How to treat a dog with worms

a dog with worms
(Image credit: Getty Images)

Dealing with a dog with worms can be gross, but it’s unfortunately a common occurrence and there’s nothing quite as appalling as finding a wriggling worm in your dog’s stool! . Puppies are especially susceptible to parasites, but dogs of any age can be affected. Your dog may contract parasites from coming into contact with the feces of other dogs, eating wildlife or their feces, or even through contact with infected soil. Organizations like the Companion Animal Parasite Council (CAPC) and the American Veterinary Medical Association (AVMA) recommend keeping your dog on parasite prevention medications year-round to combat this issue. If your dog has had some gaps in his parasite prevention, you may need to follow these guidelines to treat your dog for worms.

Signs of intestinal parasites in dogs

How do you know if your dog has worms? Many dogs with parasite infections show no symptoms at all. That’s why it’s so important to see your veterinarian for regular preventive care and fecal screenings. When dogs do show symptoms of parasitic infections, these signs can include:

  • Diarrhea
  • Vomiting
  • Decreased appetite
  • Poor quality hair coat
  • Worms in the stool or vomitus
  • Coughing
  • Weakness
  • Lethargy
  • Weight loss or failure to gain weight
  • Pot-bellied appearance
  • Dog scooting

Many of these signs can also occur with other illnesses, some of which may be serious. So it’s important to consult your veterinarian about any changes in your dog’s health or behavior. Never give your dog any over-the-counter medications or home remedies unless your veterinarian has advised you to do so. Many of these treatments can be harmful to dogs, especially if the underlying cause of their symptoms has not been correctly diagnosed.

See your veterinarian to diagnose the problem

If you suspect your dog may have worms or other intestinal parasites, the first step is a visit to your veterinarian. There are many internal parasites that can affect dogs and not all parasitic infections are treated the same way. Your veterinarian may recommend evaluating a sample of your dog’s feces to find and identify parasites. Sometimes a fecal sample can provide a false negative result, due to the intermittent shedding of parasite eggs in your dog’s feces. If your dog’s symptoms continue, your veterinarian may recommend testing additional fecal samples. If your dog has a known history of exposure to parasites, your vet may instead recommend a prophylactic deworming, which means giving your dog a broad spectrum deworming medication to treat the most common culprits. Common intestinal parasites in dogs can include hookworms, roundworms, whipworms, coccidia, and giardia, among others.

Treating a dog with worms

The types of parasites your dog is exposed to may vary depending on your geographic region, the season, and your dog’s age and lifestyle, so your veterinarian will choose a deworming medication with these factors in mind. Some medications may need to be given only once, while others may need to be repeated for multiple days or at regular intervals in order to fully address the infection. If parasites are prevalent in your area or if your dog has a high risk of exposure, your veterinarian may recommend treating your dog with a broad spectrum dewormer monthly to prevent both heartworm disease and intestinal parasites.

When treating a dog with worms, it is especially important to treat the dog’s environment. Dogs can easily re-infect themselves or infect other dogs with the parasite eggs that are shed in their feces. Any time your dog defecates, be sure to pick up the feces right away and dispose of it in a sanitary location. Avoid walking your dog in areas where other dogs or wildlife defecate. Many parasites that affect dogs can also infect humans, so practice good hygiene and always wash your hands after handling your dog’s feces. Young children are particularly susceptible to parasitic infections and should not be allowed to play or walk barefoot in the areas where dogs routinely defecate.  

a dog with worms

(Image credit: Getty Images)

Preventing worms in dogs

You know the old saying: “An ounce of prevention is worth a pound of cure!” Parasite infections are much easier to prevent than they are to treat. Veterinarians typically recommend treating your dog with a monthly broad spectrum anti-parasitic medication, which will protect your dog against heartworm and intestinal parasites. Keeping your dog up-to-date on flea and tick preventive medications is also important, because fleas can transmit tapeworms, a common intestinal parasite of both dogs and cats. In addition to preventive medications, your veterinarian may recommend annual or semi-annual testing to screen your dog for parasites. Many dogs with worms are asymptomatic, so this is an important step to catch infections early and identify any gaps in your dogs’ preventive coverage.

Young puppies are especially susceptible to worms due to their immature immune systems. Parasites like hookworm can be transmitted from the mother dog to her puppies while they are still in the womb. Puppies can also acquire parasites when nursing from their mother or from contact with an unsanitary environment. If you’ve adopted a new puppy, make sure you ask your veterinarian about the best deworming schedule based on your puppy’s age and overall health. Most puppies will receive multiple doses of a broad spectrum dewormer during their first few months of life to ensure they have not contracted any parasites from their mother.


Worms are a common problem in dogs, but that doesn’t mean you’ll have to deal with worms forever! With appropriate treatment prescribed by your veterinarian, good sanitation, and preventive medications, your dog will be worm-free and back to his old self. Ask your veterinarian for the best products to help prevent and treat worms in a dog.

Elizabeth Racine, DVM

Dr. Elizabeth Racine is a small animal general practice vet covering all things pet health and wellness.  Her special interests include veterinary behavior, nutrition, and internal medicine.  As a freelance writer, Dr. Racine has written content for major companies in the industry such as the American Kennel Club, Merck Animal Health, Bayer PetBasics, Elanco, and CareCredit.  In her free time, Dr. Racine enjoys playing trampoline dodgeball, hiking with her beagle Dasher, and spending time with her three mischievous cats.