Besides annoying the host animal, fleas and ticks can cause skin disorders and infections such as Lyme disease, a potentially crippling syndrome.
The cost of the treatment is still unknown, and researchers don't know if it might help prevent Lyme disease and other tick-borne illnesses in humans, Meinke said.
For now, the drug is in the early stages of development. A similar oral drug only targets fleas, not ticks.
Ultimately, the drug could offer an appealing alternative to the medicated drops that pets absorb into their bodies, Meinke said.
And Beaver added that the topical treatments aren't right for all pets. Heavy coats, for instance, make it difficult to apply drops directly on the skin, she said.
"We have to look at a lot of different ways that we can help animals," she said. "New products are always welcome."
On the other hand, she added, "we've come a long way in being able to help animals infected with fleas and ticks."
Learn more about flea and tick treatments from the Humane Society of the U.S.
SOURCES: Bonnie V. Beaver, DVM, professor, Texas A&M University, College Station; Peter Meinke, Ph.D., senior director in medicinal chemistry, Merck Research Laboratories, Rahway, N.J.; Journal of Medicinal Chemistry, online, May 15, 2009
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