We have noted over the past year or two an alarming increase in intestinal parasites in our area, and particularly in Hookworms. We're not entirely sure why this is happening. It may be due to milder winters, an increased resistance of the worms to the medications used to kill them, or maybe the higher number of pets being adopted into our state from Southern states.
Here is a quick review of the lifestyle of this parasite:
Hookworms live in the small intestine of the host, but unlike other parasites who consume the host's own food by absorbing it through their skin, hookworms attach to the intestinal wall with six sharp teeth, and feed on the host's blood. This is particularly detrimental to young puppies who can become anemic and die from a severe infestation.
The adult worms feed and mate inside the small intestines, and the resulting eggs pass into the world through feces. Once outside, the eggs undergo a transformation into infective larvae and make their way into a new host either by penetrating their skin, or more commonly by being ingested, usually through self grooming.
Once inside the body some of the worms become established in the small intestines, while other more adventurous ones begin a migration toward the lungs. In this process of migration they may become stuck in tissue where they form small cysts which from time to time release larvae back into the body. When the larvae are in tissue and not in the intestines, there are no eggs passed into the feces and the stool sample would be negative on testing.
The good news about hookworms is that unlike roundworms, their eggs are not resistant to freezing and they only last in the environment for a few months, up to a year. Also. it takes around 2-9 days from the time they exit the body in stool for the eggs to become infective larvae, so if stools are picked up and discarded daily that process can be avoided.
Prevention is key: clean your yard of stool daily and have your pet's stool checked twice a year. In addition some of the monthly heartworm medications interrupt the life cycle of hookworms, and so they aid in the reduction of parasite burden.