There are several Environmental Protection Agency (EPA)- and FDA-approved products, such as pesticides (which kill ticks), tick repellents (which keep ticks away), and a Lyme vaccine for dogs—but there are pros and cons associated with each. (Consumer Reports has not tested these products.)
Pesticides. Pesticides (such as fipronil, pyrethroids, and amitraz) come in the form of medicated dusts, collars, sprays, shampoos, and other topical or oral treatments. They kill ticks either via direct contact with the animal’s fur or skin, or in the case of oral medications, via contact with your pet’s blood. “The tick is still going to bite,” says Bierbrier, and that bite could lead to a skin infection, “but [the tick] will be killed before it can transmit any of the disease-causing organisms.”
Several decades ago, Consumer Reports urged the FDA to remove DDVP, a pesticide found in some flea collars and no-pest strips, from the market entirely, says Consumer Reports’ senior scientist Michael Hansen, Ph.D. But you can still find it in many products. While it’s not an ingredient in many of the more popular tick medications for pets, such as Advantage II, Frontline Plus, K9 Advantix II, and Revolution, you should make sure to read labels carefully if you want to avoid it.
With some of these pesticides, Hansen warns, “there could be some transfer to kids who have a lot of contact with their pets.”
According to a 2012 statement from the American Academy of Pediatrics, the evidence of whether childhood exposures to low levels of pesticides can be harmful is still emerging, but some data suggest these exposures may be associated with cognitive and behavioral problems, as well as with pediatric cancers.
Repellents. Repellent products, such as those made with permethrin, are designed to discourage ticks from hopping onto your pet to begin with. But since they don’t actually kill any pests, they won’t do anything to reduce the number of ticks in and around your house.
Permethrin can be toxic, however, so while small quantities are considered safe for dogs, it should never be used on cats—it can be very harmful to them.
Vaccine. The Lyme vaccine for dogs appears to be safe, but experts aren’t yet sold on its effectiveness—and it's best when paired with a repellent or a pesticide, says Thomas Mather, Ph.D., of the University of Rhode Island.
Part of the problem is that many dogs, especially in high-tick areas, have already been exposed to Lyme—often without showing any symptoms—and data suggest that the vaccine works best on dogs who have not been exposed yet. Your dog should be tested for Lyme disease before receiving the vaccine.
Reactions to the shot can include hives, itchiness, and facial and injection site swelling. Vets typically only administer it to dogs in high-risk areas, or if their owners specifically ask for it.