Safety Data on Topical Flea and Tick Products
Author: Pet Poison Helpline
Published: 2010/04/08 - Updated: 2025/10/18
Publication Type: Informative
Category Topic: Service and Therapy Animals - Academic Publications
Page Content: Synopsis - Introduction - Main - Insights, Updates
Synopsis: This information draws on extensive safety data compiled by Pet Poison Helpline, a 24/7 animal poison control service, and incorporates findings from the Environmental Protection Agency's comprehensive review of topical flea and tick products. The guidance proves particularly valuable because it cuts through common misconceptions by providing concrete incident rates—approximately 16 incidents per 100,000 applications, with fatal outcomes occurring in roughly one of 200,000 applications—demonstrating these products are generally safe when used as directed. For pet owners, including seniors and people with disabilities who may rely on service animals or therapy animals, this information matters greatly since it combines authoritative scientific analysis with practical, actionable safety recommendations. Rather than promoting fear about medication-related injuries, the report clarifies that severe reactions typically stem from misuse, such as applying dog products to cats or miscalculating doses, and emphasizes that proper application protects both pets and humans from serious diseases like Lyme disease - Disabled World (DW).
Introduction
With the start of flea and tick season approaching, pet owners are once again wondering about the safety of topical flea and tick products and many have contacted Pet Poison Helpline looking for answers. This comes on the heels of the Environmental Protection Agency (EPA) recently announcing results from their ongoing review of Spot-On products, so named because they are typically applied to the back of the neck or shoulders of dogs or cats to control fleas and ticks.
Main Content
Last year the EPA and Canada's Pest Management Regulatory Authority (PMRA) noticed an increase number of adverse events reported to manufacturers regarding the use of common over-the-counter and prescription flea and tick products. This prompted the agencies to ask manufacturers to provide information regarding adverse event reports they receive from owners. Pet Poison Helpline, a Minneapolis-based animal poison control call center which provides advice for consumers and veterinarians, has also been tracking such incidents and working with manufacturers to aid in the collection of complete and accurate information regarding such adverse effects, allowing for an informed assessment of their safe and effective use.
After compiling, reviewing and analyzing much of the data provided to the EPA, Pet Poison Helpline experts concurred with EPA's assessment that when used correctly, the incidence of severe and fatal effects resulting from the application of flea and tick products is extremely low as compared to the number of applications that pet owners apply each year. And, when serious events occur, it is most commonly a result of misuse. For example, when dog products are applied to cats or when owners misread, misuse or miscalculate the dose or product that is appropriate for their animal.
"Data can also portray a disproportionate view of the issue, since the majority of reported incidents represent minor or non life-threatening events," said Dr. Rick Kingston, president of regulatory and scientific affairs for SafetyCall International and Pet Poison Helpline. "Owners may think that serious adverse effects are common and expected, but fortunately, the data does not show that animals are being seriously injured when flea and tick products are being applied properly."
If Spot-On products are safe, what do pet owners need to know?
Treatment with a fast-acting topical flea and tick medication on a pet can cause itching or brief irritation at the application site, as the product does its job and kills pests. As the animal reacts to this irritation, it can begin to fidget and scratch. For a loving pet owner, the animal's discomfort can be worrisome, prompting concerns regarding the pet's safety.
In addition, for some flea and tick products, a small proportion of treated animals may also develop a side effect called paresthesia - a tingling sensation at the application site. Fortunately, in the majority of cases it is a mild and self-limiting effect, but it does account for a large number of the reported incidents, and small breed dogs are commonly involved. Still, the occurrence of any adverse effect for any treated animal with a Spot-On product remains low across the board.
Based on sales and distribution data individually presented to the EPA by various companies, the overall incident rate for flea and tick products was calculated to be approximately 16 incidents per 100,000 applications. Additionally, the overall incident rate for cases classified with either a major or fatal outcome was about one in 200,000 applications. These data demonstrate that Spot-On products are generally safe when used appropriately and according to the directions.
Advice for consumers
When applied properly to pets, flea and tick products can help protect both humans and animals from flea and ticks, but also prevent transmission of infectious diseases (like Lyme, Erlichia, etc.). Adverse reactions in dogs or cats resulting from misapplication can include skin effects such as irritation or redness; gastrointestinal problems such as vomiting or diarrhea; or more serious effects to the nervous system such as trembling, appearing depressed or seizures.
"The key to ensuring pets' safety when using flea and tick products is to be vigilant about following the instructions on the package," said Dr. Lynn Hovda, DVM, DACVIM, director of veterinary services for Pet Poison Helpline. "Knowing the exact size and weight of your pet and not assuming a product can be used for all types of animals is essential for using the correct medication and appropriate dose on your pet."
Dr. Hovda recommends the following tips to ensure correct use:
- Read and follow the directions on the product.
- Know the exact size and weight of your animal and use the correct dose amount. Don't guess.
- Use a product for the animal in which the product was intended, i.e., do not use a dog product on a cat.
- Consult a veterinarian before using flea and tick products on weak, aged, sick, pregnant or nursing pets.
- Always monitor your pets for signs of adverse reactions, especially when using products for the first time. When in doubt, consult a veterinarian, the manufacturer (most offer emergency medical information numbers on the label), or call the Pet Poison Helpline for treatment recommendations and general assistance.
Pet Poison Helpline
Pet Poison Helpline is a service available 24 hours, seven days a week for pet owners, veterinarians and veterinary technicians that require assistance treating a potentially poisoned pet. Staff can provide treatment advice for poisoning cases of all species, including dogs, cats, birds, small mammals, large animals and exotic species. Pet Poison Helpline is available in North America by calling 800-213-6680.
SafetyCall International
SafetyCall International operates a 24/7 adverse event call center. SafetyCall professionals are nationally-recognized experts in the collection and interpretation of spontaneously reported incident data reported directly to the manufacturer. By providing innovative, high-value services to industry and government, the professional staff of SafetyCall has been actively enhancing product safety for over 25 years. During this time, our staff has managed over 1.5 million product incident cases, positively impacting the safety of products worldwide.