At VCA Central Kitsap Animal Hospital we advocate of year-round external and internal parasite prevention. External parasites (fleas and ticks) and internal parasites (roundworms, hookworms, whipworms, tapeworms, heartworm, etc) are a real issue and potential concern in many of our companion animals. Age, lifestyle and environment are predisposing factors to contracting these infections, however because no pet lives in a vacuum, potential exposure and subsequent infection is a possibility and should be prevented when possible and treated as needed.
Adult fleas and ticks are visible to the naked eye but can be missed by even the most astute pet owner. And because the majority of their life cycle occurs OFF the pet, they can be developing in the environment unbeknownst to most owners. Fleas and ticks can cause a host of problems in our pets depending upon the severity and duration of infection but most importantly, they can also be the source of potentially life threatening infections. Fleas carry a variety of diseases and parasites (for example, tapeworms), some of which transmissible to humans ("zoonotic"). Flea-borne or transmitted diseases include but are not limited to Bartonella (Cat Scratch Fever), Typhus, and Plague. Ticks also carry a variety of diseases that can be transmitted to their host, animal and human, through their feeding behavior. Anaplasmosis, Babesiosia, Ehrlichiosis, Lyme disease, Rickettsiosis, Rocky Mountain Spotted Fever, Tickborne Relapsing Fever, and Tularemia are all examples of tick-borne diseases found within the United States.
Internal parasites (heartworm and intestinal worms) cannot be diagnosed by looking at a pet. These parasites live within the pet’s body. Most adult intestinal parasites (for example, roundworms) live in our pet’s small intestines. An adult roundworm has the capability of producing 85,000 eggs per day. These eggs are microscopic and when passed out of our pet’s body in feces can remain in the environment for years, providing a source of re-infection if ingested. Hookworms are less hardy in the environment, but unlike roundworms, which require ingestion to be contracted, hookworms can also infect their hosts (dogs, cats and PEOPLE) by penetrating and migrating through their skin. To see adult worms in the stool with the naked eye is an uncommon and an unreliable way to diagnose these infections, as these parasites when fully mature cannot survive in the environment. Puppies and kittens will occasionally pass adult worms (visible to naked eye) but this is only due to their small body size and heavy infection. Adult animals can have essentially no symptoms of disease but still be infected. Microscopic evaluation of fecal material by a trained individual is needed for accurate diagnosis of intestinal parasites. Roundworms and hookworms found in our dogs and cats can be transmitted to humans and are a recognized and well documented zoonotic concern.
Heartworm infection, as the name implies, describes a worm that lives in the heart (dogs) and/or the large blood vessels leading from the lungs to the heart (cats). Heartworm infections have been reported in pets worldwide, with higher prevalence in warmer humid climates. In our state of Washington we are lucky to have had very few documented cases in comparison to the southern and eastern United States; however, these numbers are increasing. Increased disease prevalence is likely due to changing weather patterns and population movement (people and pets). Animals moving in from heartworm endemic areas provide a source for disease spread. Mosquitoes spread heartworm, picking up or injecting immature worms into an animal’s circulation as they feed. Animals with heartworm do not become ill usually until late in infection and may simply present in heart failure or die. Treatment is expensive and not without risks and only available to dogs. No treatment is available for cats at this time, therefore prevention is key.