Beat the Flies with NAF

Kate Hore RNutr(Animal) R.Anim.Technol. NAF Senior Nutritionist

Here comes summer, and with it the familiar cry of ‘Which fly spray do I use?’ Read our brief guide to know what is what when choosing fly repellents.

Did you know? All fly repellents come under legal regulations. They must be registered and display a HSE number. This registration ensures you are using active ingredients proven to be both safe and effective, therefore look for the HSE number on repellents to ensure the product you choose is legal.

DEET in Fly Sprays

DEET (Di-ethyl-m-toluamide) is probably the best known, and well researched ingredient for fly repellents, and the basis of NAF OFF DEET Power Performance products.  Believed to work by simply confusing insects ‘odour’ receptors as well as creating an unappealing landing environment for insects, due to the receptors on their feet.  Companies include ingredients at various ratios, it is important to understand these ratios and inclusion rates, with respect to both safety and efficacy. Generally, the higher the rate of DEET the more effective it will be. However, safe levels for use on horses, and in our environment, are capped, so avoid using DEET repellents designed for use on people, as these are likely to be too high for your horse.

Beat the flies with NAF: Deet Fly Repellent

DEET is the key active ingredient in the NAF Deet Power Fly repellent range.

Eucalyputus Citriodora Oil in Fly Sprays

Eucalyputus citriodora oil is a natural derived oil with proven insect repellency, and is the active ingredient in NAF OFF Extra Effect products. Much like DEET, Eucalyptus citriodora is thought to work by disrupting the insect’s odour receptors.

Beat the flies with NAF: NAF Off Extra Fly Repellent

NAF Off Extra Fly Spray and Fly Gel features Eucalyputus Citriodora Oil as a key ingredient.

Citronella Oil in Fly Sprays

Citronella oil is traditionally used as an insect repellent, however, it’s legal status has never been established in terms of efficacy and safety, and therefore it cannot legally be sold as a repellent. This has led to confusion over the years, that maybe it is banned entirely or banned for competition use, but that is not the case. Citronella is still perfectly legal to use, both generally and under rules – it simply can’t be referred to as a fly repellent.

Beat the flies with NAF: Citronella Products

Many riders choose to use NAF Citronella Products on their horses in summer

Essential Oils in Fly Spray

The same applies to a number of other traditional essential oils, which sometimes leads to riders experimenting with homemade repellents, however this is something we strongly advise against. Essential oils, in particular, can be very aggressive, causing severe reactions on some horses, dependent on both concentration rates and how they have been combined. Therefore, whether looking for a fly repellent, or an essential oil product for general care, it is best to trust the professionals and buy a commercial solution. However, we still advise a small 24hr patch test is carried out before general application of any new product, simply due to the unpredictable nature of allergies.


When you are next asked the question, “Have you got the fly spray?” whether you are going to a competition or simply riding at home, take into account what is in your fly spray and follow the advice on the packaging.

Top Tips for a Fly Free Zone

  • Use only registered fly repellents, and follow the instructions on the packaging.
  • Try swapping between active ingredients each day, as it’s known insects can effectively learn to ignore a repellent when only one is used.
  • Flies love hot, sweaty horses – choose NAF OFF Citronella Wash after riding, to keep them cool, clean and fresh for turnout.
  • Avoid fields with standing water like ponds, and for sensitive horses stable at peak times of the day, such as early evening.
Your Horse's Health: with NAF

Enjoyed this blog? We've created a fantastic informative blog series with NAF that covers a huge breadth of important topics relating to your horse's health. Find about more about the series here.