How To Choose:
When facing a flea infestation, flea sprays are a necessary tool, but not applied directly to your cat. As a general rule, we would not recommend using flea sprays regularly to treat fleas. A preventative strategy would be better. Instead, we would recommend regularly treating your cats with proactive flea control such as flea spot-on treatments or oral treatment for fleas. Some areas are at a higher risk for fleas during certain times of the year. Talk to your vet about when and if oral treatment is suitable for your cat.
If a flea spray to treat an infestation is needed, we recommend an indoor premise spray versus spraying your cat.
Suppose you must use a flea spray for your cat, in the short-term. In that case, we recommend Frontline Spray Treatment for Pets as it is relatively safe for both you and your purring friend, it is fast-acting, killing fleas on contact, and will kill ticks with some extra effort. It lasts for about 30 days giving you time to find an alternative flea treatment for your cat.
As with all flea products, we advise a consultation with your veterinarian before using flea products.
Most of the products we reviewed state that fleas will die upon contact. Flea eggs, larvae, and pupae are killed or prevented from hatching by some products. And some products also kill ticks. Other products, such as those made from essential oils, mostly repel insects.
Efficacy is one of the essential factors to consider when purchasing a flea spray. Products containing (S)-methoprene and Pyriproxyfen are known as Insect Growth Regulators (IGRs) and help control flea populations by sterilizing eggs for up to 4 – 7 months after application. Virbac Knockout E.S. Spray, Zoecon Precor 2000 Plus Premise Spray, and Hartz UltraGuard Plus Flea & Tick Home Spray are all indoor broadcast sprays that last the full seven months. Spot treatments, such as Zodiac Carpet & Upholstery Flea & Tick Spray and Zodiac Carpet & Upholstery Aerosol Spray, also continue killing flea eggs and larvae for a full seven months. Virbac Knockout Treatment Spray lasts only four months.
Aside from the Frontline Spray Treatment for Pets, all other chemical solutions applied directly to your cat are not only too dangerous to consider, but their efficacy is much shorter (30 days to 3 months) than a broadcast premise spray.
Nearly all of the essential oil products only last between a few hours and a few days, making them wholly ineffective in the case of a flea infestation.
Safety & Ingredients:
In each of our reviews, we noted whether the product posed a hazard or was toxic to humans and cats. In our studies of products that you can apply directly to your cat, you’ll note that we’ve recommended DO NOT BUY on all but the Frontline Spray Treatment for Pets. We’ve based our decision primarily on the safety of the active ingredients.
Products Containing Tetrachlorvinphos:
Tetrachlorvinphos (TCVP) is the active ingredient used in the Hartz UltraGuard Plus Flea & Tick Spray for Cats. TCVP originated in 1966 as a crop treatment and was canceled as such in 1987. “Tetrachlorvinphos was revoked for use in the European Union as of 2003 under Directive 91/414/EEC (European Commission, 1991)” according to the NCBI. In 2009, the National Resources Defense Council (NRDC) contacted the EPA and subsequently filed suit against the EPA to remove all pet products containing Tetrachlorvinphos (TCVP) from the market. The EPA denied the request to take all products off the market (see EPA’s report). According to the EPA’s document, the overall study to evaluate human exposure to organophosphates won’t recur until 2022. In the meantime, the EPA conducted an abbreviated evaluation and combined those results with an NRDC submitted a study. Both studies concluded that human life is at risk when using products containing TCVP. Toddlers who frequently touch animals and then touch or put their fingers in their mouths are at an increased risk. Exposing children to TCVP at such a young age could negatively impact their neurological systems.
Finally, for those who care about their pets as members of the family, we have to wonder, what are the potential risks to cats who consistently self groom? A study completed by the International Agency for Research on Cancer found a significant risk of developing multiple cancer types when testing this chemical on mice. According to MedVet, “Common signs of toxicity from flea products containing organophosphates are diarrhea, vomiting, difficulty breathing, small pupils, muscle tremor, weakness or falling over, and drooling. Organophosphate toxicity can be rapidly fatal, depending on the ingredients and dose the pet is exposed to.” We cannot say with certainty that harm will come to you, your family, and your cats by using TCVP. However, given all the data we’ve gathered, we would recommend not purchasing the Hartz product.
Products Containing Pyrethrin Products:
The majority of flea sprays for application directly to cats contain Pyrethrins or members of the Pyrethrin family of chemicals. The risks of Pyrethrin poisoning to mammals overall is relatively low. According to a NCBI study, “Pyrethroids are 2250 times more toxic to insects than mammals because insects have increased sodium channel sensitivity, smaller body size, and lower body temperature.”
However, cats are more sensitive. According to an academic study in 2016, pyrethrins are “extremely toxic to cats.” Exposure to this active ingredient can cause “characteristic clinical signs such as seizures (80%), muscle fasciculations (9%), tremors (95%), hypersalivation (100%) etc.” “Cats may be exposed from cutaneous application of topical products, oral ingestion, and direct contact with topically treated dogs.” Because this product poses a significant health risk to your cats, we recommend a DO NOT BUY for all these products.
Products Containing Essential Oils:
Many flea sprays contain essential oils which are not regulated by the EPA or FDA. Products containing essential oils have not been proven to kill insects and are also very toxic to cats. Texas A&M University’s Veterinary Medicine and Biomedical Sciences classify all essential oils as toxic to pets. According to the ASPCA, “Cats are especially sensitive to essential oils, and effects such as gastrointestinal upset, central nervous system depression, and even liver damage could occur if ingested in significant quantities. Inhalation of the oils could lead to aspiration pneumonia. There are significant variations in toxicity among specific oils. Based on this, we would not recommend using essential oils in areas where your pets have access unless pets are supervised or the use of the oil is approved by your veterinarian.” The Pet Poison Hotline stated that “Essential oils can pose a toxic risk to household pets, especially to cats. They are rapidly absorbed both orally and across the skin, and are then metabolized in the liver. Cats lack an essential enzyme in their liver and as such have difficulty metabolizing and eliminating certain toxins like essential oils.”
All of the products we reviewed are available through various retailers and do not require a prescription. However, we still advise you to please consult a veterinarian before embarking on a flea control journey with your pet.