What flea treatments should dogs avoid?

Dogs can also become exposed at toxic quantities through the ingestion or absorption of household insect sprays, foggers, and granules. If the product is labeled for cats, do not give it to your dog—or vice versa. Do not use part of a larger-sized dose or multiple smaller doses, as this may result in an overdose and increased chance of poisoning. Do not give expired medications or cut larger sizes into smaller pieces or give multiple smaller doses. To prevent accidental exposure, follow all directions on flea and tick preventives and insecticides very carefully. Ensure that your dog only receives his prescribed medication as flea and tick preventatives are dosed on body weight. Also, make sure that you do not give more than one drug at a time, as that can cause an accidental overdose and can possibly interact with other medications.

Dogs should avoid flea treatments that include powerful insecticides such as imidacloprid and fipronil. Imidacloprid and fipronil, for example, are powerful insecticides: one monthly flea treatment for a large dog contains enough imidacloprid to kill 25 million bees. Given the scale of environmental contamination it is causing, prophylactic use of flea treatments on family pets cannot continue. The UK government is drawing up plans for a total ban on imidacloprid in agriculture but not for pet treatments. Why do I need to apply chemicals to them if they don’t actually have fleas?! Rather than blanket use, we strongly encourage vets and owners to take a risk-based approach to prescribing or recommending these medicines, reflecting an animal’s exposure to parasites. Owners should speak with their vet about their animal’s needs and how to responsibly use and dispose of these medicines to minimise environmental contamination.

Dogs can react differently to various active ingredients, and some health conditions may increase the likelihood of adverse reactions. Permethrin and Pyrethrins: While often used in topical treatments and sprays for dogs, these ingredients can be toxic to cats. Isoxazoline Class (e.g., afoxolaner, sarolaner, fluralaner, lotilaner): These oral treatments are effective against fleas and ticks, but the FDA has issued warnings due to reports of neurologic side effects, such as seizures, tremors, and ataxia, especially in dogs with a history of such conditions. MDR-1 Gene Mutation Sensitivity: Certain breeds like Collies, Australian Shepherds, and Shetland Sheepdogs have a mutation affecting how they process medications. Pregnant or Lactating Dogs: Many oral preventatives are not approved for use in pregnant or nursing dogs. Fipronil: Found in products like Frontline, fipronil is generally safe but may cause skin irritation or hair loss at the application site. Essential Oils (e.g., geraniol, peppermint, thyme oil): Marketed as 'natural' alternatives, these can still cause allergic reactions or toxicity, especially if applied undiluted or ingested. Garlic and Brewer’s Yeast: While sometimes included in chewables as natural repellents, garlic can be toxic to dogs in large quantities. Never use dog flea treatments on cats and vice versa. Always follow the manufacturer's dosage and application instructions. Avoid using multiple flea treatments simultaneously unless explicitly advised by a vet.