Hookworm in Dogs: Signs, Treatment & Prevention

Hookworms can lead to gastrointestinal upset in otherwise healthy adult dogs but can be fatal for puppies. In this post, our Redmond vets discuss hookworms in dogs, including the causes, signs, and treatment options.

Hookworms in Dogs

Hookworms are intestinal parasites with hook-like mouthparts that are commonly seen in both cats and dogs. Although they are only about 1/4" - 3/4" in size once they latch onto your pet's intestine they can ingest surprisingly large amounts of blood.

If your pet is infected with a significant number of hookworms they could develop inflammation of the intestine or anemia.

Hookworms are most often seen in warm, moist environments and in pets that live in poor conditions involving overcrowding or poor sanitation.

Causes of Hookworms in Dogs

Dogs become infected with hookworms in one of four ways:

• Unborn puppies can contract hookworms through the mother's placenta in utero.
• Once born, puppies can contract hookworms through their infected mother's milk.
• Your dog could quickly ingest hookworm larvae by sniffing at contaminated feces or soil, or when grooming their feet.
• Larvae can penetrate your dog's skin leading to infection.

Lifecycle of Hookworms

There are three stages in the hookworm lifecycle: egg, larvae, and adult.

• The microscopic eggs are laid by the adults within an infected pet. The eggs are then passed through the feces, where they hatch into larvae and contaminate the environment.
• The larvae can survive for weeks or even months before infecting an unsuspecting dog.
• Once the larvae enter your pup's body they migrate to the intestine, where they mature into adults and lay eggs - starting the cycle all over again.

Symptoms of Hookworms in Dogs

Intestinal upset is the primary symptom of hookworms in dogs. Other symptoms can include:

If your dog is showing any of the signs of hookworms listed above, contact your vet right away. It is not uncommon for young puppies to die from severe hookworm infections.

Diagnosing Hookworms

Hookworms are easy to diagnose through a fecal flotation test. 

Your vet will request that you bring in a fresh stool sample from your dog. The stool will be mixed with a solution that will cause the eggs (if present) to float to the top of the solution where they can easily be spotted.

However, this test is only accurate once the worms have matured enough to begin producing eggs. Unlike some other worms seen in dogs, you will not typically see hookworms in your dog's poop because the worms stay securely latched onto your pet's intestinal lining until the condition is treated.

It takes 2-3 weeks for worms to reach maturity and begin producing eggs, for this reason, fecal floats may not be accurate in diagnosing hookworms in very young puppies.

Treatment of Hookworms in Dogs

A class of drugs called anthelmintics can be used to eliminate hookworms. These medications are typically given orally and rarely produce side effects. That said, these medications are only effective at killing adult hookworms so it will be necessary to repeat the treatment 2-3 weeks following the first treatment.

If your dog is suffering from severe anemia due to hookworms, a blood transfusion may be necessary to save your dog's life.

Hookworm Transmissibility to Humans

Lying on a hookworm-infected surface can allow the hookworm larvae to begin burrowing into the skin, leading to a condition called 'ground itch'.

In some rare cases, hookworm larvae can penetrate and damage internal organs including the eyes, which can cause blindness and complications. Good bathing and hygiene habits can help to prevent hookworm infections in people.

Preventing Hookworms in Dogs

There are several key approaches when it comes to preventing the spread of hookworms in dogs:

• Keep your dog up-to-date on their parasite prevention. Many products formulated to prevent heartworm will also help to prevent hookworm.
• Puppies should be dewormed at approximately 2-3 weeks of age, and if symptoms occur.
• Nursing female dogs should be dewormed when their puppies are also dewormed.
• Always clean up after your dog when at the park or out on walks, and keep your yard free of dog waste.
• Be sure to wash your hands frequently when around your dog, or after cleaning up dog waste. Also, ensure that your children wash their hands frequently.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical or behavioral advice regarding pets. Please make an appointment with your vet for an accurate diagnosis of your pet's condition.