Internal & External Parasites

Parasites are organisms that depend on the energy of a host to survive. Some parasites feed off of the substance of the host itself, draining blood and nutrients away for its own purposes. Other parasites absorb some of the food that the host itself eats. Parasites can spread disease and cause many health problems among pets and humans.

  1. External Parasites

    • External parasites are almost always blood feeders, drawing on the host's blood to survive. External parasites almost always feed for relatively short times, taking what they need and then moving on. Some stay with a single host for long periods of time, and some smaller external parasites attempt to live on a host permanently.

    Lice, Ticks and Others

    • Lice are one of the more annoying external parasites, because they do not move on, nesting instead in the hair of the host and laying eggs there. Ticks are also annoying, since they tend to stay with a host as long as possible and can spread very dangerous diseases, such as Lyme Disease. Other external parasites, such as fleas, try to stay with a host but can also migrate when necessary. Others, such as flies and gnats, move on quickly but can still spread disease.

    Internal Parasites

    • Internal parasites generally stay with their host longer than external parasites. The life cycle of the internal parasite requires that they spend at least some time in a host's body, before moving on or dying. Some internal parasites stay within a host for most of their lives. Many prefer a certain tissue to live in, such as the digestive system or the vascular system.

    Heartworms, Tapeworm And Other Internal Parasites

    • Heartworms are one of the many types of internal parasites that use external parasites to move between hosts, traveling via mosquitoes. They mature and live in the heart, where they can plug up arteries at adult size. Tapeworms are more common and can grow up to 1 to 2 feet long in the small intestine. They are passed by fleas. Hookworms and roundworms also travel in similar methods and can replicate quickly throughout the body.

    Prevention/Solution

    • Usually, the best way to prevent internal parasites is to prevent external parasites. Sprays can help ward away some pests, and for pets certain topical treatments will kill ticks and fleas over a long time. Good hygiene is the best method for avoiding contamination by either type of parasites. Keeping skin and hair clean is very important, and cleaning up any waste material will prevent many types of parasites from spreading.

    Treatments

    • External parasites can be difficult to treat because of their transient nature. Shearing and topical ointments are the most common treatments. Internal parasites are treated using chemical compounds, usually in pill form, that kill off the parasites without harming the host. The body then takes care of the dead organism on its own.