Why does the cat who just came in now want to go back out -- and vice versa? Is he just trying to drive you crazy? Of course he is, but there's more to the story.

Cats like to keep an eye on their territory, and if their territory includes a piece of the outdoors, they're going to want to check on it frequently. And after they're out, who's looking after their indoor turf? The cat needs in to check. And check. And check.

And besides, can you honestly say you have better things to do than to serve your cat? Your cat doesn't think so.

If you disagree, then installing a cat door can end your days as door opener. Cat doors aren't just for indoor-outdoor cats, either: Putting one in as a gateway to a screened porch is a great way to give your cat safe access to the smells and sounds of the great (and dangerous) outdoors.

The basic cat door has a flexible plastic flap that opens as your cat pushes on it and seals shut again with gravity -- and sometimes magnets -- to keep the heat, cold and wind out after he's passed through. Although these flaps are fine for warmer climes, they may be a little drafty in areas with more severe winters. More expensive models are available that do a better job at keeping the weather out, so look around. Some folks have also gotten creative in installing the doors. I've known people who've built tunnels with pet doors at both ends to minimize drafts.

If you have problems with neighbor cats coming in, you can find cat doors that work electronically, opening only for those cats wearing a collar with a special battery-operated transmitter -- yours. Stray cats aren't the only animal who can learn to use your cat's door, of course: Raccoons and opossums can too, and so can skunks. The other problem with cat doors is the things your cat can bring through them -- all manner of prey, from small mice to large, angry birds.

The convenience is probably worth it, though. You have a couple of options in installing cat doors. While most people put them in a door, they can also be installed in a wall, and most manufacturers include directions for both. If you have a sliding-glass door, you can buy panels with a pet door built in that fits on the end of the slider.

After you install your cat door, just leave it be for a week or so until your cat takes its presence for granted. (Always remember that cats aren't keen on change.)

To teach your cat to use the door, tape the flap up securely for a few days so that he comes to appreciate the fact that he can conveniently come and go on his own schedule through this magic portal. (And I do mean securely. If your cat gets clobbered by the flap, it takes a long time to coax him near it again.)

Then put the flap down and put a little butter or margarine on the bottom edge of the flap and encourage him with tasty treats and praise from the other side. You can also drag toys on a string through, encouraging him to chase them.

Repeat in very short intervals over the course of several days and your cat will get the hang of it, sure enough. If you have another cat who already knows how to use the cat door, you usually don't need to do anything. Your new cat or kitten will learn from the other cat (or even from your dog, if the pet door is shared).

Once your cat learns, your days of servitude are past. Except for feeding your cat, grooming your cat, petting your cat ...

PETS ON THE WEB

The Westminster Kennel Club dog show is just a dog show the way the Kentucky Derby is just a horse race. Westminster is the only event of its kind with widespread name recognition. Wining there is about as good as it gets for the owners and handlers of the nation's top show dogs -- even despite the most dreadful setup imaginable. If there's a worse place for a dog show than midtown Manhattan in February, it's hard to imagine. The show is Feb. 14 and 15 in Madison Square Garden, but you can get an early preview on the WKC's Web site (www.westminsterkennelclub.org).

THE SCOOP

Don't play tug-of-war with your dog, especially not if you have one of the more protective breeds or mixes. What seems like an innocent game could be a setup for tragedy, because this is one game that can teach your dog to be dominant. Here's how: You play with your dog, pulling against him in a battle of dominance, however playful in appearance. You get bored or the phone rings, and you drop your end. You think: Game's over. Your dog thinks: I win. It's exactly the opposite message your dog should get, and it may lead to other dominance challenges. A better game is fetch, which gives your dog a good workout and reinforces your role as leader.

QUESTIONS FROM THE PACK

Q: The time is right to add a sheltie to our family. We are trying to be careful with our purchase. At first we went to a pet store that had what I fear are puppy-mill pets. We've also been searching the newspaper classified ads since November with no luck. I've also tried searching the Internet.

There is one breeder who seems responsible that I was told is a "backyard breeder." What's wrong with that? I was also given the names of some breeders expecting pups. No one had any available now.

It's difficult to know what to do and whom to believe. What's a person to do? -- E.D., via e-mail

A: A well-bred, well-socialized Shetland sheepdog is a wonderful dog. I've shared my life with a few, including the only sheltie I have now -- Andy, who is coming up on his 14th birthday, still healthy, smart and loving.

I've had shelties for more than 20 years, and I've volunteered fostering and placing unwanted shelties for a couple of those. The time I spent doing rescue work nearly turned me off the breed entirely. There are a ton of dreadful shelties out there, poorly bred to the point of being crazy, and sick besides. I'm not just picking on shelties, by the way. The same situation holds for any popular breed: goldens, Labs, poodles, Rottweilers and so on. Both casual breeders and puppy mills do their part when it comes to ruining a breed.

The problem with casual "backyard breeders" is that they are usually cheerfully ignorant of the damage they do. They aren't aware of congenital defects (such as hip and eye deformities), so they don't screen for these problems. They aren't aware of the value of careful socialization, so any socialization the pups get is accidental. The puppies are often weaned and placed too early, as well.

As for puppy mills, even if you put aside the significant potential for health and temperament problems with mass-produced puppies, you perpetuate a well-documented system of cruelty when you buy one of these dogs.

Finding a reputable breeder and buying directly from that person is the best way to get a purebred puppy. Reputable breeders plan their matches to improve the breed, screen for health problems and socialize their puppies.

Such breeders can indeed be hard to find. To get the contact for the national breed club, contact the American Kennel Club at either its Web site (www.akc.org), or by phone (919-233-9767). (At the Web site, click on "Buying a Puppy.") Someone there will be able to share with you the names of club members in your area. From there, it's a matter of networking to find a breeder who's planning a litter and to get on the waiting list for one of those puppies.

The decisions you make now will affect your family for years. Take your time!

The best explanation of how to find a good breeder is in the book "Your Purebred Puppy: A Buyer's Guide" by Michele Lowell. (Henry Holt, $14). I also wrote on this topic extensively in my book "Dogs For Dummies" (IDG Books Worldwide, $19.99). I strongly encourage you to find one (or both) of these in your local library so you'll be armed with the information you need.

Q: Charlotte, my scarlet macaw, is crazy for sunflower seeds. I feed her a pellet food sold by our veterinarian, plus lots of fruits and veggies. But she'd kill for sunflower seeds! I've read that they have an addictive substance. Is that true? It isn't hard to believe, knowing how nuts my bird is for them. -- G.K. via e-mail

A: The rumor that sunflower seeds are addictive has been floating around forever. I guess the answer depends on how you define "addictive." If you mean is there a substance in the seeds that alters the body's chemistry (like nicotine or morphine), then the answer is no. There's just no evidence that sunflower seeds can exert that kind of hold on a bird.

But if you mean addiction in the more casual sense -- like my "addiction" to chocolate -- then you're probably on to something. Many birds find sunflower seeds to be the yummiest of treats, but not all do. My Senegal parrot, Patrick, isn't at all interested in sunflower seeds -- but you'd better get out of his way when almonds or safflower seeds are available!

Seeds are fine as a treat, by the way, but should never be the sole diet for a parrot. You've got the right idea: a base diet of high-quality commercial food complemented by a wide array of fruits, vegetables, and healthy "people food" such as pasta, breads, cooked eggs and so on.

Gina Spadafori is the award-winning author of "Dogs for Dummies," "Cats for Dummies" and "Birds for Dummies." She is also affiliated with the Veterinary Information Network Inc., an international online service for veterinary professionals. Write to her in care of this newspaper, or send e-mail to writetogina(at)spadafori.com.

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

Why does housetraining fail? That's the question a lot of people ask themselves every day, usually while cleaning up after a growing puppy they ruefully admit is only "partially" housetrained, which is not really housetrained at all.

If you're struggling with a Christmas puppy who just doesn't seem to be catching on, take some time to review your battle plan, with an eye toward avoiding those traps that sabotage your efforts.

First among these traps is using a negative approach to housetraining. Successful housetraining requires setting up a potty schedule, limiting your pup's roaming options to areas you can supervise, showing your pup the area you want him to use, and praising him for going there. Generations may have followed the old "shove his nose in it and swat" method, but that doesn't work as well as a positive approach. You simply must go out with your puppy and praise him for getting it right. You're not being fair otherwise.

Even with a positive approach, people make mistakes. Here are a few things to remember:

-- Understand your puppy's physical limitations. Little puppies have little storage capability and need to be taken out frequently. Do not expect growing dogs to be able to "hold it" as long as a healthy adult dog can. If you must leave your puppy for the day, limit his wandering to a small area and put down newspapers to make cleanup easier. Don't punish him for any messes he makes while you're gone. Take him outside, let him relieve himself and praise. And clean up the mess inside without comment.

-- Remember how puppies work. Puppies need to relieve themselves after they wake up, after they eat or drink, and after playing. Make sure to take your puppy out then. Do not offer food and water on demand. Instead, offer them at regular intervals to help predict when your pup will need a trip outside.

-- Clean up mistakes thoroughly. What you can't see, a puppy can still smell -- and smells invite repeat business. Keep commercial products on hand that use enzyme action to break down the smell. White vinegar also does a great job of neutralizing the odor of urine. Don't use an ammonia-based product though: Ammonia smells like one of the components in urine to a pet.

-- Limit your puppy's wanderings. You wouldn't let a toddler explore your entire house without supervision; don't let your puppy, either. Close doors and use baby gates to keep your pup where your can keep an eye on him. That way, if you see him start to make a mistake, you can whisk him outside and praise him for finishing the job where you want him to.

-- Be patient and consistent. While some dogs seem to housetrain themselves, others are slower to learn. Just keep working at it.

If you're still struggling after a month or so (and especially if you're having housetraining problems with a grown dog), have your veterinarian check to make sure your dog has no health problems, and then ask for a referral to a behaviorist.

You can also get some excellent advice in two books -- one old, one new -- on the subject that go a long way toward explaining why your dog behaves the way he does. The late Job Michael Evans' work on the subject, "The Evans Guide for Housetraining Your Dog" (IDG Books Worldwide, $17.95), is a classic that's helped convert many recalcitrant Rovers. "Housetrain Your Dog Now" (Plume, $12.95), by Krista Cantrell, is a readable new book that stresses empathy and positive training.

PETS ON THE WEB

"Time spent cuddling hedgehogs is not deducted from one's life span!" So announces the Hedgehog Hollow Web site (http://hedgehoghollow.com/), a wonderful collection of whimsy and practical advice for fanciers of these prickly looking little animals. The host of this page is also the author of the Internet's Hedgehog FAQ (frequently asked questions), and you'll find links to the multi-part document on the site. You'll also find links to mailing lists and other hedgehog sites, along with lots of cute pictures and stories. Hedgehogs are illegal in some states (including California), but if you live where you can have one and have been wanting to learn more, this Web site is a great place to start.

THE SCOOP

Hairballs are normal for cats, as is watching where you walk to avoid the disgusting "gifts" that always seem to be left on the most expensive rugs in the house. If the problem is severe, your veterinarian may suggest the use of a mild laxative to help the hairballs pass through your cat's system.

You should also try combing your cat more frequently to remove excess hair. And you might try increasing the fiber in your cat's diet -- adding a little canned pumpkin daily is a great way that many cats enjoy.

Don't let your cat become a laxative junkie, as daily use decreases the absorption of fat-soluble vitamins. Hairball remedies should not be used more than twice weekly except on the advice of your veterinarian.

QUESTIONS FROM THE PACK

Q: My sister is allergic to cats and dogs. But as she has gotten older, that seems to have gone away. (She visits friends who have two very big dogs, but though they shed hair all over the floor and couch, she doesn't have any allergic reaction.)

Are there any kinds of cats with fur that won't make her sneeze? I really want a cat, but not if it's going to make my sister sick. -- S.F., via e-mail

A: A great many people who can tolerate exposure to dogs can't manage any time at all with cats before showing allergic reactions. Allergies to cats are so prevalent and so severe that they've been suggested as one of the factors in the increase in asthma, especially since more cats than ever before spend their lives inside.

Your sister may well be able to tolerate dogs for a certain period of time, but that doesn't mean she'll be able to live with one. And it certainly doesn't mean she'll be able to tolerate a cat. Any cat, by the way, because there's no such thing as a cat who isn't a potential allergy trigger. That's because it's not fur that causes the problem, but an ingredient in cat saliva that gets deposited on fur when the animal grooms and that spreads as flakes of skin and secretions commonly called "dander."

Some people survive well enough with animals and allergies, but it does require some effort. Some things that help include:

-- Keeping animals clean. A weekly water bath (no soap needed) for cats has been shown to reduce levels of dander and may make living with a cat workable. It's best if a non-allergic member of the family handles the pet-grooming chores.

-- Keeping animals out of sleeping areas at all times. While it's hard to give up the hot-water-bottle pleasures of sleeping with a pet on the bed, your body needs a break from the stress of fighting off allergens.

-- Limiting exposures to other allergens. Keeping all your allergies under control can help your body handle the exposure to a pet.

Most important is to work with an allergist who's willing to work with you. The one whose advice starts and ends with "your cat needs a new home" probably isn't the one to choose. Be aware, however, that that advice may well end up being the only thing that helps. Some people are just not meant to share their lives with furry animals.

Q: I'm tired of my cat knocking things off the shelves! I am a collector and have a lot of glass figurines, a few of which have been broken. What can I do to protect them from Calypso? - B.G., via e-mail

A: Practically speaking, you can't keep cats on the ground. The best you can do is display your treasures in ways that keep them safe or, at least, safer.

You might consider moving your collection to a single room and keeping the door closed when you're not around to supervise. Glass-fronted book cases are another option for keeping collectibles and cats apart.

Although it's probably best to keep your most valuable pieces where your cat can't get to them at all, other objects can be made safer from the wanderings of clumsy cats. Double-sided tape or Velcro can be used to "lock" objects in place on shelves, and can be found at any home-supply store. You can also try a product called Quake Hold, a putty that seals objects to their display surface. Quake Hold can be hard to find outside of earthquake-prone California, but your hardware store may be able to order some for you.

Gina Spadafori is the award-winning author of "Dogs for Dummies," "Cats for Dummies" and "Birds for Dummies." She is also affiliated with the Veterinary Information Network Inc., an international online service for veterinary professionals. Write to her in care of this newspaper, or send e-mail to writetogina(at)spadafori.com.

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

You can see in your puppy today what our ancestors saw when this astonishing trans-species relationship was just forming. In the eyes of that wolf cub thousands of years ago was the same thing that anyone who has ever taken home a puppy since can't help but notice: the beginning of a beautiful friendship.

There's no doubt, though, that many of these beautiful beginnings go badly wrong, and experts spend a great deal of time trying to find out why in hopes of stemming the flow of half-grown dogs into the nation's shelters. Wrong choices, bad timing and poor planning all play a part, but in many instances "too little" is the sorry epitaph that marks the end of a once-promising relationship. Too little time, too little training.

You don't want this to happen to you and your new puppy. Your concern is for your puppy and making sure he turns out the way you want him to. You don't want to be living with a canine terror a year from now, and you certainly don't want to be finding him another home because you can't handle him anymore.

You can make up a lot of ground with a puppy who wasn't raised under the best of circumstances before you got him, or you can totally undo the careful breeding and handling of your pup by a knowledgeable and reputable breeder. The decision is completely up to you. Ignore your puppy or raise him wrong, and you'll both be sorry.

Forget everything you ever heard about starting training at 6 months. Your puppy starts learning the moment he's born. By the time you get him, at 7 to 10 weeks of age, he's as absorbent as a bath towel, taking in the sights and sounds of his world and trying to figure out his place in it. The answer he arrives at on his own may be quite different from the one you want him to have, which is why you need to be involved in the process.

It's not that complicated, really. Your puppy wants to be part of your family, and he craves loving leadership. Just keep a few things in mind as you enjoy your youngster.

-- Bond with your puppy. Dogs are social animals. Don't throw your pup into the back yard, however nice the dog house you've put there. Make your pup a member of your family.

-- Socialize your puppy. Be careful with this until all the puppy shots are done -- no parks or areas where other dogs frequent. You don't want your puppy getting sick. But after the veterinarian gives the go-ahead, pull out all the stops. Expose your pup to all the sights, sounds, smells, people and other animals that you can.

-- Never let your puppy do anything you wouldn't want a grown dog to do. Puppies jumping up are cute. Dogs doing the same are not. It's always easier to prevent a problem than to try to fix it later.

-- Teach your puppy using positive methods, and make training fun! The dog-training world has made great strides in developing positive training techniques. Find a book, a tape, a class -- or all three -- that will help you make the most of these exciting new ways to train. And don't overlook a puppy class: They're great for socialization.

-- Realize your puppy will make mistakes, and don't get angry when he does. Puppies are babies! Don't expect perfection and don't be heavy-handed. It's better to distract and redirect puppies than to punish them.

Love your puppy, play with your puppy, enjoy your puppy. But you should always -- always -- be thinking of how you're molding this little baby into the confident, obedient dog of your dreams. Time passes all too quickly in the life a puppy. A couple of critical weeks, once past, are gone forever. So take the time. Make the effort. And don't delay.

Next week I'll give you some tips for house-training that pup.

PETS ON THE WEB

Still struggling with a name? Try the Web site A Zillion Puppy Dog Names (www.puppyshop.com/names/names.htm). Not a zillion, whatever that is, but a respectable amount, in several different categories such as "double names" (Cloak and Dagger), triple names (April, May and June), and names by country of origin (German names for German breeds, Irish names for Irish breeds and so on). Don't forget checking out name books for human babies, too. I have quite a few of them, including a dog-eared one I bought when 13-year-old Andy joined my family. He came within a hair's breadth of being named "Robin," as the scribbles in the margin clearly reveal.

THE SCOOP

Who knows what pets like to listen to? At the Best Friends Animal Sanctuary in Kanab, Utah, they play New Age music for their feline residents. The natural sounds -- such as those of birds -- keep them entertained, they say. I don't know about that, but I can vouch that the three-CD set of "Pet Music" kept me entertained. Marketed to reduce pet stress and separation anxiety, the collection offers more than three hours of soothing sounds, a nice mix of instrumentals and nature. You can find the collection for $19.99 (and often less) at pet-supply stores, in catalogs or from online retailers.

QUESTIONS FROM THE PACK

Q: I have a puppy who was born with his back legs paralyzed. He is in need of a dog wheelchair. I have seen a device on TV that lets a dog roam free, but no one has said how to get one. My puppy is suffering. You may have information I cannot get my hands on. Please help. -- D.P., via e-mail

A: The K9 Cart Co. has been making this product for more than 30 years, saving the lives of hundreds of dogs. The carts support and gently cradle the hind end of impaired dogs and allow them to propel themselves forward with their front legs. Prices for the custom-built carts range from $220 to $430 (extra for options such as mountain bike tires for more active dogs). To reach K9 Carts, call 1-800-578-6960, or visit the Web at www.k9carts.com.

You will run into people who will question your decision to put your dog into such a device. Some will think it's silly, or even disgusting, and some will even think it's cruel. That's their problem! Don't let the naysayers dissuade you. I have met a few dogs who use carts for mobility, and they have led happy lives and continue to bring joy into the lives of their human caretakers. Caring for such a dog requires a greater level of commitment, but if you are up to the challenge, let your heart be your guide.

Q: My Siamese cat is ruining my sweaters! She chews big holes in them, and I can't stand to lose any more. How can I get her to stop? - H.M., via e-mail

A: Some cats like to chew and suck on clothes, especially wool sweaters -- a problem behaviorists call wool-chewing or fabric chewing, since some cats are just as fond of cotton or other fabrics. This destructive habit was originally thought to be associated with cats who'd been weaned too young, but now behaviorists believe that the tendency is genetic and more common in some breeds or mixes than in others. The primary culprits are Siamese and other so-called "Oriental" breeds such as the Burmese. No one knows why these breeds and mixes are more likely than others to indulge in this habit.

Increasing fiber in the diet by adding a teaspoon of canned pumpkin daily eases these tendencies, as may offering substitute chew articles such as sheepskin-covered dog toys. Regular, active play sessions will rid your cat of some of her excess energy. A veterinary behaviorist may also be able to help, with the prescribing of anti-obsessive medication and the development of a specific behavior-modification program for your pet. It's a cheaper option than a drawer full of sweaters, that's for sure!

Cheaper still is changing your own behavior. Keep the objects of your cat's obsession out of reach in closed hampers or drawers.

Gina Spadafori is the award-winning author of "Dogs for Dummies," "Cats for Dummies" and "Birds for Dummies." She is also affiliated with the Veterinary Information Network Inc., an international online service for veterinary professionals. Write to her in care of this newspaper, or send e-mail to writetogina(at)spadafori.com.

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