Puppies and worms

Puppies born with worms
Puppies are often infected with worms, and many of these worms can also infect humans. When the puppies are born to dams that did not receive deworming medication before or during pregnancy, the odds of their having worms is nearly 100%. This is because worms resting within the dam’s body are stimulated to grow by hormones secreted during pregnancy. The hormone-stimulated worms within the dam pass through the placenta (transplacental) and into the puppies before they are born. In addition, worms are passed through the dam’s milk (transmammary) to the young.

Puppies acquire worms after birth
During the first few months of life, puppies also pick up worms from sidewalks, pet parks, and soil. Although we cannot see the worm eggs, they’re scattered over these areas and are easily picked up by puppy feet. When the pups lick their feet, or lick the soil, they ingest parasite eggs and larvae.

Some worm eggs, such as the roundworm Toxocara and the whipworm Trichuris, survive for years on sidewalks and in soil. Because a single Toxocara worm can produce over 20,000 worm eggs in a single day, and the eggs are not affected by most weather conditions, areas that have had dogs travelling over them have high concentrations of worm eggs.

Puppies also pick up worms from eating fleas, catching prey, such as mice and snails, and eating feces of other pets and farm animals.

Puppy worms infect humans causing zoonotic infections
The common worms that infect puppies are roundworms, hookworms, whipworms, and tapeworms. Humans are easily infected by rounds and hooks, and less commonly infected by tapeworms. These are called a zoonotic infection, which means infections transmitted to humans from animals.

What do worms look like?
Although worms are usually not visible in the dog’s stool, we occasionally see them passed in the stool. Roundworms and hookworms look like spaghetti. Whipworms are small and round with long, thin tails. Tapeworms are flat and can be very long or can be single short segments called proglottids. Proglottids contain tapeworm eggs. If the proglottid segments dry out, they resemble rice or sesame seeds.

We’ll cover more on puppy worms in future blogs.