What Is the Best Natural Flea Killer for Cats?

Natural flea killers are an increasingly popular option for owners who are looking for pet-friendly, environmentally safe methods of eliminating fleas from their cats. Fleas are widespread parasites that live off the blood of cats, people, dogs and other animals. The adaptable insect can also dwell in carpet, furniture and bedding that is frequented by an unsuspecting host. Cats with fleas often scratch or bite an infected body part repeatedly, which can lead to painful, inflamed or broken skin, hair loss and secondary infections. Fleas may also contain tapeworm eggs, which can spread to cats that ingest infected parasites while grooming. Although less common, cats with sensitivities to flea saliva can develop an irritating skin condition called feline miliary dermatitis.

Learning about natural flea killers can be an important step in the process of eliminating these pests safely from infested cats and homes. Here are some of the most common products and methods for natural flea control.

Comparing Natural Flea Killers

Most prescription flea control products contain synthetic insecticides, or adulticides. These powerful toxins destroy adult parasites on infected animals. Some advanced formulas also contain substances designed to eliminate flea larvae and eggs. Although these products may effectively destroy parasites, they can also cause adverse and potentially harmful reactions in cats with allergies or low tolerances to certain chemicals. Here are some natural methods of flea control that many holistic animal care experts consider generally effective and safe for use in cats.

Boric Acid

Considered one of the oldest methods of natural flea control, boric acid is a weak mineral acid with insecticide properties. It's available commercially as boric acid or as a main ingredient in the cleaning agent Borax. Many users recommend applying boric acid to clean and vacuumed carpet, and then allowing it to sit undisturbed overnight. Remaining traces of powder can then be vacuumed the next day. Boric acid can also be rubbed into infested furniture and other household items. It's thought to be most effective at eliminating flea larvae.


Pyrethrins, another long-standing method of flea control, are made from chrysanthemum flower extract. They are generally considered safe and well-tolerated in cats, although rare reports of toxicity have been reported. Pytrethrins work by disrupting the function of the adult flea's nervous system. They are also the model for the synthetic flea killing chemical permethrin. Pyrethrins are found in a variety of flea control sprays, powders and shampoos. Some popular brands containing pyrethrin include Bio Spot and Zodiac.

Flea Combs and Natural Shampoos

Keeping cats clean and groomed can be another safe, effective method for natural flea control. Flea combs are specially designed with fine teeth to pick up fleas and eggs from fur and skin. Most experts recommend using a comb for a few minutes daily, until a cat is flea free. Bathing an infected feline with gentle, non-toxic shampoo can also help control parasites. In many cases, fleas can be killed simply with soap and water. A growing number of holistic and pet-safe manufacturers offer soaps and shampoos designed to eliminate fleas, including Only Natural Pet, Fleabusters and Ark Naturals.