Q: We’ve heard all kinds of conflicting information about the effectiveness and safety of flea and tick products. Can you clarify and tell us if there are any new products worth trying?
A: If we seem to return to this topic every few years, that’s because fleas and ticks are pretty much a year-round problem in the Mid-Atlantic. And as these parasites evolve to resist our efforts to combat them, new products are developed to do a better job. The balancing act, of course, is to kill the pests without hurting our pets — or us.
It’s important to note that fleas and ticks aren’t merely a nuisance — they also transmit a variety of potentially serious diseases to animals and humans. Fleas and ticks don’t seem to serve much purpose in the grand evolutionary scheme of Earth’s ecosystem other than distributing disease pathogens.
There are two basic product types to help us control these parasites — “spot-on” topical ointments applied externally on a pet’s skin and chewable tablets that work systemically. Most veterinarians have extensive experience with both and may have products they favor when making recommendations to clients.
To further complicate consumer choice, some products kill only adult pests, while others also kill eggs and larvae. Some work against fleas, ticks and even heartworms. Others are only effective controlling one species. A few claim a repellent effect on fleas and ticks. And there are several other factors to consider, including cost and ease of use.
Two new chewable tablets earned approval from the U.S. Food and Drug Administration last year — NexGard and Bravecto. NexGard is given monthly and protects dogs against ticks and fleas. Bravecto promises one dose will provide three months of protection against fleas and ticks. NexGard and Bravecto are in the same chemical family; both kill by causing uncontrolled activity in the nervous system of fleas and ticks.
Dr. Michael Dryden, a professor of veterinary parasitology at Kansas State University, calls these new products “game-changers” in the fight against fleas and ticks. Dryden told The New York Times that there are areas, particularly in the southeastern U.S., where flea populations are strong and some treatments may not be working as well as they were a decade ago.
While Dryden says flea products generally continue to work well in most places, consumers need to be well-informed on the best way to use them, and what results to expect. If a home is already flea-infested, says Dr. Dryden, it may take “weeks or months … for a flea infestation to be gone, and that has nothing to do with resistance.”
Flea and tick products, new and old, are not without controversy and risk. In 2010, the Environmental Protection Agency ordered manufacturers to put better instructions on packages after the number of adverse reactions in pets jumped considerably — often because pet owners applied large-dog doses of topical products to small dogs, or used dog products on cats. However, the EPA did not recall any products.
Any individual pet may have an adverse reaction to any type of flea or tick product. That’s why we stress the importance of asking your vet to recommend an appropriate product and then using it exactly according to directions. Chewable pills may give some pets an upset stomach or cause vomiting or diarrhea, so it’s a good idea to give them with food.
Some of these flea and tick control products should not be used on young or small animals. And dog products should never be used on cats — some can be lethal. Even though you can purchase some over-the-counter flea and tick control products online and in stores, consult your veterinarian before trying anything new. Your vet can help you beat fleas and ticks while keeping your pet safe.