Horse Health
Horse Hoof Thrush in the UK
Published Last updated 4 min read
Quick answer
Thrush is a bacterial infection of the horse's frog that thrives in wet, dirty conditions — the giveaway is a foul smell and black discharge in the grooves beside the frog. Pick hooves out daily, keep bedding dry, and ask your farrier or vet to pare away diseased tissue if it persists.
Key takeaways
- **Thrush** is a bacterial infection of the horse's **frog** that thrives in wet, dirty conditions — the giveaway is a **foul smell and black discharge** in the grooves beside the frog.
- Pick hooves out **daily**, keep bedding dry, and ask your farrier or vet to pare away diseased tissue if it persists.
What is thrush?
Thrush is a common bacterial infection of the frog — the V-shaped, rubbery structure on the underside of the hoof — and the grooves (sulci) alongside and through its centre. The bacteria involved thrive in wet, dirty, low-oxygen environments, which is why thrush is so common in UK winters and on muddy yards.
It is not usually serious if caught early, but according to Horse & Hound it needs addressing: left untreated, the infection can eat deeper into the frog and heel, causing pain and eventually lameness.
Signs of thrush
| Sign | What you will notice |
|---|---|
| Smell | A foul, rotten odour when you pick the foot out — often the first clue |
| Discharge | Black or grey moist material in the frog sulci |
| Frog changes | Soft, crumbly, ragged or shrunken-looking frog |
| Sensitivity | Flinching when the frog or heel is pressed or picked |
| Severe cases | Soreness, shortened stride or lameness; bleeding from deep clefts |
Check all four feet — thrush is often worst in the hind feet but can affect any hoof.
What causes it?
- Wet, muddy turnout and standing in deep mud or soiled bedding
- Infrequent hoof picking — packed mud and droppings trap bacteria against the frog
- Deep central sulcus or contracted heels, which harbour infection
- Poor stable hygiene — damp, dirty, ammonia-heavy bedding
- Lack of movement — exercise helps the hoof self-clean and pumps blood through the foot
According to the British Horse Society, picking your horse's feet out daily reduces the risk of infections such as thrush — particularly important for older horses, whose reduced immunity makes infections harder to fight off.
Treating thrush
According to Horse & Hound's veterinary advice:
- Remove the underlying cause — move the horse to a clean, dry environment
- Clean the feet daily — pick out all packed material and scrub the frog and sulci
- Pare away dead tissue — a vet or farrier should trim away diseased frog until healthy tissue is reached; do not cut into the hoof yourself
- Apply a topical treatment — your farrier or vet can recommend an appropriate astringent or antimicrobial product for the severity of the case
- Keep everything dry — clean, dry bedding and dry standing while the frog regrows
Bandaging may be needed if trimming has been extensive. Deep infections that track into sensitive structures need veterinary treatment, not home remedies.
Stable hygiene and prevention
- Pick feet out daily — every horse, every day, whether stabled or turned out
- Muck out thoroughly and bed on plenty of good-quality, dry bedding
- Manage mud — hardstanding, mats or woodchip around gateways, feeders and water troughs; see our mud fever guide for managing wet-ground skin and hoof problems
- Regular farrier visits — balanced, correctly trimmed hooves shed mud and stay healthier; the BHS advises routine visits, typically every four to six weeks
- Daily exercise or turnout — movement helps hooves self-clean
When to call the vet or farrier
- Lameness or obvious pain when the frog is touched
- Bleeding or discharge from deep clefts
- No improvement after one to two weeks of diligent home care
- Thrush that keeps coming back — there may be a conformation or management cause to fix
Sources & further reading
Facts in this guide are rewritten in plain English from publicly available UK advice. We name the organisation where a specific point comes from their guidance. Links below go to the original pages — use them to read the source material directly.
PETHEALTH+ is independent. These organisations do not sponsor, approve, or partner with this website. Guidance checked against sources listed below (last updated 2026-07-18).
- Mud Fever in Horses UK
- Horse Health Basics in the UK
- Senior Horse Care in the UK
- Donkey Care in the UK
- Horse Choke in the UK: Emergency Guide
- Horse Colic in the UK
- Horse Coughing in the UK
- Horse Cushing's (PPID) in the UK
Also see symptoms, symptom checker, and poison guide.
Frequently Asked Questions
- What does thrush look and smell like in horses?
- Thrush produces a foul, unmistakable smell from the hoof, with black or grey discharge in the grooves (sulci) either side of and through the centre of the frog. The frog itself may look soft, crumbly or eaten away.
- What causes thrush in horses' hooves?
- Thrush is a bacterial infection that thrives in wet, dirty, low-oxygen conditions — muddy fields, damp dirty bedding, and hooves that are not picked out regularly. Deep frog clefts and poor hoof conformation make it easier to take hold.
- Can thrush make a horse lame?
- Mild thrush usually does not cause lameness, but if it is left untreated and eats deeper into the frog and heel, the horse can become sore and lame. Lameness, bleeding or heel-bulb tenderness means it is time to call the vet or farrier.
- How do you treat thrush in horses?
- According to Horse & Hound, the underlying cause must be removed: move the horse to a clean, dry environment, clean the feet daily, and have dead or damaged tissue pared away by a vet or farrier, followed by a topical treatment they recommend.
- How can I prevent thrush?
- Pick your horse's feet out daily, keep stables clean with plenty of good-quality dry bedding, provide dry standing areas in muddy paddocks, keep up regular farrier visits, and give your horse plenty of exercise to stimulate hoof health.