How Do You De-worm Dogs and Puppies?

Medically Reviewed by Amy Flowers, DVM on November 09, 2022
4 min read

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 their 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.

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. They'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 ,  a shot or use a topical dewormer (like Advantix, or Revolution) 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.

Because worms are so common in puppies, vets recommend de-worming them for the first time when they're 2 to 3 weeks old. Worms can pass from mother to baby before birth or soon after, through their milk. It will take more than one dose. The first round kills the worms that are there at the time. The second kills those that hatch a few weeks later. Rarely, your vet may want to give your puppy blood, because hookworms drain blood from the wall of the intestines, which can cause anemia.

Treatment is much the same for adult dogs with worms. The same kinds of drugs are used, but your dog will get more of the medicine.

If your dog has heartworms, your vet will need to do blood work, take X-rays, and maybe do other tests to see how serious the infection is. Just the tests can cost $1,000 or more, but they're necessary. Initially, your dog will be started on monthly heartworm prevention along with an antibiotic and anti-inflammatory. A month later, the heartworm treatment starts. This is a strong medicine that should only be given by a vet. Typically, your dog gets a series of three shots over a 2-month period.

But that’s not the end of the treatment. You'll need to keep your dog calm and quiet for several months after the shots. When heartworms die they break into pieces. These chunks can block blood from flowing to the heart or lungs. When that happens -- and there is a greater chance when blood pumps harder, such as during exercise -- a dog could die. Your vet will give you tips to make sure your sick dog gets rest so they can recover safely.

Nine months after the heartworm treatment, your vet will do a blood test to check for worms. If they're still there, your dog will need another round of shots. If they're all gone, you continue the preventive medicine for the rest of your dog’s life and test for heartworms each year.

The best way to protect your pet is to control the pests that carry worms, including fleas and mosquitoes, and keep your home and yard clean. You'll be doing yourself a favor, too, because some types of worms can be passed to humans.

Follow these simple steps to ward off worms:

  • Make sure your vet checks your dog for all kinds of worms at least once a year (two to four times for puppies).
  • Keep your dog flea-free. You can buy flea collars or medicine to put on your dog’s skin. There are also flea control treatments that you can give to your dog by mouth.
  • Get a prescription from your vet for the drug to prevent heartworms, and give it to your dog once a month. Never skip a dose. Ask your vet about a heartworm prevention drug that can be injected every six or twelve months. 
  • Practice the four Ps: Pick up (and throw away) Pet Poop Promptly. Clear your yard at least weekly and scoop up after your dog when you go for a walk.
  • Wash your hands often, including after you pet animals and especially after picking up their waste.

If you’re worried about catching worms from dogs, don't let them lick or kiss you or your kids. And make them sleep on their own bed -- not yours.