The pest within requires special care

Published 5:22 pm Monday, January 16, 2012

By DR. FRED SELF / Veterinarian

In last week’s column, we discussed the flea and how it uses its lifecycle to best provide itself with a host.

We discussed that the flea’s lifecycle was a simple one. The adult flea lays an egg that hatches out as a larva, which in turn forms a pupa and finally develops into an adult. A lifecycle that is simple with only one host.

Other parasites have a more complex lifecycle and require two separate hosts in order to develop into an adult. An example of this is the tapeworm that commonly inhabits dogs and cats.

The most common tapeworm we see in our pets is the double pore tapeworm, Dipylidium caninum. This particular tapeworm relies on the flea as an intermediate host. It does not parasitize the flea. Instead, the flea is simply a means by which to infect the next dog or cat.

When an adult tapeworm reaches maturity, it releases segments of itself to be passed out of its host. The segments resemble moving rice and can be found on the pet or seen when the pet passes stool. Each segment contains many tapeworm eggs.

When the tapeworm segment reaches the environment, it dries out and breaks open. At this point, the eggs are released into the environment. Once they are free in the environment, the tapeworm eggs become food for flea larvae. However, flea larvae cannot digest the eggs. The eggs remain and continue to develop in the flea larvae until they develop into adult fleas.

When the adult flea infests a dog or cat it runs the risk of being eaten by accident as the pet grooms itself. In the pet’s digestive tract fleas are digested and the tapeworm is released. The developing tapeworm then attaches to the lining of the pet’s intestine. The tapeworm is now in its definitive or final host and grows until it is ready to release egg filled segments of itself into the environment to start the lifecycle over again.

By using this more complex lifecycle, the tapeworm can pass from one pet to the next with little energy requirement. If you see what looks like a piece of rice on your pet and it waves at you, contact your veterinarian. Not all dewormers will kill tapeworms. Getting the proper medication is vital.

Dr. Fred Self is a veterinarian with Shelbiana Animal Clinic in Columbiana, along with Dr. Charles Thornburg. You can reach him at 669-7717.