus infection. Fed it eggs and it cleared up. It also had a chronic ear infection that never went away. Put a couple drops of diluted tea tree oil in his ear every other week, and it kept it from coming back.