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. He either is or he isn't.

Why is realizing this important? Because if you have a dog who is "sometimes" reliable, you have a dog who isn't getting the picture, probably because no one took the time to teach it to him properly in the first place. To do that, you're going to have to go back to square one.

Before you do, though, make sure you're not dealing with a sick dog. If you have a pet who was perfectly house-trained and is no longer, you must determine that what you have is really a behavior problem, not a health problem. That means you need to check with your veterinarian first.

To be fair, if you've just adopted an adult dog who seems to be urinating all the time, you should have him checked out, too, before assuming he's not house-trained. If everything is fine, you can start training him.

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

Leash him to you in the house so you can monitor his every move during his training period. If he starts to mess, correct him with a sharp "no," take him outside, give a "go" command, and praise him for doing right.

Confine him when you cannot watch him. Dogs don't like to mess where they're sleeping, and most will quickly learn to "hold it" when resting in a crate or carrier. Make sure he has a favorite chew toy to work on while he's confined, so he's less likely to be anxious or bored.

Take him outside first thing in the morning, at lunch, as soon as you get home from work and just before you go to bed, when you put him in his crate for the night. Always remember to give your "go" command when you're out with him, and praise him when he does as you wish.

The most difficult part of house-training an adult dog is your attitude toward limiting his options in such a way as to make success possible. You may not like the idea of keeping such close tabs on your dog, but bear in mind you won't need to do it forever. Crates and leashes are training tools, not lifelong crutches.

If you've been consistent, your dog will likely have a good idea of what's expected of him at the end of the two weeks, so you can start to give him a little freedom. Don't let him have the run of the house yet. Keep his area small and let him earn the house, room by room, under your supervision, as he proves his understanding of the house rules.

Accidents will happen. If you catch him in the act, correct him with a sharp "no," take him outside and give him the chance to set things right. Give your "go" command, and praise if he does. Clean up the mess promptly and thoroughly, so he won't feel so inclined to refresh his smell there.

If you aren't catching him messing, you're not keeping close enough tabs on him. Go back to the crate and leash and start over.

Consistency and patience are necessary for house-training an adult dog. If you have both, you will likely succeed. Without them, you'll have a very difficult time getting the results you're hoping for.

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.