I have five foster kittens from the same litter, and one of the kittens has an atypical gait and rear leg weakness. She walks like a much younger kitten and falls over when she runs. She is also much smaller than most of the other kittens in the litter (she and one other kitten are the same size), but she appears to be healthy otherwise. She eats, plays, and acts like a typical kitten. But, there is definitely something "not right." It doesn't appear to be a spinal injury because her tail doesn't show any signs and both legs are affected, but I could be wrong. I don't think it's CH, but again, I could be wrong. She was treated for round worms and ear mites, but this problem has been evident since at least 4 weeks old.