If you have ever, even for a moment, been afraid of your dog or what he might do, you need help, whether you realize it or not.

Aggression in dogs has both genetic and learned factors. Some dogs are born with the potential to be aggressive, and that potential can be fully realized in a home that either encourages aggressive behavior or is ill-equipped to cope with it. Other perfectly nice dogs can become unreliable fear-biters because of abusive treatment -- and remain time bombs in new homes.

Maybe you prefer to live in a state of denial, hoping nothing awful involving your dog will ever happen. Nearly 4.5 million American dog owners are jolted into reality every year -- 4.5 million being the number of bites reported in the latest Journal of the American Medical Association, based on surveys by researchers at the Center for Injury Research and Control at the University of Pittsburgh. The researchers also reported that in 1996, 334,000 dog-bite victims ended up in emergency rooms, and 20 died.

Is your dog potentially dangerous? Answer these questions, and be brutally honest:

-- Has your dog ever "stared you down"? I'm not talking about a loving gaze -- my dogs will hold those for minutes at a time. I'm talking about a hard, fixed, glassy-eyed stare that may be accompanied by erect body posture -- stiff legs, ears forward, hackles raised.

-- Do you avoid doing certain things with your dog because they elicit growling or a show of teeth? Are you unable, for example, to approach your dog while he's eating or ask him to get off the couch?

-- Do you make excuses for his aggressive behavior, or figure he'll "grow out of it"?

-- Do you consider your dog "safe" -- except around a particular group of people, such as children? When he growls at the veterinarian, do you tell yourself the behavior is reasonable, and a veterinarian should be able to cope with it, after all?

-- Has your dog ever bitten anyone, even if it was "only" once and because "it was an accident," "he was scared," "he's usually so good!" or some other equally inexcusable rationalization? Little dogs often get excuses made for their behavior, but growling and snapping is no more acceptable from a Pomeranian than from a pit bull.

If you have a problem, get help. Now. You should no more attempt to cure aggression yourself than you should try to treat cancer. The reason is the same: You haven't the training and the expertise to do so. If you suddenly try to eliminate your dog's self-appointed role as leader of your pack, there'll be trouble.

Ask your veterinarian for a referral to a trainer or behaviorist with experience in aggressive dogs. And realize from the start that just like cancer, aggression is a disease that is sometimes not curable. Have your dog neutered -- most dogs involved in attacks are young, unneutered males -- and follow the expert's advice on retraining.

If in the end you have a dog who still cannot be trusted, have him euthanized; it's the only responsible thing to do. Yes, it's hard. But if your dog is a biter, he'll probably end up euthanized eventually. The difference is that if you wait, someone will get hurt first.

Finding an aggressive dog a new home -- one with no children, perhaps -- is not the answer. Children are everywhere, and you may be responsible for one of them being hurt if you pass a problem dog onto someone else. Especially if you do so without admitting the real reason you're finding him a new home, knowing that no one will adopt a biter. You do the dog no kindness, and you put the new family at risk.

Canine aggressiveness never improves on its own. Get help, before someone gets hurt.

Pets on the Web: The American Miniature Horse Association's Web site is a good first stop for anyone who has ever thought about owning the only kind of horse that's truly "pet-sized."

The site (http://www.minihorses.com/amha) gives the history and current status of these petite ponies (they cannot be more than 34 inches at the withers) as well as information on purchasing, care and showing.

Gina Spadafori is the award-winning author of "Dogs for Dummies" and "Cats for Dummies," and is the editorial director of the Veterinary Information Network Inc., an international online service for veterinary professionals. Write to her in care of this newspaper, or e-mail to Giori(at)aol.com.

4520 Main St., Kansas City, Mo. 64111; (816) 932-6600

My friend Rita used to keep a page from an old calendar in her desk, the date marking the occasion I foolishly said, "I'll never have more than two dogs."

She thought the statement amusing, since I've rarely had fewer than two dogs for any great length of time.

With the rather unexpected arrival of a third dog the day after Christmas, I'm thinking of making a new rule: Never have more dogs than you can fit on the bed.

Since the new dog, Heather, is my second full-grown retriever, I may have to get a bigger bed soon. In the short run, though, the challenge is dirt and fur. With two big dogs (the retrievers Benjamin and Heather) and a medium-sized long-haired dog (the Sheltie, Andy), I have plenty of both.

Domesticity has never been my strong suit, but I cope as best I can. I cling to my dog-eared copy of Don Aslett's sadly out-of-print "Pet Clean-up Made Easy" for advice. (Aslett's other cleaning books are also valuable to pet lovers, although the advice is more general.)

Here are a few of his suggestions -- all of which have earned Gina's Bad Housekeeping Seal of Approval -- for those who like not only a moderately clean house, but also pets:

-- When choosing new carpets, forget wool and cotton and go for all-synthetic fibers. Natural fibers absorb everything, and that, says Aslett, guarantees stains and odors. Better still are all-synthetic carpets with stain repellents built in. Aslett suggest a textured or multilevel loop, not a deep shag, which is hardest to clean and provides the snuggest home for fleas. Varied hues of the same color hide dirt and stains the best, he says, and even better is matching the carpet color to your pet.

-- Opt for tightly woven, smooth-surfaced upholstery. Such fabrics will resist a few claw marks and will not encourage a furniture-scratching cat. Steer clear of highly textured, nubby fabrics and wicker. "Anything with a loose or open weave invites cats and dogs to pull at it, fiddle with it, claw or scratch it," he writes. (Providing your cat with a cat tree and teaching him to use it is the second half of the no-scratch equation.)

-- Make use of mats everywhere. Rubber-backed mats of synthetic pile collect dirt and moisture and clean up easily. Aslett suggests using them just outside and inside the doors, under food dishes and in sleeping areas. (They make great beds for older pets who "leak.") A great suggestion from a reader: Car mats work just as well.

It's a good idea to keep a towel handy and teach your dog to wait on whatever mats you use until you wipe off his dirty paws. Sounds like too much effort? Consider this: Would you rather spend a few minutes teaching your dog to wait for a wipe-off, or the rest of your life cleaning up muddy foot prints?

-- Clean up spills and messes immediately. "You can't let a pet mess go until it's convenient," writes Aslett, "because if you leave it, the mess will spread, stain, smell, attract pests and encourage repeat offenses." Look for cleaners with enzymes at your pet-supply store; I've found they do the best job. A serious no-no: Never use an ammonia product to clean up, especially if the mess is urine. Ammonia smells like urine to your pet and will invite a new mess on the same spot.

My own tip to add is grooming, which is good for your pet, good for your relationship with your pet, and good for the general cleanliness of your home. Not only will your pet be more attractive and happier for the extra attention, but every piece of fur you snare you'll spare from a future home on your floor or sofa.

Pets on the Web: Rabbit-lover Beth Mammini has pulled together a delightful collection of links on her Bunny Home Pages site (http://www.alumni.caltech.edu/(tilde)meanie/petbunny.html). The Web site features the pages of more than 100 individual rabbits in the United States and around the world. Of more practical use is the information on Etherbun, the electronic mailing list devoted to the care, behavior, health and biology of companion rabbits.

Gina Spadafori is the award-winning author of "Dogs for Dummies" and "Cats for Dummies," and is the editorial director of the Veterinary Information Network Inc., an international online service for veterinary professionals. Write to her in care of this newspaper, or e-mail to Giori(at)aol.com.

4520 Main St., Kansas City, Mo. 64111; (816) 932-6600

The decorations are coming down, the kids are back in school and the holiday bills are hitting the mailbox. And suddenly that adorable little puppy seems like a lot more work than you figured he would be when you put that bright ribbon around his neck a couple of weeks ago.

You're not the only one who's feeling that way.

In the months to come, the shelters will see a steady flow of young dogs, as the formerly adorables grow into their leggy adolescence, untrained, unsocialized and seemingly unredeemable. Too many will never get another chance at a happy home. The difference between the cherished and the throwaways? In your puppy's case, it's mostly you.

Yes, your puppy needs a trip to the veterinarian for vaccinations, parasite control and neutering. Yes, your puppy needs a warm place to sleep, good food, fresh water, and a collar with ID and a license. But year in and year out, the thing that dooms more promising young pups is not getting sick, not getting lost -- it's not being raised properly.

If you have a new puppy now, there's no time to waste.

Forget everything you ever heard about training starting at six months. If you let this go until summer, you may never recover the ground you lose now. Your puppy starts learning the moment he's born, and by the time you bring him into your life he's as absorbent as a sponge, trying to figure out the sights, sounds and smells of his new world and find his place in it. You need to help him find the answers, because you might not like the one he comes up with on his own.

It's not that complicated, really. Your puppy wants to be a part of your family, and he craves gentle, loving leadership. To raise him into the dog of your dreams, you must take time for the following:

-- Bond with your puppy. Bring him into your home, into your family, into your life. A puppy can't learn how to behave around people if he's never allowed in from the back yard.

-- Socialize your puppy. You cannot expose a puppy to too many things -- people, places and other animals. An unsocialized puppy too often becomes a shy or aggressive dog. Talk to your veterinarian about when and where it's safe to take you pup out, and then get him visiting. Puppy classes are especially good for this purpose; ask your veterinarian for a referral.

-- Never let your puppy do anything you wouldn't want a grown dog to do. Puppies are cute chewing on a slipper or jumping up for a slurpy kiss. Dogs are not. Remember always that preventing bad habits is easier than fixing them.

-- Teach your puppy using positive methods: Make training fun! No matter how bratty he is, no matter how tired you are, always reward your puppy for doing it right. If you find you're not getting through in training him, find a trainer and get help before it's too late.

-- Pay attention to both formal and informal training. "Sit," "stay" and "come" are all important, but your puppy must also learn things like tolerating grooming and nail trims, sitting for his leash and dish, and letting his veterinarian examine him. Make good manners a part of his regimen from the beginning.

-- Realize your puppy makes mistakes, and don't get angry when he does. He's a baby, and he's counting on you to help him learn. Anger never accomplishes anything. Take a break, call it a day, whatever -- but don't ever let your anger get the best of you.

Puppyhood is a special time, and it's over all too fast. Every minute you spend with your puppy is worthwhile -- not only now, when he's so cute, but later, when he's the wonderful dog you always dreamed of having. Investing time now pays off in a lifetime of love, and that's the best holiday gift of all.

Pets on the Web: The library of the University of Illinois at Urbana-Champaign has pulled together a good resource for anyone considering traveling by air with a pet. Their Pet Care Home Page (http://www.library.uiuc.edu/vex/cpl/faq/travel.htm) lists books and magazine articles on the subject, as well as links to pet-travel regulations for American, United, Northwest, Delta and TWA. A link to a Web site with an overview of the U.S. Department of Transportation's regulations for transporting animals by air can also be found on this well-organized site.

Gina Spadafori is the award-winning author of "Dogs for Dummies" and "Cats for Dummies," and is the editorial director of the Veterinary Information Network Inc., an international online service for veterinary professionals. Write to her in care of this newspaper, or e-mail to Giori(at)aol.com.

4520 Main St., Kansas City, Mo. 64111; (816) 932-6600