Insects can be repelled in many ways. Mechanical hindrance is when fly paper or fly rug is used. Insects can be distracted by warmth and sweet traps, in order for them to leave the animals in peace. There are many good chemical insecticides and natural fly repellents on the market. Chemical synthetic insecticides are often neuro toxins, where their mode of action is based upon insects’ higher sensitivity to the toxin compared to mammals e.g permethrin. The animals ability to tolerate the synthetic chemical insecticides varies. A common side effect of insecticides is skin irritation. It is safer to use spray-able insecticides outdoors, in order to minimize the exposure of the animal and care giver to the toxins. Cats and dogs are self grooming, which sets an extra consideration on the insect protection products used. Synthetic chemical insecticides transfer easily to the body with grooming. Always verify that the product is suitable for pets as well. Manufacturers instructions on the use of the insecticides should be followed carefully.
There are also topical suspension products, which are specifically suitable for pets. The high dose required in use of these in horses, specifically in allergic horses, can create a problem. Unlike the pets, the horses are often 24/7 outside exposed to insects and thus the required repellent effect higher. The high dose can cause skin irritation.
Natural compounds, various essential oils, have long history in use as insect repellents. After the EU biocide directive came into force, the marketing of effective natural insect repellents is in practice forbidden. It is not forbidden to sell products containing these oils with insect repellant properties but it is forbidden to market these products insect repelling. The intended use defines whether the product is according to biocide regulation insect repellent or not. Natural compounds are often well tolerated. However, some animals can be allergic to some natural compounds. Insect repelling properties are shown in: lavender, citronella, pitch, neem, eucalyptus, clove, cedar, peppermint, cinnamon, catnip, tea tree, thyme, lemongrass, lemon, orange, basil, pine, pitch oil and many others. The odorous natural oils distract the insects (e.g. culicoides (non see ums), ticks, flies) ability to smell/sense the animals. The animals are hidden under the smell of natural oils. The problem with natural compounds is their short duration time, specifically when together with ethanol. The duration time is often only 30 – 60 minutes. Good natural repellant is long lasting smell “cocktail”, which hides the animal from insects.
None of the repellents have 100% efficacy. Thus the repellents can help to reduce the amount of insects but the insects cannot be totally demolished. There are plenty of various natural products (lotions, sprays, shampoos), which have repellent properties. The efficacy and duration of the repellent property varies in these products. The rule of thumb in self made products is that care giver should always be able and willing to use the same product him/herself. Anything one would not apply on own skin and hair, should one not apply on cats, dogs or horses.
Use repellents always on hair, not on skin in order to minimize the stress on skin.