Disclaimer: The following is only general information. If you believe that your horse has a problem please call your veterinarian as soon as possible.

This is a very common hoof problem that can go undetected for some time before it results in lameness. Unfortunately, by the time your horse is lame the thrush infection has probably moved from the outside to the inside of the hoof and has become a very serious problem.

Thrush is caused by either a fungal or bacterial infection that usually starts in the crevices and groove of the frog. If dirt and muck (urine and manure) remain trapped around the frog then bacteria and fungus will multiply causing the early, external stage of thrush.


Signs and Causes

If you clean out the crevices and grooves of the frog with a hoof pick and find a black, pasty substance that stinks your horse has thrush.

The main causes of thrush are to do with horse care as well as their environment.

Stables that are not thoroughly mucked out everyday

Yards that do not drain after rain and turn into mud puddles


Paddocks with wet, swampy sections

Not regularly picking out a horse’s hooves with a hoof pick and brushing out the crevices

Irregular farrier visits to trim the frog

Lack of movement by horses that are kept in a yards or stables

This last point is becoming more of an issue as a growing number of horses are kept in stables rather than paddocks. When you see horses cantering across a paddock, kicking up clods of earth, they are flexing their hooves and self-cleaning their own frogs and soles. When the crevices and grooves of the frog are clean and open to airflow, bacteria and fungus find it harder to multiply.

All horses are susceptible to thrush, however horses with an upright heal and deep crevices beside the frog seem to be at greater risk and require more attention on a daily basis.

Treantment and Prevention


Take action immediately any delay in treatment may lead to a more serious problem

Move the horse to dryer ground

Trim back all the affected frog with a hoof knife or nippers. NOTE. The frog is an essential part of the hoof structure so be careful when removing the dead parts. If the damage is extensive ask your farrier or vet to cut it away for you.


Brush off all the dirt and dead tissue with a hard bristle brush.

Disinfect the crevices and grooves around the frog with a diluted iodine or chlorine-based solution. NOTE. Don’t make it too strong, follow the directions or your vet’s advice and try not to get it on the horse’s skin – it could burn.

Repeat cleaning and disinfecting daily until it clears up

If your horse has thrush and is also lame, call your equine veterinarian straight away. If the internal structure of the hoof is involved the vet may require the hoof to be poulticed, daily soaking in an antibacterial bath, antibiotics as well as a tetanus injection. If the bulb of the heel is involved, the vet may recommend that your farrier fit a special bar shoe to stabilise the heel, to help healing and to minimise pain.


Regular turn out time in the paddock for stabled horses

Regular exercise and opportunity for movement

Regular farrier visits to trim the hoof and the frog (at least every six weeks)

Daily hoof cleaning and inspection for stabled or yarded horses

Regular hoof cleaning and inspection for paddock horses (at least weekly)

Take shoes off in winter or spelling times to allow hoof to flex naturally

Assess whether your horse can go without shoes permanently (depends on work, environment and hoof structure)

Exclude horses from swampy ground or drain it

Improve drainage in stable and yard areas

Don’t be too aggressive with the hoof pick, you may actually cause the problem

Don’t be too heavy handed with chemicals – more is not necessarily better


Remember to wash your hands thoroughly after you have cleaned out hooves or treated thrush. You do not know what organisms are present.


The above information is only general in nature. If you believe that your horse has a problem, please call your veterinarian as soon as possible.

Identifying and treating thrush

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