There is so information out there as far as how much is too much exercise for our puppies so please answer the following. We have 4 month old German Shepherds and we took them for a 4 mile walk in the early morning and now one of them is exhibiting some rear leg pain. Took her to the vet and she tore a pad in the front but back leg still bothering her. Vet did not xray but seems to think she is ok? Did we overexercise her? Should we get xrays? Could this be growing pains? Thoughts and comments are welcome?