Our corgi had his hip operated on with hip displasia when he was a puppy. Ever since then he has not recovered and is very sensative around his hip. Now, this has nothing to do with the thing above, i was just giving you history on our corgi. Well last weekend he attacked and bit another dog breaking the skin. He has never demonstrated this behavior before....and is there has been other occasions of him being agressive around small kids, cats(of course), and other dogs. What can i do to help him??

If his hip has never healed properly, is he in pain all the time? Even if it doesn't actually hurt and is just a bit sensitive, it would explain why he may be feeling threatened by other dogs and certainly small kids. He might think he has to "get one in first" before they hurt him!
Maybe a return trip to the vet would be in order, see if his discomfort can be alleviated somewhat?

I agree, if the vet will prescribe some strong painkillers for a bit, and the dog behaves much better and is more relaxed, then the answer is the hip problem.

Lindsay

Sounds like his hip is sore again, I agree, a trip to your vet as arthritis might have set in, it will set your mind at rest anyway. I know how I feel when the weather is damp etc. very sore, i've got arthritis.