Hookworms are parasitic nematodes that live in the small intestine of dogs and other mammals. They are thin and small, about one-quarter to one-half inch (.6 to 1.3 cm) long. Hookworms characteristically attach themselves to the intestinal wall of the host and feed on blood and tissue. They detach from one spot and move to another, leaving behind little ulcers where they have previously fed. This causes severe anemia and malnutirition in the dogs.
There are at least three different species of hookworms that can affect dogs. These are Ancylostoma caninum, Ancylostoma braziliense, Uncinaria stenocephala. They differ in the severity of the disease they cause.
When a certain species of hookworm, ancylotoma caninuma, infect the dog, the condition is called ancylostomiasis. These hookworms feed by sucking blood and tissues in the small intestine. Heavy infestation by these hookworms causes iron deficiency anemia in the host dog.
Infestation of hookworms can be a life-threatning condition, specially in puppies. A dog becomes infected with hookworm through direct skin contact with the larvae, directly ingesting hookworm eggs or larvea or through transmission of larvae from mother to the puppy. Once inside, the larvae travel to the small intestine where they mature into adults. These adults hook into (hence it's name) the intestine walls with their six sharp teeth and suck in tissue and blood. These adult hookworms mate and release eggs which are excreted to the outer environment through feces. A dog that comes into contact with contaminated soil through oral (licking) or skin contact can get infected with hookworm larvae and the cycle continues.
Hookworms suck in blood and tissue in the small intestine of the host, causing diarrhea, tarry stool, weight loss, failure to grow, poor appetite, progressive weakness, pale mucus membrane, anemia and even death. When hookworm infection occurs through skin, the affected dog suffers from severe itching and discomfort.
