Veterinary parasite reference

Hookworms, explained clearly — from first signs to full recovery.

Hookworms are blood-feeding intestinal parasites that affect dogs, cats, horses and livestock. Learn how to recognize them, how they spread, and the treatments that actually clear them.

Blood-feeding nematode Treatable & preventable Zoonotic potential
Ancylostoma caninum
What are hookworms?

Small parasites, serious consequences

Hookworms are slender nematodes, usually under 2 cm long, that live in the small intestine. They use hook-like mouthparts to latch onto the gut lining and feed on blood. A single adult worm can draw a surprising amount of blood each day, which is why heavy infections cause anemia — and why they can be life-threatening in puppies and kittens.

Different species affect different animals: Ancylostoma caninum in dogs, Ancylostoma tubaeforme in cats, and Bunostomum species in cattle, sheep and goats. They share the same broad strategy — attach, feed, and shed eggs that contaminate the environment for the next host.

The good news: hookworms are diagnosable with a simple fecal test and treatable with well-established dewormers. The key is catching them early and following through with the full course and a clean-up of the environment.

The essentials

Three things every owner should know

01 / TRANSMISSION

How animals get them

Larvae are picked up from contaminated soil — swallowed, absorbed through the skin of the paws or belly, or passed from a mother to her young through milk.

How to break the cycle
02 / SIGNS

What to watch for

Pale gums, weakness, weight loss and dark, tarry stool point to blood loss. In young animals, signs can escalate fast, so don't wait.

See all symptoms
03 / TREATMENT

What clears them

Broad-spectrum dewormers such as fenbendazole and pyrantel kill adult worms. A repeat dose catches larvae that matured after the first round.

Compare treatments
Quick tool

Estimate a dewormer dose

Choose a product and enter your animal's weight for a fast estimate. Always confirm with your vet and the product label.

Dosage calculator

Estimate a dewormer dose

Pick the product and enter your animal's weight for an at-a-glance estimate. This is a guide only — always follow your product's label and your veterinarian's direction.

Find the right dewormer for your animal

Primacur is a vet-grade fenbendazole broad-spectrum dewormer for dogs, cats, horses and livestock, available at HorsePreRace.

Shop Primacur dewormer at HorsePreRace
A note on people. Some animal hookworm larvae can burrow into human skin and cause an itchy, winding rash called cutaneous larva migrans. It's preventable with basic hygiene — wash hands, wear shoes outdoors, and clean up pet waste promptly. If you think you've been exposed, see a physician; never treat yourself with animal medication.