Q: We have a nine month old Golden Retriever. He has been to obedience school but still has a few problems. I know it is rare for a Golden Retriever but he sometimes becomes very aggressive. He will bite us but it is always in a playful manner. It is not really a hard bite but he will not stop when we say "no." We have tried to squirt him in the mouth with lemon juice when he does it and that tends to work, but what do we do when we don't have the lemon juice handy? Any advice on this or anything else about Golden Retrievers would be appreciated. Thanks!

A: First off, it would be irresponsible of me not to recommend you meet with a trainer or behavior specialist in person with the dog, to get an expert evaluation of what this interaction means. You need to make sure you don't have a dog that is a danger to your family and others. At his age, things could get worse if he has serious temperament problems.

Secondly, more obedience class. Goldens were bred for work, and a commitment of several months to weekly obedience classes and daily practice is often necessary to harness all this energy and drive. It's not a breed that tends to mature rapidly, so your dog may be 3 to 4 years old before puppy exuberance tones down. The more obedience command skill you and the dog develop, the easier life will be for you both. Do some work on retrieving, too, which is a natural way for a Golden to occupy his mouth and keep it out of mischief.

Third, I like to teach a dog the proper use of its mouth around humans in a very positive way. I start teaching the "Close Your Mouth" exercise when I first get the dog. This is gentle, but when you stay with it consistently, it makes a wonderful change in the dog, without risking adding any new problems.

Starting at a quiet time, I have the dog in a seated position and hold the collar at the back of the dog's neck with my left hand, just for leverage if needed. With the right hand, I gently but firmly encircle the dog's muzzle and hold it closed--painlessly, not causing the dog to bite its own lips or tongue. I hold the mouth this way for 15 seconds, while saying in a praising tone "[Dog's Name], Close Your Mouth! Good Close Your Mouth!" Remember, no longer than 15 seconds, and this is praise. You are teaching the dog a new command, and having the mouth restrained can be frightening to a dog. You are at the same time teaching the dog not to fear you restraining the mouth, which will enhance your control of your dog in many situations.

You won't need to hold the collar once the dog gets used to this, and you will be able to start introducing this exercise every time the dog puts his teeth on anyone. Don't wait until it annoys you or it hurts--it has to be every time the dog puts teeth on human skin. Otherwise the message is not clear to him. Soon you will be able to just say "Close Your Mouth," to remind him not to touch people with his teeth. And soon after that, he just won't ever do it anymore. Remember to praise when he obeys this command, just like you praise for every command a dog obeys.

Lastly, I recommend that every day you comb or brush through every bit of this dog's coat. It will give lovely benefits to skin and coat, but perhaps even more importantly are the benefits on the dog's tolerance of handling, enjoyment of your touch, improved relationship with humans, and increased responsiveness to commands. I use a Belgium-made Greyhound comb to groom my dogs, one comb for a lifetime, about $15 in dog catalogs--or you may find a tool you like better. I would not use a slicker brush, because unless you are skilled with it, it can scratch the skin and make the whole process painful instead of what it needs to be.

Discipline yourself to do this daily, and to go through all the coat, not just the back/top of the dog, as most people do! Once you and the dog get practiced with grooming, you can probably do it in about 15 minutes, though you may linger longer to snuggle him! You will be amazed at the benefits, and this is something you'll be able to do while watching TV or talking on the phone, so it need not disrupt your life at all. I just keep a worn bed sheet handy, and drape it over myself, tie it up around my neck, then work on the dog on my lap or the floor, with the sheet to catch all the hair. Every few days the sheet goes through the washer. This prevents grooming from being a big mess, and the daily grooming also reduces the hair your dog leaves elsewhere.

Daily grooming may not seem to pertain to mouthing problems, but it really is amazing how much it gets you in tune with your dog and your dog in tune with you. No matter how good the relationship between owner and dog, this will make it even better. Goldens have sky-high potential in so many areas, but their owners have to work at it. Good thing it's fun!