What Kind of Worms Do Dogs Get: Types, Signs, and Treatment
What kind of worms do dogs get? More than most owners realize. The different worms in dogs range from highly visible intestinal parasites to dangerous heartworms living in the cardiovascular system. Understanding the type of worms in dogs most likely to affect your pet, recognizing common worms in dogs by their signs, and knowing which worms from dogs can spread to humans helps you take the right preventive and treatment steps year-round.
Common Types of Worms in Dogs
Roundworms
Roundworms are the most common intestinal parasites in dogs worldwide. Toxocara canis can reach 3 to 5 inches in length and are often visible in vomit or feces when present in large numbers. Puppies frequently acquire roundworms from their mother through the placenta or nursing. These are among the most significant worms from dogs that can spread to humans — a condition called toxocariasis can cause serious illness, particularly in children who ingest contaminated soil.
Signs include a pot-bellied appearance in puppies, diarrhea, vomiting, poor growth, and dull coat. Adult dogs often show no symptoms despite carrying a worm burden.
Hookworms
Hookworms are small but dangerous parasites that attach to the intestinal lining and feed on blood. They are one of the type of worms in dogs most likely to cause anemia, particularly in puppies. Hookworms can penetrate human skin through contact with contaminated soil or sand — another example of worms from dogs with zoonotic potential.
Whipworms
Whipworms live in the large intestine and cecum. They are among the different worms in dogs most difficult to diagnose because they shed eggs intermittently, meaning a single fecal test may miss them. Signs include bloody diarrhea, weight loss, and intermittent vomiting. Whipworms are resistant to common environmental disinfectants and can survive in soil for years.
Tapeworms
Tapeworms attach to the intestinal wall and shed segments that appear as rice-like pieces around the dog’s anus or in feces. The most common type — Dipylidium caninum — spreads through flea ingestion when a dog bites and swallows a flea containing tapeworm larvae. Hunting dogs can also acquire tapeworms by eating prey animals. Treating tapeworms requires addressing the flea problem simultaneously.
Heartworms
Heartworms are the most serious of common worms in dogs. Transmitted through mosquito bites, they travel to the heart and pulmonary arteries where they can reach 12 inches in length. Signs of advanced infection include coughing, exercise intolerance, and respiratory distress. Treatment is extensive and risky — prevention through monthly heartworm preventatives is far safer and less expensive. Heartworms are not among the worms from dogs transmissible to humans.
Diagnosis and Treatment
Intestinal worms are diagnosed through fecal flotation tests at a veterinary clinic. Heartworms require a blood antigen test. Because different worm species require different medications, accurate diagnosis determines the correct treatment:
- Roundworms and hookworms: pyrantel pamoate, fenbendazole, or milbemycin
- Whipworms: fenbendazole or febantel
- Tapeworms: praziquantel
- Heartworms: multi-step melarsomine protocol with strict rest requirements
Annual fecal exams and year-round heartworm prevention are the standard of care for all dogs regardless of lifestyle.
Bottom Line
What kind of worms do dogs get depends on their exposure — indoor dogs can still acquire roundworms and heartworms, while dogs with outdoor access or flea exposure face a broader range of intestinal parasites. Regular veterinary testing catches infestations before they cause significant harm, and monthly parasite preventatives eliminate the most common threats before they take hold.
