How to Deworm a Dog

Worms or parasites are one of the more common problems encountered in canine veterinary practice. Several different types of worms may be seen in dogs and puppies: roundworms, hookworms, tapeworms, whipworms, and coccidia. Your veterinarian can recommend an appropriate dewormer for your dog depending on the type of worms your pet has. This is best determined by having your veterinarian examine a stool sample. Always consult with your veterinarian before giving you dog or puppy a wormer, even an over-the-counter one.

Worming schedules will vary depending on the product and your dog's age, as mentioned below, regarding Pyrantel in young puppies. Typically puppies will be treated every two to three weeks for two or three treatments to ensure elimination of roundworms and hookworms. Adult dogs are typically wormed when specific parasites are found on microscopic exam of stool samples, except in cases of bloody diarrhea where whipworms are suspected, since these parasites are difficult to diagnose on many stool samples. Monthly heartworm preventatives will often be effective in killing other parasites such as hookworms and roundworms, as well as in preventing whipworms. Veterinarians usually won't worm pregnant dogs until after delivery, since most puppies will be born with roundworms no matter how often adult pets are wormed.

Dewormers for dogs

Several worming medicines are available for dogs. These products differ based on which worms need to be eliminated from your pet. The most common worm medications used in young puppies contain Pyrantel, which is found in Drontal Plus. Usually, two doses of Pyrantel are recommended for puppies at three and six weeks old to treat and prevent roundworms and hookworms, which are most common in puppies this age.

Another common wormer used mainly for adult dogs and/or those with whipworms is the wormer Panacur C, which also treats giardia parasites. This wormer is typically given for three to five days and readily mixed with food. This is often veterinarians' first choice if whipworms are suspected, even if intestinal parasites are not found in a fecal exam. Praziquantel (found in Drontal Plus and Droncit) is effective for removing tapeworms, which are not as easily killed by other wormers. When treating coccidia in puppies, Albon Tabs or Albon Suspension are often the first choice.

Types of worms found in dogs and puppies

A large percentage of puppies are born with roundworms or ascarids in their tissues. These larvae are introduced to the developing puppy either through the mother's milk or in the mother's uterus before being born. Roundworms are most commonly found in puppies and may cause varying amounts of diarrhea, vomiting, and weight loss, often with an increased appetite. Some dogs will develop a bloated abdomen with roundworms or other types of worms. On occasion, dogs may even vomit up visible roundworms as well.


Hookworms are small, thin worms that attach to the wall of the small intestine and suck blood. Severe hookworm infestations may even kill puppies, as these worms can make puppies severely anemic. In older dogs, chronic hookworm infection may cause low stamina, decreased appetite, and weight loss. Other symptoms of hookworms in dogs include bloody diarrhea, anemia, and weakness.


Another common worm seen in dogs, tapeworms typically infect dogs that ingest fleas, or eat wildlife and rodents. In many cases, tapeworms cause no severe clinical symptoms, but are often diagnosed by finding tapeworm segments in the stool or near the rectum of affected dogs.


Whipworms are thread-like worms which typically live in the large intestines of dogs, and may cause symptoms such as mucousy or bloody stool, low appetite, and weight loss. These worms also suck blood and cause anemia. Whipworms are difficult to diagnose, as a microscopic exam of several fecal samples may be necessary to detect them. Whipworms can also be one of the most difficult worms to eliminate but they are both treatable and preventable.


Coccidia are intestinal parasites that overgrow typically in young puppies from boarding or pet store facilities, and may cause varying degrees of diarrhea, often with blood. Coccidia are not as readily seen in adult dogs, since they seem to have a more innate immunity to these parasites.

Consult your veterinarian

Dog owners should always consult their veterinarians before using any worming product. Some breeds are sensitive to some products, such as herding breeds (Australian Shephards or Collies). Ivermectin, found in Iverhart Plus, can sometimes cause serious reactions in these breeds. Your veterinarian is often the best source of information on which products to use and how often wormers should be used in dogs.

Pharmacy Tip

A microscopic stool check should be done at your veterinary clinic to properly identify which worms are present in your dog.