Fly season in the UK means misery for horses — from nuisance house flies to painful horsefly bites and midge-triggered sweet itch. But not all fly sprays are equal. We’ve compared DEET-based, citronella, and natural options to help you find the right protection for 2026.
Best Horse Fly Sprays Compared
| Product | Active Ingredient | Duration | For Sensitive Skin? | Price |
|---|---|---|---|---|
| NAF OFF DEET Power | 19.6% DEET | 6–8 hours | ⚠️ Patch test first | £14–£22 |
| Leovet Power Phaser | DEET + natural blend | Up to 7 hours | ⚠️ Strong scent | £16–£28 |
| Carr & Day Flygard Extra | 20% DEET | 6–8 hours | ⚠️ Patch test first | £15–£25 |
| Lincoln Classic Fly Repellent | DEET + PMD | Up to 12 hours | ⚠️ | £12–£20 |
| NAF OFF Citronella Spray | Citronella oil | 3–5 hours | ✅ Gentle | £8–£14 |
| Barrier Super Plus | Herbal/essential oils + avocado oil | 4–6 hours | ✅ Coat-conditioning | £10–£18 |
DEET vs Citronella vs Natural
| Type | How It Works | Effectiveness | Best For |
|---|---|---|---|
| DEET-based | Masks scent cues that attract biting insects | ★★★★★ (most effective, longest lasting) | Heavy fly areas, horsefly protection, long rides |
| Citronella-based | Natural essential oil repellent | ★★★ (moderate, needs reapplying) | Sensitive horses, light fly pressure, paddock use |
| Permethrin-based | Synthetic insecticide (kills on contact) | ★★★★★ (kills + repels) | Very heavy infestations (check UK legality) |
| Essential oil blends | Mixed plant-based repellents (neem, tea tree, lavender) | ★★★ (variable) | Horses with sensitive/reactive skin |
Our Top Pick: NAF OFF DEET Power
NAF OFF DEET Power is the UK’s best-selling fly spray for a reason. Its 19.6% DEET concentration provides reliable 6–8 hour protection against flies, midges, and horseflies. Well-suited for UK conditions where persistent biting insects are common from May through September. Always do a patch test on a small area first.
Best for Sensitive Horses: Barrier Super Plus
For horses with reactive skin or those who dislike strong chemical smells, Barrier Super Plus uses a blend of herbal oils, essential oils, and avocado oil that repels insects while conditioning the coat. Also helps calm existing midge bites. No DEET, no artificial chemicals.
Application Tips
- ✅ Apply to dry coat for best adhesion
- ✅ Focus on legs, belly, chest, and ears — where flies land most
- ✅ For the face, spray onto a cloth or sponge first, then wipe on
- ✅ Reapply after rain, heavy sweating, or swimming
- ✅ Store in a cool, dark place — heat degrades active ingredients
Frequently Asked Questions
What is the most effective horse fly spray UK?
DEET-based sprays like NAF OFF DEET Power and Carr & Day Flygard are the most effective for UK conditions, offering 6–8 hours of protection against biting insects.
Is DEET safe for horses?
Yes, when used as directed. Always patch test first, especially on grey, pinto, or thin-skinned horses. Avoid spraying directly on open wounds or irritated skin.
How often should I apply fly spray?
DEET-based sprays typically last 6–8 hours. Citronella and natural sprays may need reapplying every 3–5 hours. Always reapply after rain or heavy sweating.
What repels horseflies best?
DEET (15%+) is the most effective repellent against horseflies specifically. Citronella alone is less effective against these aggressive biters. Some owners combine DEET spray with fly rugs for maximum protection.