Scientifically, dogs are carnivores, but as with wild canines, they are also scavengers.
How many times on a walk or even in the backyard has your dog picked up and eaten something so disgusting you were horrified? Yes, whether we consider it food or not, dogs will eat just about anything—and our human food is easy pickings.
Most dogs, especially puppies and teenagers who haven't been taught any better, won't hesitate to steal food off the kitchen counter, table, coffee table or picnic table outside. Your dog doesn't see a problem with this; it's good food that has been left unattended and is within reach. Eating it is what a scavenger does.
Just because stealing food is natural, though, doesn't mean we have to accept it. Your dog can learn to leave your food alone.
It's Not Going to Be Easy
Food stealing, or as some dog trainers refer to it, counter surfing, is a self-rewarding behavior. When your dog grabs your roast beef sandwich and gulps it down, the roast beef sandwich becomes the reward. A really strong reward, to be honest.
If the first time your dog grabbed something off the kitchen counter he got some food that was distasteful to him, perhaps a bowl with cut lemons and lemon juice, for example, he might never steal food again. However, every time your dog steals food and the food becomes a reward, the chances of him doing it again are increased. Because of this, changing this habit is going to be a challenge, but doesn't mean you shouldn't try.
It's going to be important to make sure there is nothing your dog can steal. Put away the groceries when you come home from the store; don't leave food out to put away later. After meals, put away all leftovers and rinse the dishes and put them in the dishwasher. Don't store foods on the counter. Don't let dogs lick dirty dishes.
When you practice prevention you reduce the chances to steal food. His habit then is not constantly being reinforced.
This also applies to anything that might be considered food. Put away your decorative food (a fruit basket), the cat's food, and even any dog food being stored on the counter or within reach. Don't forget meat thawing in the kitchen sink and the bread on the counter.
Teach "Leave It"
Many trainers teach an obedience exercise called "leave it." In fact, it's such a useful exercise that although rarely taught 20 years ago, now it's become one of the basic obedience exercises.
"Leave it" means "ignore." So, if you wanted your dog to ignore your neighbor's dogs who are barking behind a fence, as you walk past you could tell your dog, "Leave it. Watch me!" In other words, "Ignore those dogs and focus on me."
There are many ways to teach "leave it" depending on the training method you are used to. If you've started teaching this exercise, refresh your dog's skills. If you haven't taught it, call your local trainer for some help.
Once your dog understands leave it and is doing well, begin using your food as the object to be ignored. With your dog on leash, place a roast beef sandwich on the coffee table, and tell your dog to leave it. Practice this with different items of food in different places.
Ignoring Your Food All the Time
Once you have taught the leave it and practiced it, your dog will hopefully understand that when you say he must ignore the food, he should do exactly that. In your dog's mind, however, if you haven't said that he's to leave it, the food is then fair game. So now you need to expand the concept.
Put a leash on your dog and let him drag it. Place a bit of food on the coffee table. Walk him past the food. If he looks at it tell him to leave it. Praise and reward him when he does. If the second time past he looks at you and ignores the food, enthusiastically praise and reward him.
Pretend to be distracted but keep an eye on your dog. When he looks at the food, and hopefully before he nabs it, tell him to leave it. If he ignores the food, especially without you having to say anything, praise and reward him.
Over a number of training sessions, vary the food you use and where the food is located. Be enthusiastic and generous with rewards for ignoring the food.
Talk to Your Veterinarian
If your dog just can't ignore the food, even with training, then talk to your veterinarian. Some health issues and medications make a dog ravenous and if he thinks he's starving then all the training in the world won't change anything. Explain to your vet what the dog has been doing, what you've been doing as far as prevention and training, and let your veterinarian help you figure out if anything else could be causing the problem.