Insect Repellents for Dogs, Cats and Horses

Insects can be repelled using multiple strategies, and effective protection usually relies on a combination of methods.

Mechanical Protection

Simple mechanical barriers, such as fly sheets, nets, or sticky fly traps and flyrugs, can help reduce insect exposure.

Using Scent and Attractants

Insects can also be distracted by scent or heat, which reduces the overall insect load on the animal. Natural oils such as lavender, citronella, neem, and eucalyptus can act as repellents against midges, ticks, and flies. It is important to note that essential oils evaporate quickly, and their effect is often short-lived (typically up to 60 minutes). Longer-lasting protection can be achieved by blending different oils into a safe “scent cocktail.” Ethanol accelerates evaporation.

Keep in mind that horseflies are also attracted by heat, so scents alone may only partially repel them for short periods. Dark-coated horses tend to be bitten more often. Providing shaded areas on pastures is recommended to help keep horses cool and reduce insect bites.

Chemical Insecticides

Synthetic insecticides, such as permethrin, are also available on the market and are primarily neurotoxins. Their effectiveness relies on the greater sensitivity of insects compared to mammals. However, these products can cause skin irritation in sensitive or allergic animals, such as horses prone to summer eczema. Spray formulations should ideally be applied outdoors to minimise exposure for both the animal and handler. Dogs and cats lick themselves, which can lead to chemical absorption, so always check product suitability and follow manufacturer instructions carefully. Observe any hazard chemical warning labels and understand potential risks to the animal.

Topical Solutions

Localised topical solutions are suitable for pets. Horses at pasture, however, are exposed to larger numbers of insects, meaning higher doses may be required, which increases the risk of skin irritation.

Natural Insect Repellents – History, Use and Limitations

The use of natural substances to repel insects has a long tradition. However, under the EU Biocidal Products Directive, marketing highly effective natural repellents is essentially prohibited. This does not prevent the sale of products containing natural oils with insect-repelling properties, but they cannot be marketed explicitly as insect repellents. The intended purpose of the product determines whether it falls under the directive.

Natural substances are generally well tolerated, though animals can be allergic to them. Common insect-repelling natural oils include lavender, citronella, tar, neem, eucalyptus, clove, cedar, peppermint, cinnamon, catnip, tea tree, thyme, lemongrass, lemon, orange, basil, pine, and many other essential oils.

These strongly scented oils can deter insects such as midges, ticks, and flies. Insects detect the carbon dioxide exhaled by the animal using their sense of smell, and the oil scent “hides” the animal effectively. A limitation of natural oils is their rapid evaporation; their scent usually lasts around 60 minutes, especially if mixed with ethanol, which accelerates volatilisation.

A longer-lasting natural repellent can be created by blending several oils into a “scent cocktail.” However, no repellent provides 100% protection. Natural repellents can significantly reduce insect bites and stings but will not eliminate insects entirely.

Many natural products, such as creams, sprays, and shampoos, contain insect-repelling agents, but their effectiveness and duration vary. Regular and correct use is key to effective protection and maintaining skin health.

Safety and Application

Apply repellents to the coat or fur, avoiding direct application to the skin. This reduces the risk of irritation and ensures safe use.

For homemade repellents, test first on your own skin: if your skin tolerates the product for an hour in sunlight without reaction, it is likely safe for your animal.