Puppy Deworming Schedule: When and How Often

Why nearly every puppy is dewormed

Roundworms are so common in puppies that vets treat every puppy as if infected. The Companion Animal Parasite Council explains that the larvae lie dormant in the mother's tissues, wake up late in pregnancy and cross the placenta, so many puppies are born already carrying worms. More can be picked up from contaminated soil or the mother's environment.

Dewormers act on adult worms in the gut, not the larvae still traveling through the body, and new larvae mature in about three to four weeks. That is why one dose is never enough and treatments are repeated every couple of weeks while a puppy is young.

The typical puppy deworming schedule

CAPC recommends starting at 2 weeks of age and repeating every 2 weeks, commonly at 2, 4, 6 and 8 weeks, until the puppy is started on a monthly broad-spectrum parasite preventive. The AKC describes the same pattern, noting that some products have weight limits, so a very small puppy's first dose may wait until closer to 3 weeks.

A responsible breeder or rescue should have started this before your puppy comes home, so ask for the dates and products used. Bring those records to your first vet visit at 6 to 8 weeks, where your vet will continue the schedule, often alongside the first vaccines.

After 8 weeks: monthly prevention

Once the initial series is done, most puppies move to a monthly product prescribed by the vet. Many heartworm preventives also control roundworms and hookworms, and some cover other parasites, so one product may do several jobs. Your vet will match it to your puppy's weight and your region.

Because these products are dosed by weight, the right product changes as your puppy grows. Recheck the weight band at each visit. Never split or share products between pets, and never use a dog product on a cat or the reverse.

Stool tests in the first year

Routine deworming does not catch everything. Some parasites, such as coccidia and giardia, need different treatment, and a single negative test does not rule worms out. CAPC advises testing puppies' stool at least four times in the first year, then at least twice a year for adults.

Bring a fresh stool sample, ideally from the last 12 hours, in a sealed bag or container. Older samples dry out, which makes some parasites harder to find. Your vet may use a standard flotation test and, in some cases, antigen tests that pick up infections with few eggs.

Picking up after your puppy promptly with poop bags or a pooper scooper reduces the chance of worm eggs building up in your yard.

Signs your puppy may have worms

Some puppies with worms look completely normal. Others show a pot belly, a dull coat, poor growth, diarrhea, vomiting, or worms in stool or vomit; roundworms look like thin spaghetti, and tapeworm segments look like grains of rice around the tail. Hookworms feed on blood and can cause anemia, with pale gums and weakness, which can be serious in a small puppy.

Call your vet if your puppy has diarrhea for more than a day, any blood in the stool, pale gums, or seems lethargic or stops eating. In a puppy who has not finished its vaccines, any diarrhea is worth a call, since parvovirus can look similar early on.

Protecting your family

Roundworm and hookworm eggs and larvae can infect people, children most of all, usually through contaminated soil in yards, sandboxes and playgrounds. Prompt deworming is part of protecting your household, not just your puppy.

Pick up poop promptly, ideally the same day, wash hands after handling your puppy or cleaning up, cover sandboxes, and teach children not to put dirt in their mouths. Keep fleas under control too, since dogs pick up tapeworms by swallowing infected fleas while grooming.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.