One of my cats had a problem with her legs, she could not stand up. This happened approximately one week after her vaccination. For 10 days she was so sick that I was afraid we would lose her. I had to leave the country during that period and my mother was doing everything to help her, including calling a naturopathic doctor. The doc prescribed my cat a cleansing/detoxification drops. It helped. I will never again vaccinate my pets for anything other than rabies - and only ONCE.
Now, my other cat has a problem with his hind legs. He was given Revolution. I wonder if it had anything to do with his condition.