Monthly Pet Pill Could Kill Fleas, Ticks

By Randy Dotinga
HealthDay Reporter

THURSDAY, July 2 (HealthDay News) -- Controlling ticks and fleas is drudgery for countless pet owners. Now, researchers report they're closer to developing a monthly pill that would conveniently rid cats and dogs of these disease-carrying invaders.

Many pet owners control fleas and ticks by applying medicated drops to the skin of their dogs and cats, but the drops don't work for every animal. Also, the parasites may eventually develop immunity to current medications, said Texas veterinarian Dr. Bonnie V. Beaver. A pill would offer an alternative to existing treatments, she added.

"We expect over time that we'll have to have new kinds of products with different kinds of mechanisms of action in order to stay ahead of insects," said Beaver, a professor at Texas A&M University who is familiar with the results of a recently released study.

In the study, researchers with the Merck & Co. pharmaceutical company report that a drug called nodulisporic acid effectively and safely killed fleas and ticks in dogs and cats.

The findings were published in the May 15 online issue of the Journal of Medicinal Chemistry.

The drug could conceivably be administered as a pill or in a solution, making it easier than a pill to give to cats, said study lead author Peter Meinke, a scientist at Merck Research Laboratories in Rahway, N.J.

The treatment appears to be effective for a month, Meinke said. "That's a somewhat remarkable accomplishment. Imagine an instance where a doctor says to take an aspirin and it's effective for one month."

Like some other flea and tick treatments, the drug kills insects as they feed on pets. The poison works as they digest the animal's blood, but is harmless to mammals, Meinke said.

"It delivers a lethal dose through dinner," he said.

Other flea and tick treatments -- sprays and powders, among them -- expose insects to poison when they alight on a pet's body.

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."

More information

Learn more about flea and tick treatments from the Humane Society of the U.S.