Signs, Treatment, and Control: Gastrointestinal Parasites

Significant gastrointestinal parasites of dogs include roundworms, also called ascarids, and hookworms.


Roundworms can be transmitted from mother to puppy before birth, from mother to puppy while nursing, and via consumption of roundworm eggs, larvae, or a rodent or rabbit host. Signs of roundworm infection may include: diarrhea, eggs and adult worms in the feces, respiratory distress, weakness, dull and scruffy coat, swollen abdomen, and malnutrition. Adult roundworms live in the intestines, depriving the host animal of nutrients. Left to grow, roundworms may block the passageway completely. Untreated, roundworms can pose serious risks for puppies and young dogs.

Hookworms can be transmitted from mother to puppy before birth, from mother to puppy while nursing, from the environment when larvae penetrate the skin or when a dog consumeseggs, larvae or contaminated material. Signs of hookworm infection may include: weakness, weight loss, diarrhea, and pale gums. Hookworms feed by repeatedly removing small amounts of tissue from the insides of the intestinal walls of the host animal, resulting in blood loss and inflammation. Severe hookworm infection can lead to anemia, debilitation, and even death.

Roundworms and hookworms can be transmitted to humans via ingestion of contaminated material or by penetration of the skin by hookwirm larvae. Serious consequences, including stomach ache, pneumonia, skin rashes, and blindness, may result.

HEARTGARD Plus from Merial is a tasty beef chewable, given once a month. HEARTGARD Plus treats and control roundworms and hookworms in dogs as young as 6 weeks of age, when a dog may be given its very first dose. Ask your veterinarian about treating and controlling gastrointestinal parasites with HEARTGARD Plus. Pic below is of a HookWorm