Signs of Worms in Dogs: What to Look For and What to Do

Intestinal worms are remarkably common in dogs — but they're not always easy to spot. Some dogs show obvious symptoms; others harbor parasites for months with no visible signs while quietly shedding eggs that can even infect their human family members. Knowing what to look for and keeping up with prevention can protect your whole household.

Types of Worms That Affect Dogs

Roundworms (Toxocara canis)

The most common intestinal parasite in dogs, roundworms are especially prevalent in puppies — they can be passed from mother to pup through the placenta or milk. Adult dogs usually have some immunity but can still be infected. Roundworms look like spaghetti and may be visible in vomit or feces.

Hookworms

Hookworms attach to the intestinal wall and feed on blood. In puppies, they can cause life-threatening anemia. They can also penetrate human skin (called cutaneous larva migrans), making them a public health concern.

Tapeworms

Tapeworms are contracted by ingesting infected fleas or by eating raw/undercooked meat. They shed segments that look like grains of rice or sesame seeds — you may see them in the dog's feces or stuck to the fur around the anus.

Whipworms

Whipworms live in the large intestine and cause chronic diarrhea, weight loss, and anemia. They can be difficult to diagnose because they shed eggs intermittently.

Heartworms

Heartworms are transmitted by mosquito bites and live in the heart and major blood vessels — not the intestines. They're covered separately, but it's worth noting that heartworm prevention medication also covers most intestinal worms.

Signs of Worms in Dogs

Symptoms vary by the type of worm and the severity of infection, but common signs include:

• Visible worms in feces or vomit (spaghetti-like roundworms) or worm segments around the anus (tapeworm segments)
• Pot-bellied appearance, especially in puppies (classic roundworm sign)
• Scooting — dragging the rear end along the ground (often tapeworms causing irritation)
• Diarrhea — sometimes bloody (hookworms, whipworms)
• Weight loss despite a normal or increased appetite
• Vomiting — sometimes containing visible worms
• Dull, dry coat — a sign of poor nutrient absorption
• Lethargy and weakness
• Pale gums — indicating anemia from blood-sucking worms like hookworms

Many dogs, particularly adults with mild infections, show no visible symptoms at all — which is why regular fecal testing is important.

When to See a Vet

• You see visible worms in feces or vomit
• Puppy with a swollen belly, pale gums, or bloody diarrhea (potentially urgent)
• Unexplained weight loss or chronic diarrhea
• Dog is scooting and the anal glands have been ruled out
• It's been more than 6–12 months since a fecal test

What To Do

1. Bring a fresh fecal sample to your vet — a stool test identifies which parasite(s) are present.
2. Don't use over-the-counter dewormers without guidance — different worms require different medications, and OTC options often don't cover all types.
3. Follow your vet's deworming protocol — most puppies are dewormed on a schedule starting at 2 weeks old.
4. Keep your dog on monthly heartworm prevention — many heartworm preventives also protect against roundworms, hookworms, and whipworms.
5. Clean up feces promptly from your yard to reduce environmental contamination.
6. Wash hands after handling dog waste — roundworms and hookworms can infect humans.

Protecting Your Family: Zoonotic Risk

Several canine parasites pose a real public health risk — especially to children who play in soil:

• Roundworms (Toxocara canis) can cause visceral larva migrans in humans, with larvae migrating through organs including the liver, lungs, and even the eyes. Ocular larva migrans can cause permanent vision damage in children.
• Hookworms cause cutaneous larva migrans — an itchy, winding skin rash from larvae burrowing beneath the surface.

These risks are well-managed through regular deworming, handwashing after handling soil or dog waste, and keeping children away from areas where stray dogs defecate.

How Voyage Can Help

Worried about worms but not sure if your dog's symptoms add up? Voyage AI Vet can help you think through what you're seeing and whether a vet visit is urgent. Available anytime, starting at $4.99/month — no appointment needed.

This article is for informational purposes only and is not a substitute for professional veterinary advice. Regular fecal testing and parasite prevention are the best ways to protect your dog from intestinal parasites.