The fight against the horse’s worst enemy: the fly

Here in the UK, both biting flies and non-biting flies bother our horses. Some horses can react dramatically to flies, resulting in distress and behavioural issues; especially during the summer season when flies are at their worst.

Understanding these pests and how they live can help you limit your horse’s fly problem, whatever the weather!

The different types of flies

Biting flies:

• Horse flies – feed on blood and can bite humans, too!
• Midges – saliva from their bite can cause a skin allergy called ‘sweet itch’.
• Stable flies – are attracted to dirty bedding and droppings; they target a horse’s mucus membranes, sweat, and open wounds.
• Black flies – usually attack a horse’s ears and the underside of their body.

Non-biting flies:

• Bot flies – buzz around a horse and lay yellow eggs on their legs (which can cause a parasite problem if ingested!).
• House flies – irritate a horse’s face and nostrils, especially in late summer.
• Face flies – feed on tears and mucus, so can often be seen hovering around a horse’s eyes.

The majority of flies only emerge during the summer months (especially during heatwaves), including horse flies, bot flies, house flies, stable flies, and face flies. However, midges and black flies are active throughout spring, summer, and autumn months.

How to protect against horse flies

A brilliant way to keep horse flies at bay is to stable your horse during the day.

Horse flies are out during daytime hours because they like bright light. So, keeping your horse stabled during the day can be extremely effective in the fight against horse flies!

Please note: You’ll need to safely install a fan pointing into their stable if your horse is stabled during hot weather; the movement of air can also deter some flies.

If your horse has to stay in the field during the day, using strong fly sprays and a fly rug with sweet-itch friendly material should help them cope with horse flies.

Additionally, your horse should have unlimited access to a cool shelter (free from droppings!) while in the field, to allow them to escape the heat of the day.

Managing sweet itch from midges

Signs of sweet itch in horses:

• Scratching their skin until it’s sore and inflamed.
• Aggressively biting their skin.
• Hair loss and lumpy or scaly skin.
• Loss of mane due to near-constant scratching on stable door frames, fences, trees, etc.
• Damage to the top of their tail from scratching it against stable walls.
• Restlessness or distress when midges are around.

Sweet itch cases often require a vet visit to work out the best defence against midge attacks. A vet might prescribe anti-inflammatory medicine if your horse is suffering from severe sweet itch, for example.

Here are some super suggestions for helping your horse cope with sweet itch:

• Use fly sprays and fly repelling creams, gels, or lotions that are suitable for sensitive skin.
• Bathe your horse using soothing shampoo that contains built-in fly repellent.
• Choose fly masks offering protection to your horse’s eyes, ears, and nose.
• While your horse is stabled, consider safely setting up a fan outside their stable (where they can’t reach it!) that allows a constant flow of cool air – this will make midges struggle to settle on your horse.
• Select fly rugs specifically designed for horses with sweet itch.
• Keeping their skin covered at all times, even while stabled (if your horse doesn’t find this comfortable, e.g. in hot weather, you may need to speak to a vet to find an alternative to leaving their sweet itch rug on in the stable). 
• Grooming your horse every day to check their skin for signs of damage, in case it needs soothing or anti-inflammatory treatment.
• Use insecticidal (fly-destroying) sprays outside their stable, to deter flies from visiting. 
• Ask your vet about supplements that could support your horse’s immune system, ease itching, and improve their skin condition.

Battling bot flies & their eggs

Just like dealing with other types of flies, you can battle bot flies by using fly sprays and fly rugs. However, your secret weapon for battling bot flies is the bot knife!

A bot knife is a tool designed to gently scrape bot eggs off your horse’s legs, to prevent them from accidentally eating the eggs while scratching their legs.

Tactics for fighting flies

In the war against all other flies, there are steps you can take to minimise their impact on your horse’s happiness:

• Keep stables, fields, shelters, paddocks, pens, and arenas free from droppings – flies dine on droppings and will gather if droppings are left. 
• Build muck heaps away from stables and fields.
• Ensure your horse’s water supplies are changed every day, since flies love hanging around stagnant (old, still) water.
• Cover open wounds to prevent flies from spreading infections.

Please note: The use of fly paper is not recommended in stables and barns because it can cause wild birds to stick to it and become injured.

Equipment to protect against flies

Shield your horse from swarms of flies, by using:

Fly spray

Selecting the right fly spray for your horse is important, because some horses are sensitive to certain ingredients.

If your horse dislikes the smell, sensation, or sounds of fly spray, there’s a large selection of alternative products to choose from:

• Fly repellent gel.
• Fly repellent cream.
• Fly repellent lotion.
• Fly repellent wipes. 

All equine fly sprays and repellents are regulated in the UK, so they should have an approval number displayed on the packaging. The approval number (which will begin with ‘HSE’ or ‘UK’ followed by a series of numbers) will let you know whether a fly spray or fly repelling product is safe for use on horses.

Ingredients commonly found in fly sprays for horses:

• DEET – also known as ‘Di-ethyl-m-toluamide’, DEET is believed to mask your horse’s natural scent to repel flies; never use human DEET repellents on your horse, though!
• Citronella – due to a lack of scientific research into the effects of citronella as a fly repellent, it can’t be marketed as a fly repellent product; however, many fly sprays that are safe for horses do contain citronella.
• Eucalyptus citriodora oil – is a natural oil that has proven to be effective at repelling flies.

Remember: Homemade fly sprays and repellents can be effective, though they can also contain harmful ingredients. If you’d like to make your own fly spray or repellent, it’s worth speaking to your vet about safe ingredients first. Always ask your vet for advice if you aren’t sure which fly spray suits your horse’s situation best!

Fly masks

Whether you prefer fly masks or fly fringes, there’s an amazing amount of choice:

• Fly fringes for the browband of your bridle.
• Fly fringes for headcollars.
• Nose nets for bridles.
• Fly masks covering only your horse’s eyes.
• Fly masks for use with a bridle.
• Fly masks with fly fringe muzzles.
• Fly masks with ear protection.
• Fly masks with nose protection.
• Fly masks offering protection for your horse’s eyes, ears, and nose.

Plus, most fly masks act like sunglasses too, by providing UV protection for your horse’s eyes!

Fly rugs

Fly rugs are also known as ‘fly sheets’. Many different types of material are used to make fly rugs and fly sheets, though they should always be lightweight and breathable.

You can find a fly rug for every situation, for example:

• Sweet itch rugs – almost entirely cover your horse, aside from their legs, and often have a neck cover, belly cover, and extra-long tail cover.
• Standard neck fly sheets – cover your horse’s shoulders, back, and hind quarters.
• Combo fly rugs – are standard fly rugs with a neck cover; you can also get fly rugs with detachable neck covers.
• Waterproof fly rugs – designed for use during spring and summer, these rugs usually have a waterproof section along the top of their back and neck cover.
• Zebra fly rugs – it’s believed that zebra stripes confuse flies and prevent them from landing on your horse; most companies create the above fly sheet designs with the option of a zebra pattern!

Should you have any concerns about fighting flies for your horse, speak to a vet.