Hookworms are a common intestinal parasite, especially around livestock. They are small, between ½ and ¾ inches long. Despite their individual size, Hookworms infections are a serious, mainly in puppies.

Hookworms attach to the wall of the small intestine with several teeth or a cutting plate, and feed on the dog’s blood; and they consume a lot. So much so, anemia is often caused as the dog looses red blood cells.

Besides feeding on the blood, Hookworms cause intestinal bleeding and irritation. They produce an anticoagulant to prevent blood clotting at the feeding site. When the Hookworm moves, the site continues to bleed.

Affects of Heartworm Infestion

Dogs infected with Hookworms suffer form skin irritation and weakness, and their gums will appear pale and sometimes a black soft stool will be produced. In puppies growth can be stunted and infected dogs will experience weight loss, a dulling of the coat, and will eventually die.


Diagnosis is done by finding Hookworm eggs in the fesses and is another reason regular fecal exams are important. However, Hookworm infections can become sever before these eggs become evident in the fesses. In this case, the puppy owner and veterinarian must recognize the symptoms.

Life Cycle

Hookworms have a resourceful life cycle. Adults mate and produce eggs in the intestines. These eggs pass with the fesses and are spread in the environment. After 1 to 3 weeks, the larvae hatch. These larvae can swim and crawl their way around until they come in contact with a dog.

If consumed, by licking infected soil, objects, or by drinking infected water, these larvae make their way to the intestine where they mature and produce eggs. But this is not the only way Hookworm larvae can infect a dog.

The larvae can also burrow their way through the dog’s skin or the pads of the feet. This causes severe skin irritation. Once inside the body, the larvae burrow their way around until they reach the intestine directly or reach it by traveling through the circulatory system, then to the respiratory system where they are coughed up and swallowed.

Some of these larvae stop along the way and become dormant and encyst. Later, these encysted larvae will awaken and re-infect the dog.

Encysted larvae in a pregnant female will be awakened by her hormones. Signaled by these hormones, the larvae will migrate to the uterus and mammary glands rather than the mother’s intestines. Here, they will infect the puppies by migrating through the placenta or by traveling in the milk into the puppy’s intestine.

Hookworm larvae can also make use of a transport host. The larvae can infect the transport host similarly to how they infect the main host. After being consumed by a carnivore, encysted larvae awaken and are released into the intestines.

This life cycle virtually ensures that the Hookworm will infect all members of a litter if the mother has been infected. If puppies escape the larvae in the uterus and the milk, the spread of eggs passed with their litter mate’s fesses will certainly reach un-infected puppies.

Puppies are not only especially vulnerable to Hookworms; they are also sensitive to them. Puppies are an ideal host because they produce great amounts of new blood for normal body function and to power their fast growth. The voracious appetite of the Hookworm steals the puppy’s precious nutrients and energy, causing him severe problems.


Treating a dog infected with Hookworms is done with several common wormers. These wormers do not kill encysted larva. Puppies should be treated for Hookworms and puppies at risk for infection should be treated at two weeks of age and every two weeks until 12 weeks of age. Treatment should continue monthly until six months of age.

Nursing mothers should be treated along with the puppies. Adult dogs should be monitored for symptoms and should be wormed regularly. When introducing a new Doberman to your home, he should be treated immediately then two weeks later.

Hookworms are a parasite that can also affect humans by entering the skin, often through bare feet. Although they usually do not reach the intestines and mature, then y can easily infect the skin and cause severe skin irritation. The larva can cause a condition called “cutaneous larva migrans” or “creeping eruption”. In this condition, the larvae burrow around in the skin and muscles causing soreness and red lines to appear. The larvae can also erupt through the skin causing lesions or enter the lungs and cause lung disease.

In humans, the larvae usually die after several weeks and the condition disappears.