Dogs are ideal hosts — to worms and other parasites, that is. Animals that sniff, slurp, lick, and gobble anything in their paths, including dirt, trash, and poop, are bound to pick up pests. All the things they do with their mouths — groom, kiss, wrestle, and other social habits — can pass along unwanted guests to playmates and companions, canine and human alike.

Parasites worm their way into most dogs’ lives at one time or another. Your vet may suspect worms if your dog has diarrhea or is vomiting, coughing, chewing or licking under his tail, short of breath, or losing weight. The symptoms and treatments depend on the type of worm and where it’s living in your dog’s body.

Confirm the Worm

Most worms that infect dogs — including roundworms, tapeworms, hookworms, and whipworms — live in the intestines, so that’s the first place for your vet to look.

If it’s time for your dog’s annual check-up, or if you or your vet thinks your dog has worms, provide a fresh stool sample. Simply scoop up some of your pet’s poop, seal it in a clean plastic bag, and bring it to the appointment. If you can’t do that, your vet can take a sample during the office visit. He’ll check it under a microscope to see if it has worms or worm eggs, and, if so, what kind.

Heartworms are another type of canine invader that can cause serious health problems or sometimes even death. These foot-long worms live in the heart, lungs, and blood vessels. Mosquitoes carry the worms’ offspring from one dog’s blood to another’s. The vet will do a blood test to tell if your dog has heartworms.

There are many safe ways to de-worm your dog. The sooner the worms are gone, the sooner your pet will get healthy and feel better.

Your vet will give your dog medicine by mouth or in a shot to kill the worms. Many of these drugs are described as “broad-spectrum,” because they’re good for treating a wide range of parasites, including worms that live in the gut. They’re poisonous to pests, but safe for pets.