Why are only 2 of my cats losing hair on their hind quarters?

I have a total of 6 cats and 2 of them are losing their fur on their hind quarters. On both of them the hair loss starts at their hind legs and ends about mid tail. Both of these 2 are runts of their litters, could that be why only they have this problem? And they both are contantly cleaning and licking the areas where the hair loss is occuring. Could there be something seriously wrong?? I've taken one of the cats to the vet and they say there isn't anything physically wrong with them other then the hair loss and the only thing they can think of is that she has allergies, but I don't see that being a reason for her to lose her hair. That and I've elliminated everything she could possibly be allergic to. We have no plants or anything along those lines in the house. We've switched to all natural cleaning supplies and nothing has helped my kitties with their problem. PLEASE HELP FOR THE SAKE OF MY BALDING KITTIES!

Why are only 2 of my cats losing hair on their hind quarters?

I would get another opinion from another vet, because that is quite unusual for that to be happening. They could possibly be allergic to something. But you should get a second opinion. Good luck, and I hope your cats feel better!

Why are only 2 of my cats losing hair on their hind quarters?

have they got flees,if not done latlely get done

Why are only 2 of my cats losing hair on their hind quarters?

I WOULD TAKE THEM TO THE VET YOU MIGHT HAVE RING WORM IN YOUR CATS SOME DO NOT SHOW SIGNS BUT KITTENS DO REALLY FAST AND BADLY AND IT STARTS ON THE FEET THEN ON THE FACE WHERE THEY SCRACH GET THEM TO CHECK AND FAST.