Four things you should know about flea and tick topical solutions

By: Darlene Hanenburg
Certified Veterinary Technician at Pet Poison Helpline®

Flea and Tick MedicationWith spring’s arrival, pet owners are starting their monthly rituals for controlling fleas and ticks, which typically involve application of a topical solution, or “spot-on” product. At Pet Poison Helpline®, spring also brings an increase in calls about topical flea and tick spot-ons. Concerns range from reapplying a product too soon to what to do when a product has been mistakenly applied to the wrong pet.

Here are four things I think pet owners should know before purchasing and applying a flea and tick solution.

#1 Yes, you really must read the label before applying any product to your pet.

You’d be stunned how many callers tell us they applied a product to their dog — or more likely their cat — and then read the label. Better yet, read the label before purchasing the product and read it again just prior to applying the product. Our pets rely on us for protection, not just from parasites like fleas and ticks, but also from misuse of products intended to protect their health. The label tells us how to correctly and safely use the product — including whether it can be applied to dogs only, cats only or both dogs and cats — as well as specifying the age and size of pet for which it is intended. Who to call for help or more information is also often found on the product label or packaging.

Need another important reason to read a product’s label? Some flea and tick spot-ons can have similar brand names yet contain different active ingredients (e.g., Advantage® II, Advantage Multi® and K9 Advantix®), which can be confusing to pet owners. Since some ingredients may be extremely toxic to cats (e.g., permethrin) and rabbits (e.g., fipronil), it is vital to know which species the product can be safely used on. High permethrin concentrations (40+%) can be toxic cats, causing vomiting, incoordination, difficulty breathing, tremors and seizures that can be life-threatening if left untreated. Labels of these products now include an explicit warning against use on cats, but the warning often goes unnoticed or is ignored because owners are not aware of the potentially severe consequences if the product is used on cats. Fipronil (e.g., Frontline®, Frontline Plus and others), even at concentrations found in spot-on products, is potentially deadly to rabbits, causing appetite loss, lethargy and seizures.

#2 Even if you intend to purchase a flea and tick control product elsewhere, talk to your pet’s veterinarian first.

This is especially important when treating very young puppies and kittens, elderly or sick pets, those on other medications, and those pets that are pregnant or nursing. Your pet’s veterinarian knows your dog or cat better than anyone — other than you and your family. And if you’re shopping for a flea and tick product for your dog, be sure to tell your veterinarian if you have a cat at home!

#3 “All natural” or “organic” doesn’t mean a product is completely safe or without side effects.

Essential oils, including peppermint oil, citrus oils (e.g., limonene, linalool), cinnamon oil and lemon grass oil, can be found in some topical flea control products. Because these ingredients are derived from plants and touted as natural or organic alternatives to chemical insecticides, many pet owners assume they are very safe. However, both dogs and cats can have serious adverse reactions to some of these ingredients, even when the product is used according to label directions. Side effects can include skin irritation, agitation or lethargy, vomiting, tremors and seizures.

#4 When used according to label directions, the active ingredients in many flea and tick topical products are not absorbed into the bloodstream.

One common misconception pet owners have about topical solutions is that the active ingredients are absorbed rapidly through the skin into the bloodstream. That’s not necessarily the case, although it varies from product to product. A spot-on treatment study in dogs and cats found fipronil concentrated in the sebaceous (oil) glands of the skin, the superficial epithelial layer (outermost layer of skin) surrounding pets’ hairs and the exposed part of the hair shaft. In addition, topically applied imidacloprid (Advantage® II, K9 Advantix®) and dinotefuran (Vectra 3D®, Vectra for Cats and Kittens®) remains on the skin surface, concentrating in hair follicles and sebaceous glands and is not absorbed. In contrast, moxidectin in Advantage Multi® enters the bloodstream.

The bottom line: Flea and tick control products play an important role in protecting pet health from other parasites, such as tapeworms, and diseases, such as Lyme disease. These products are effective, fast and easy to use, and safe — when used according to label directions. Sure, mistakes and accidents happen when using these products. And when they do, give us a call at (800) 213-6680.