By Elizabeth Parker

An enjoyable jaunt around the neighborhood with your dog can take a decidedly unpleasant turn when your beloved pet enthusiastically buries his nose in garbage, rotten food or . . . something worse. Repulsed, you wonder, what's wrong with this animal?

The answer: probably nothing. As off-putting as this behavior is to us humans, it's normal for dogs, according to Tina Cheng, DVM of the Animal Clinic of Encino, Calif. "Dogs explore their world through their noses," she says. "They want to check everything out." That includes all kinds of garbage, waste products of other dogs or animals, rotten food and dirty water.

Why They Do It
For us, one of the most upsetting behaviors is when a dog eats its own stool. But even that, say experts, is normal and not necessarily harmful. One theory maintains that dogs do this so that predators will not find evidence that they're in the area, says Dr. Cheng. When dogs eat grass, they may simply need some fiber, she adds. Eating grass is not harmful for a dog.

Another reason why a dog would eat non-food items, such as wood or even rocks (a condition called pica), is that he may have anemia, diabetes or a digestive disorder. Talk to your vet about getting your dog tested if he or she feels it is necessary.

But even if there is no underlying illness at work, it is best to prevent your dog from eating and drinking outside of the proper diet you provide.

Keep Your Dog Safe
"Your dog could pick up parasites from another dog's feces, food poisoning from rotten food and could get very sick from drinking dirty water that has antifreeze in it," says Dr. Cheng. "Whenever you're on a walk, keep a tight grip on the leash." If you visit dog parks regularly, make sure that your dog keeps up with his vet visits. "Dog parks are like nursery schools for kids," says Cheng. Your dog will be exposed to many more parasites and could pick up more diseases.

Of course, dogs can find plenty to get into at home, too. They will drink toilet water and eat out of the kitchen garbage can. Dogs can eat all kinds of objects when they're bored, as well. "I've had dogs in this office who've swallowed gloves, socks, a bouncy ball, corn on the cob, a mango pit - you name it," says Dr. Cheng. Dogs will swallow something if they can, but if an object is too big to pass through the intestines, it can cause serious injury or death. Keep all such objects away from your dog.

Dr. Cheng suggests the following tips for keeping your pet out of trouble:

• Provide high-quality dog food for meals and offer appropriate-sized chew toys
• Play with your dog often, so he's not bored
• Keep toilet seats down
• Make sure garbage cans, indoor and outdoor, are latched shut
• Always put your dog on a leash while taking a walk
• Do not let your dog drink from puddles or eat any kind of garbage

Although you cannot keep an eye on your dog all the time, it is important to take these steps so that your canine's natural instincts do not get him into trouble. "It's perfectly normal for dogs to want to sniff everything, kind of like window shopping," says Dr. Cheng. "But you always need to watch what they get into and make sure they don't eat something that could make them sick."