Other than diligent tick control, what prevention advice would you offer to large-animal owners, as well as pet owners?
Little: Modifying an animal's habitat to discourage tick populations can really support the efficacy of any tick-control product used
because it limits the number of ticks the animals are exposed to and, thus, the risk of infection. If an animal is often in
or around a wooded area in a region endemic for Lyme disease, the chances are greater the animal will be infected. If the
owner can limit the amount of time the animal is exposed to ticks, that's better. Maintaining pastures; limiting the incursion
of understory and brushy, wooded habitat; or keeping a dog in a manicured yard rather than letting it run free on several
wooded acres can really help decrease the numbers of ticks an animal encounters. For example, a weekly walk in the woods with
an owner present, so long as acaricides are used, may be OK. But if the owner lets the dog have unlimited access to five or
10 acres of wooded land all day every day, that could be problematic.
Are any acaricides more effective in preventing Lyme disease than others?
Little: Those products that offer persistent control, more comprehensive coverage, are better than any short-acting over-the-counter
products applied by the owner after a tick is found on an animal or after infestations have already established. The important
thing is to apply the persistent products routinely. Once ticks are present, it's too late. Like most of us, I would always
prefer to kill the ticks as soon as possible, preferably before they attach.
How did you get interested in parasitology and what do you like about the field?
Little: In my second year of veterinary school, I took a parasitology course, and I was really fascinated by the stories of parasites—the
way they move through multiple hosts to complete their life cycle and how they use other animals as their ecological niche.
But what keeps me excited about parasites and parasitology is that the field is constantly changing; there's always new information,
new discoveries to be made. Plus, it's an area of veterinary medicine that has very practical applications. The progress we
make in understanding parasites and vector-borne disease systems can effect change and have a real impact on the life and
health of animals and people.
Tell us about your research on Lyme disease.
Little: Our research group focuses on the natural history of ticks and tick-borne pathogens in North America with a goal of furthering
understanding of the factors that conspire to maintain a cycle of tick-borne pathogens in nature and that ultimately provide
the source of infection to people and dogs. In the last few years, we have focused largely on ehrlichiosis and borreliosis
because of the importance those diseases have for the health of people and dogs. We also work on hepatozoonosis, a devastating
disease in dogs in the southern United States with an expanding distribution. Our broad goals are to understand the interactions
between reservoir hosts and tick vectors important in the transmission cycles, to map where the infections are occurring and
to establish evidence-based methods of prevention.
What research are you working on?
Little: We have a variety of ongoing projects in ehrlichiosis, borreliosis and hepatozoonosis, all geared toward trying to better
understand the natural transmission cycles of pathogens in nature and from ticks to pets and people.
Donna Loyle is a freelance medical editor and writer in Philadelphia and the former primary editor of the North American Veterinary