Mange in Horses: How to Spot, Treat and Prevent It

Mange in horses is a parasitic skin disease caused by microscopic mites, and it is the reason behind a surprising number of stamping feet and rubbed-out fetlocks on British yards through the winter. Most owners meet it under a different name. If you have been searching for advice on horse mites, feather mites or itchy heels, you are looking at the same problem: mange is simply the skin disease that mites cause once the horse reacts to them.

It is far less common in horses than in dogs, but chorioptic mange in particular is a genuine nuisance in feathered types, and it spreads through a yard quickly. This guide covers the signs to look for, the types of mite involved, how to tell mange apart from the skin conditions it mimics, and what treatment actually looks like in the UK, where the medicines picture is not what most online advice assumes.

What Is Mange in Horses?

Mange develops when parasitic mites, tiny relatives of ticks and spiders, colonise a horse’s skin. The damage is only partly mechanical. Most of the misery comes from a hypersensitivity reaction to mite saliva and droppings, which is why two horses carrying similar numbers of mites can look completely different: one is bald and raw, the other barely bothered.

That distinction matters for treatment, because it explains why a horse can still be itchy for a while after the mites themselves are dead. It also explains why some horses on a yard act as silent carriers, spreading mites without ever showing a symptom themselves.

Not all mites behave the same way. Sarcoptes mites burrow into the skin. Chorioptes mites, which cause the common leg form, live on the skin surface and feed on flakes of dead skin. Long, dense feather suits them perfectly, because it traps dirt and skin debris and shelters them from temperature extremes.

Left alone, mange spreads across the body and opens the door to secondary bacterial infection, weight loss and general debility. A horse that rubs an itchy leg raw on a fence post has turned a skin irritation into an open wound, and that is usually what finally gets the vet called.

What Are the Signs That a Horse Has Mites?

Behaviour gives you the diagnosis long before the skin does, and it is the single most useful thing to watch for.

Early signs owners often miss

• Stamping, particularly when the horse is standing still in the stable
• Chewing or nibbling at the lower legs, or rubbing one leg against the other
• Rubbing against fence posts, gateposts, water troughs and stable walls
• Restlessness or irritability when being groomed around the legs or mane
• Fine scurf in the feathering that looks like dry skin or mud dust

In a feathered horse none of the skin changes are visible at first. You have to part the feather and run your hand down the back of the pastern, feeling for small crusts and roughened skin. Owners of heavily feathered types often find the first sign is that the horse objects to having its legs handled.

Signs as mange progresses

• Small raised bumps that develop into crusts and scabs
• Hair loss, at first patchy, then in larger bald areas
• Scaly, thickened skin that in chronic cases forms folds or ridges
• Weeping or moist dermatitis around the fetlock
• Broken skin and secondary infection from self-trauma
• Loss of condition and poor appetite where the itching is severe and persistent

What do horse mites actually look like?

You will not see them. Mange mites are microscopic and cannot be identified with the naked eye, so anything visibly crawling in the coat is far more likely to be lice, which are just about visible as moving specks. This is the practical reason a diagnosis needs a vet and a microscope rather than a torch and a hopeful squint.

The Types of Mange and Mites That Affect Horses

Several different mites cause mange in horses, and each has a signature location on the body. Identifying which one you are dealing with is what determines the treatment plan.

Chorioptic Mange (Leg Mange, Heel Mites, Itchy Heels)

Caused by Chorioptes bovis, this is by far the most common form of mange in horses. It affects the lower limbs around the foot and fetlock, starting as an itchy dermatitis with small bumps, then progressing to hair loss, crusting and thickened skin. Chronic cases develop a moist dermatitis of the fetlock. Affected horses stamp and rub one foot against the opposite leg.

Two features are worth knowing. First, signs typically subside over the summer and return with cold weather, so a horse that seemed cured in July may be stamping again by November. Second, chorioptic mange is a recognised differential for greasy heel in draft breeds, which is exactly why it is so often mistaken for mud fever.

Feather Mites in Horses

Feather mites are not a separate species. The term is the yard name for chorioptic mites living in the feather of cobs, Shires and other heavily feathered types, and it is what most UK owners actually search for. Because the feather both hides the signs and shelters the mites, these cases are usually further advanced by the time they are spotted. We cover the management of feathered legs in more depth in our guide to feather mites in horses.

Sarcoptic Mange (Equine Scabies)

Caused by Sarcoptes scabiei var. equi, sarcoptic mange is rare in horses but the most severe form. The first sign is intense itching driven by hypersensitivity, with early lesions on the head, neck and shoulders. Small bumps and blisters crust over, and the skin thickens and forms folds. Notably, it tends to spare the lower limbs and the long-haired regions that chorioptic mange favours, which is a useful distinguishing feature. It is highly contagious to other animals and to people.

Psoroptic Mange (Mane Mange and Ear Mites)

Psoroptes mites prefer densely haired areas: under the forelock and mane, the base of the tail, under the chin, between the hind legs and in the armpits. Lesions begin as bumps and hair loss and develop into thick, crusted scabs. Psoroptes cuniculi can set up in the ear canal, causing irritation, ear infection and head shaking, and a horse that has suddenly become head shy or is rubbing its ears is worth checking. Our guide to ear mites in horses goes into the ear presentation in detail. Psoroptic mange is now rare in UK horses.

Demodectic Mange

Demodex equi and D. caballi live in hair follicles and oil glands, the former on the body and the latter on the eyelids and muzzle. Demodectic mange is rare and behaves differently from every other type: it does not itch. Instead it shows as patchy hair loss, scaling or small nodules on the face, neck, shoulders and forelimbs. Because it is associated with a suppressed immune system, it has been reported alongside equine Cushing’s disease and long-term corticosteroid treatment. A non-itchy, scaly bald patch in an older horse is a reason to investigate PPID rather than just treat the skin.

Harvest Mites and Straw Itch Mites

Harvest mites, also called chiggers or trombiculid mites, live on plants and small rodents. Their larvae feed opportunistically on horses in late summer and autumn, producing intensely itchy bumps and weals on the face, lips and lower legs. It is a seasonal problem tied to grazing rather than a yard-wide infestation.

Straw itch mites live in hay, straw and grain and reach the horse through bedding and forage. The pattern of the spots tells you how the horse is fed: bumps on the face and neck point to a hay rack, while bumps on the muzzle and legs suggest feeding from the ground. Changing the forage source usually resolves it.

Which Horses Are Most at Risk?

Any horse can get mange, but chorioptic mange is strongly biased towards particular types, and knowing that helps you target your checks.

• Heavily feathered draft and native breeds, including the Shire, Clydesdale, Friesian and cob types such as the Welsh Cob
• Horses living out or standing in wet, muddy conditions through a British winter
• Horses on yards with high turnover, shared grooming kit or shared rugs
• New arrivals that have not been through a quarantine period
• Older horses and those with PPID or another condition that suppresses immunity
• Any horse in contact with a known case, including apparently healthy ones

That last point is the one that catches yards out. Horses can carry chorioptic mites without showing signs, so treating only the obviously itchy horse and leaving its field companions untreated is the usual reason an infestation keeps coming back.

Mange or Something Else? Ruling Out the Look-Alikes

This is where most owners go wrong, and it is worth slowing down over. Several common conditions produce crusty, itchy lower legs, and treating the wrong one wastes weeks. The table below covers the usual suspects.

Mud fever is the one that causes the most trouble, because it and chorioptic mange occupy the same patch of leg on the same sort of horse in the same season, and they frequently occur together. Mites damage the skin, and that damaged skin is then an easy target for the bacteria behind pastern dermatitis. If you have treated a horse for mud fever repeatedly and it keeps returning, mites are a strong candidate for the underlying cause. For a broader overview of what else can affect the skin, see our guide to the most common horse skin diseases.

How Mange Is Diagnosed

Diagnosis begins with a physical examination and a good history. Your vet will want to know how the horse is housed and fed, how wet and muddy the ground is, whether the signs change with the seasons, whether any other horses on the yard are affected, and what has already been tried.

The main diagnostic tool is a skin scrape. The vet uses a blade moistened with mineral oil to collect skin cells and crust, which are examined under a microscope to identify the mite. Psoroptic mites are recovered from scrapes fairly readily. Sarcoptic mites are notoriously hard to find, and a negative scrape does not rule sarcoptic mange out. Where the picture strongly suggests mange but scrapes are repeatedly negative, a skin biopsy may be used to reach a diagnosis, or your vet may elect to treat on the strength of the clinical signs and the response.

It is worth asking for a diagnosis rather than accepting a trial treatment, because the differential list includes conditions with completely different treatments, and because the answer determines whether every horse on the yard needs treating too.

How to Treat Mange and Mites in Horses

Treatment has three parts that have to happen together: get the mites off the horse, get the treatment down to the skin where the mites are, and clear the mites out of the environment. Skip any one of the three and the problem returns.

The UK licensing position, and why most online advice does not apply

This is the single most important thing for a British owner to understand. World Horse Welfare states plainly that there are currently no veterinary products licensed in the UK to treat mites in horses.

Most of the advice you will find online is written for the United States, where hot lime sulphur dip is a labelled treatment for sarcoptic, psoroptic and chorioptic mites and is usually described as the standard approach. That is accurate in its own market and is what the MSD Veterinary Manual records, but it does not describe what your vet in the UK will reach for.

Instead, UK vets prescribe under the veterinary prescribing cascade, the legal route that allows a vet to use a medicine outside its licensed species or purpose when no licensed alternative exists. The Veterinary Medicines Directorate oversees that framework. The practical consequence for you is simple: mite treatment is a prescription conversation with your own vet, not something to assemble from a search result or a feed merchant’s shelf.

Clipping and washing the legs

For chorioptic mange, getting the treatment into contact with the skin is most of the battle. If the case is caught early it may be possible to avoid clipping, but once mites are established, removing the feather is usually necessary so that products can reach the skin rather than sitting on the hair. Our guide to clipping your horse covers technique, though legs are a job worth taking slowly.

1. Clip the feather from affected legs so the skin is accessible
2. Wash the legs thoroughly with an antiparasitic or crust-softening shampoo, which lifts the dead skin and scabs the mites feed on and shelter under
3. Allow the legs to dry properly, since leaving them damp invites mud fever on top of the mange
4. Apply whatever topical treatment your vet has prescribed, working it down to skin level
5. Repeat the process after about ten to fourteen days to catch mites that have hatched since the first treatment

That repeat is not optional. Treatments do not reliably kill eggs, so a single application leaves the next generation to hatch out and reinfest the horse.

Prescription treatments your vet may use

Because nothing is licensed for the job, the products used vary between practices and cases. World Horse Welfare notes that vets often recommend a topical antiparasitic such as fipronil, sold as Frontline and licensed for dogs and cats, or doramectin, sold as Dectomax and licensed for sheep and cattle, which has proved effective at reducing mite numbers over the whole horse. Where Dectomax is chosen it is typically given as two injections about three weeks apart initially, followed by further injections at intervals of three to six months as the vet directs.

Oral wormers in the macrocyclic lactone group, ivermectin and moxidectin, are also used off-label and are effective against chorioptic, psoroptic and sarcoptic mites, usually as a repeated course rather than a single dose. Where the itching is severe, a vet may add a short course of a glucocorticoid such as dexamethasone to break the itch and scratch cycle, and antibiotics if the skin has become infected. Demodectic mange is often left untreated and may resolve on its own once any underlying condition is addressed.

None of these should be attempted without veterinary direction. Doses and intervals differ from the licensed use on the packaging, some of these products are dangerous to other species, and the dosing of a 700kg Shire is not the dosing on a sheep label.

Treating the yard, not just the horse

Chorioptic mites survive off the horse for a period, so the environment is a reservoir. Cleaning it is as much a part of the treatment as anything you put on the legs.

• Strip and disinfect the stable at each stage of treatment, not just once at the start
• Reconsider the bedding. Straw and deep litter are difficult to decontaminate, and shavings or rubber matting are easier to keep clean. Our guide to choosing shavings is a useful starting point
• Clean and disinfect grooming kit, and stop sharing brushes between horses
• Wash rugs, boots, bandages and numnahs that have been in contact with affected legs
• Treat in-contact horses at the same time, including those showing no signs
• Isolate the affected horse where practical while treatment is under way

Recovery: How Long Does It Take?

With prompt treatment, most uncomplicated cases improve noticeably within two to three weeks, and the itching often settles before the coat has fully regrown. Bear in mind that hair regrowth on a clipped, thickened leg takes considerably longer than the mites take to die, so a leg that still looks bald is not necessarily a leg that still has mites.

Chronic chorioptic cases in heavily feathered horses are a different matter and can take several months and multiple treatment rounds to resolve. Where cases drag on, the reason is nearly always one of three things: the treatment never reached the skin through the feather, the repeat treatment was skipped, or the environment and in-contact horses were never dealt with.

How to Prevent Mange and Mites

Prevention is mostly ordinary good yard management, applied consistently.

• Quarantine new arrivals and check their legs, mane and tail base carefully before they join the herd
• Keep on top of leg hygiene through the winter, washing mud off and drying the legs properly afterwards
• Clip or thin heavy feather on horses with a history of mites, so problems are visible early
• Keep grooming kit horse-specific and clean it regularly
• Maintain a sensible parasite control programme with your vet, which our equine worming guide covers in full
• Manage the ground and drainage to reduce standing mud around gateways and troughs
• Keep the horse in good general health and condition, since horses with other conditions are more vulnerable
• Handle the legs regularly, so that a horse objecting to it becomes an early warning rather than a training problem

Mites are not the only external parasite worth watching for through the year. Our guide to preventing and treating ticks covers the other one most likely to turn up on a British yard.

Are Horse Mites Contagious to Humans?

Some types can affect people. Sarcoptic mange is the main concern: it is highly contagious and causes an intensely itchy rash in people handling an affected horse, although the mite does not establish a lasting population on human skin and the reaction usually settles once the horse is treated. Chorioptic mites and harvest mites can also cause temporary itchy bumps on the arms and hands.

When handling or treating a horse with suspected mange, wear gloves and long sleeves, wash your hands and forearms afterwards, and keep the yard clothes you wore separate. If you develop an itchy rash, tell your GP that you have been handling a horse with a diagnosed or suspected mite infestation, because it materially changes what they are looking at.

When to Call Your Vet

Call your vet if any of the following apply, rather than working through shop-bought products first.

• Persistent stamping, leg chewing or rubbing with no obvious cause
• Crusts, scurf or hair loss on the lower legs, mane or tail base
• Skin that has been rubbed raw, or any wound that looks infected
• Repeated mud fever that clears with treatment and then returns
• A non-itchy patch of hair loss or scaling, particularly in an older horse
• Sudden head shaking or ear rubbing
• More than one horse on the yard showing similar signs
• An itchy rash on yourself or anyone else handling the horse

The British Horse Society and World Horse Welfare both run free advice lines if you want a second opinion on whether something warrants a visit, but neither substitutes for a diagnosis. Mange is straightforward to treat when it is caught early and identified correctly, and stubborn when it is not.

Frequently Asked Questions

This article is general guidance and does not replace veterinary advice. Always consult your own vet about diagnosis and treatment for your horse. Medicines mentioned here are prescription-only and are used outside their licensed indications at a vet’s direction.