Biting and Growling

Question
We rescued a dog who bites and growls at us. We already got him neutered and that doesn't seem to be helping. He goes from sweet to agressive all the sudden for non reason. Any suggestions on how to stop this?

Answer
There are several reasons this behavior might be occurring.  One, the dog is very fearful and your behavior might be threatening (over dominant) or triggering a conditioned response acquired in his former life.  The other is that he may have acquired a fear response to being touched as a result of his neutering experience.  Or, he may be generally fearful and is not comfortable in his new surroundings and is responding in fear.  The other is that he may be experiencing a rank related problem, attempting to acquire dominance in his new environment (very unlikely, however.)  Whatever the cause, it's absolutely impossible to determine from such a short question with virtually no history and description of behavior.  You need to obtain a credentialed behavior expert. Call the nearest veterinary college and ask for a referral to a Ph.D. or DVM with experience in assessing active aggression.