grooming problems

Question
our 1 yr old male springer spaniel has a lovely temperament except when i try to brush and comb him,he has very long hair and gets tangly easily. I know that sometimes this must hurt him but he gets so aggressive and tries to bite. i have tried a muzzle just for this purpose but it just makes matters worse. I have tried treats - but do I give these before, after or during? I have to find a way round this as leaving his coat to get matted is not an option. Any advice please?

Answer
I assume you didn't attempt to condition the dog to being groomed as a puppy.  Perhaps an initial grooming episode frightened or hurt him and you're seeing a reaction to that; on the other hand, some dogs demonstrate a tendency to rank opportunism by not tolerating being groomed.  I have no idea if this dog is behaving in a rank opportunistic manner in other areas of his life so I will address this as strictly a reaction to anticipation of pain during grooming.

You must recondition your dog to the grooming experience.  You need to introduce grooming tools in unexpected places at unexpected times and observe your dog's reaction to their presence.  If the dog is fearful or shows any aggression, do NOT offer any reward, simply ignore his response, leave the tools in a conspicuous place for a short period of time, then put them away.  Repeat this often and randomly for a couple of weeks until the dog's instant fear reaction is extinguished because the tools are never used.  If (and when) the dog tolerates the presence of grooming tools, offer small food reward when you introduce them and then periodically while you handle the tools (without using them on the dog), then put them away.  Repeat this for several brief episodes a day for a couple of weeks until your dog actively looks for the food reward when he sees the grooming tools.  During this time, condition your dog (separately from the presence of the tools) to a phrase (calming phrase) which he will associate with a special, small food treat.  You can use any phrase, one not heard otherwise.  Say the words, offer treat to the dog; repeat randomly throughout the day for the weeks you are reconditioning him to the presence of the grooming tools.  By the time you are ready to approach the dog with the tools, he should have acquired a conditioned response to your calming phrase.  Approach the dog with tools in hand, observe his body signals.  If he reverts to aggression or avoidance, go back to reconditioning him to the presence of the tools.  if he does not and shows no anticipatory anxiety toward the tools in your hand as you approach him with them, give him the calming signal, reward him, put the tools away.  Do this in very small steps until the dog will allow you to briefly (very briefly) use a grooming tool on his coat (no matter how long this takes.)  What you are doing is slowly desensitizing him to the grooming experience and building a new conditioned response to their use with positive reinforcement.  The actual use of the tools, the grooming itself, needs to be increased slowly with very close observation of the dog's thought process.  The moment you see a negative reaction, give him the calming signal, food reward his response to THAT (you don't want to reward his fear), and stop the grooming process until the next episode.  Do NOT force the dog at any time, for any reason, to "suffer" any grooming experience.  If you find it very difficult or impossible to recondition your dog despite the passage of some weeks, you will need a credentialed behaviorist to determine if the dog's unwillingness to be groomed is part of a larger problem such as rank opportunism.