The first step in turning an adult dog into a reliable house pet is to embrace a key concept: There's no such thing as a "partially" house-trained dog. It either is or it isn't.

Why is realizing this important? Because if you have a dog who is "sometimes" reliable, you have a dog that doesn't understand what's required of it, probably because no one taught it properly in the first place.

Punishing your pet isn't fair and it isn't the answer: You have to go back to square one and teach it properly. No shortcuts here.

Before you start training, though, you must be sure that what you have is really a behavior problem and not a physical problem. This is especially true with a dog that has been reliable in the past. You won't be able to train your pet if it is struggling with an illness. So check with your veterinarian first for a complete checkup.

If you've ruled out medical problems, house training an adult dog uses the same principles as house-training a puppy, except you have to be even more diligent because you need to do some untraining, too.

And a lot of cleaning: You must thoroughly clean any soiled area with enzymatic cleaner (available through pet-supply outlets) to eliminate the smell that invites repeat business.

You'll need to teach your dog what's right before you can correct it for what's wrong. To do this, spend a couple of weeks ensuring that it has nothing but successes by never giving the dog the opportunity to make a mistake.

Here's how

• Leash the dog to you in the house so you can monitor its every move during this training period. If it starts to mess, tell the dog "no," take it outside, and give it a command for going ("go now" or even "let's hurry"). Then praise it for doing right, so it starts to understand what you want.

• Put the dog in a crate whenever it's not on leash with you. It's not unfair during training to leave it in a crate for four or five hours at a stretch – assuming, of course, it is getting regular daily exercise.

• Take the dog outside first thing in the morning, as soon as you get home from work and just before you go to bed (when you put it in its crate for the night). Always remember to give your "go" command, and praise the dog when it does as you wish. People never seem shy about punishing their dogs, but too often forget to praise them – people take it for granted that the dog should do the right thing.

Never, ever forget the praise.

If you've been consistent, your dog likely will get a good idea of what's expected within a couple of weeks, and you can start to give it a little freedom. Don't let it have the run of the house yet. Keep its area small and let it earn the house, room by room, as it proves its understanding of the house rules.

Accidents happen. If you catch the dog in the act, tell it "no," take it outside, and give it the chance to set things right. Give your "go" command and praise it if it does. Clean up the mess inside promptly and thoroughly, so the dog won't feel inclined to refresh its smell there. Don't punish it for any messes you find.

If you aren't catching the dog in the act, you're not keeping close-enough tabs on your pet. Go back to the crate and leash, and start over.

If you continue to have problems, ask your veterinarian for a referral to a veterinary behaviorist. One-on-one assistance can pinpoint the problems in your training regimen and get you both on the right track.

Pet Connection is produced by a team of pet-care experts headed by veterinarian Dr. Marty Becker and journalist Gina Spadafori. The two are also the authors of several best-selling pet-care books. E-mail them at petconnection@gmail.com or visit www.petconnection.com. Back columns: www.sacbee.com/spadafori.