Introduction
Hookworms are parasites in the genus Ancylostoma, which in their adult and 4th-larval stages live and breed inside of the intestines of companion animals. They are voracious blood feeders, and they attach (or “hook”) onto the intestinal lining of dogs and cats, causing blood loss and subsequent anemia. Hookworms can cause severe illness, and they can be especially lethal to young puppies who acquire the parasite by transmammary infection – that is, from the milk of their mother. The clinical signs that dogs experience from hookworms are primarily caused by this severe loss of blood.
Symptoms of Hookworm Infestation
Newborn puppies infected with hookworms usually present with acute disease. They often are healthy in the first week of life, but then deteriorate rapidly in their second week, with severe anemia from blood loss, soft tarry and bloody stools, diarrhea, weakness, pale mucous membranes and possibly even sudden death. This can happen even before the eggs of the hookworms can be detected through a fecal examination done by your veterinarian.
Mature dogs and older puppies normally present with signs of more chronic anemia from infestation with a large number of hookworm larva. Some of the most common signs of chronic hookworm infection include weakness, tarry/dark stools, pale gums and lethargy. If the hookworm infection is not treated, the dog’s coat can become affected; the fur may begin to thin, the skin can become dry and flaky, and the coat can lose its healthy luster. Over time, affected dogs may loose weight and appear emaciated, but their stomachs at the same time can appear bloated or swollen. Severe hookworm infections cause anemia, which is what causes the symptoms of pale gums, weakness and potential collapse.
Any type of parasitic infection requires prompt treatment. Untreated hookworm infections can lead to stunted growth in puppies, depression, developmental abnormalities and even death. If you notice any of the above symptoms in your dog – especially in a new puppy - please schedule an appointment with your veterinarian as soon as possible. Your veterinarian will probably perform a fecal test to look for eggs of the parasite in order to diagnose what type of parasite, if any, your dog is carrying.