hookworms in dogs
The hookworm is a parasitic nematode. It lives in the small intestine of its host. The hosts may be mammals such as cats, dogs or humans. Ancylostoma duodenale and Necator americanus are two types of hookworms that infect humans. It is thought that hookworms infect more than 600 million people around the world. The A. braziliense infect the cats and A. caninum infects the dogs. The Uncinaria stenocephala infects both the dogs and the cats.
Morphology of hookworms
Deudenale worms are slight pink or grayish white 9n colour. In relation to the body, their head is a bit bent. This bend forms a shape of hook at the anterior end. Thus it has been named hookworms. They have a well developed mouth. They also have two pairs of teeth. The female worms are often longer and stouter than the male worms. Based on the presence of prominent posterior copulatory bursa, the male and female worms can be separately identified. Ancylostoma duodenale and Necator americanus are very alike in morphology. The Necator americanus are a bit smaller than the A. deudenale.The Necator americanus has one pair of cutting plates in the buccal capsule. Furthermore the Necator americanus has a more definite shape of hook than the Ancylostoma duodenale.
Pathology of hookworms
It is generally considered that hookworm infections are asymptomatic. There are some specific symptoms a person may experience soon after being infected. Ground itch, cough and pneumonitis, diarrhea and gastrointestinal discomfort, intestinal blood loss, iron deficiency anemia, protein malnutrition etc. There are many other outcomes of hookworm infections that play a very important role in public health. Children may suffer from growth retardation, intellectual and cognitive impairment because of chronic hookworm infections. Because of worm infections in tissues, it is often seen that eosinophils, a type of white blood grows in large numbers. In cases of prolonged infections, the hemoglobin level in blood will be seen falling.
Life cycle of hookworms
The hookworms primarily exist in sandy or loamy soil. They cannot live in muck or in clay. The average rainfall must be over 1cm/year. The eggs can only hatch in such conditions. The hookworms normally live only for a few weeks under natural conditions. But they die almost immediately under direct sunlight or in desiccation. The larva infects the host not the eggs. The usual method of infection is through skin of the foot.
After entering the body, they migrate to the lungs through vascular system. Then they come up from trachea and get swallowed. Then they enter the digestive system passing the esophagus. Thus their journey ends and the larvae mature into adult worms. After entering the host guts, the Necator americanus causes prolonged infection. Their time line is generally 1-5 years, but there are records that some lived up to 15 years. On the contrary, the Ancylostoma duodenale lives for a short time. Their average surviving time is about 6 months. But the infection can be prolonged as dormant larvae can be recruited from tissue stores for many years. The female worms lay up to 30,000 eggs per day. This way the life cycle of hookworm completes.