My dog does that when he gets into really cold water - just for the first minute or so, then he's fine. Never really investigated too much as it never mattered, but your cat sounds like it's a bit more serious and I would definitely ask the vet about it because you don't want it to develop into anything more serious. Guessing at the reason (some neurological glitch, arthritis, whatever) is not going to help, and vets will have a much longer list of possibilities than we can think of.
Originally Posted by kunalen
My cat at times witout any warning develops a cramp in one of his legs.He limps for a while and then he is fine.Hope someone can indicate any causes.