Common problems and illnesses

Before you start

This guide helps you recognise problems and know what to do first. It can't diagnose your horse. Many of these conditions start with vague signs, such as a horse that is dull, off its food or not quite right, so if in doubt, call your vet.

Colic has its own guide: Colic: the signs and what to do. Skin conditions such as mud fever, rain scald and sweet itch are in Skin and coat problems, and foot problems in Hoof problems.

Laminitis

Laminitis is a very painful condition of the laminae, the tissues that bond the pedal bone to the inside of the hoof wall. When they weaken and are damaged, the pedal bone can move inside the hoof. In severe cases it can rotate or sink through the sole, and the horse may have to be put down to end its suffering.

The British Horse Society stresses that there is no "safe season": laminitis can happen at any time of year, not just in spring.

Causes

• Hormonal. Up to 90% of cases are linked to hormonal disorders: PPID (Cushing's disease) and Equine Metabolic Syndrome. See Senior horse care.
• Excess weight, which the BHS says can more than double the risk.
• Inflammatory, for example from a big meal of concentrates overloading the gut, severe colic, or a retained placenta after foaling.
• Mechanical: overloading one leg because the opposite one is injured, fast or prolonged work on hard ground, or long toes and poor trimming or shoeing.

Signs

The early signs are often subtle. Look for reluctance to turn or to pick up the feet, a shortened or stiff stride, shifting weight from foot to foot, picking its way over hard or stony ground, heat in the hoof wall or coronet, a strong digital pulse, or a change in behaviour. The classic stance, rocking back onto the hind legs to take weight off the front feet, is seen in fewer than half of cases.

What to do

Call your vet immediately: laminitis should always be treated as an emergency. Don't force the horse to walk if it is reluctant. If it can walk, move it to a stable or shelter; if not, make it comfortable where it is and keep it off the grass. A stabled horse needs a deep bed, ideally shavings, to support its feet.

Once a horse has had laminitis, the damage is permanent and it is more likely to have it again. To lower the risk, keep your horse at a healthy weight (see Weight and fat scoring), check its feet daily for heat and a strong pulse, and keep up regular farrier visits: the BHS notes that leaving more than eight weeks between trims may contribute.

Choke

Choke is a blockage of the oesophagus, the tube from the mouth to the stomach. Unlike choking in people, the windpipe stays clear, so the horse can still breathe.

Causes include unsoaked or partly soaked feeds such as sugar beet, which swell in the gullet; bolting feed; dental problems that stop the horse chewing properly; whole fruit or vegetables; and foreign objects such as baling twine.

Signs: frothy discharge of saliva and food from both nostrils, repeated attempts to swallow, coughing or retching, stretching out the neck, spasms of the neck muscles, a bulge, usually on the left side of the neck, and an anxious horse.

What to do

• Don't panic: you need the horse calm, so the muscles of its neck can relax and the blockage can pass.
• Take away all food and water, including edible bedding, or move the horse somewhere it can't eat. Some horses keep eating, which makes the blockage worse.
• Call your vet if the blockage hasn't cleared within ten minutes and it's the first choke you know of, or straight away if you're worried. If your horse is prone to choke, agree a plan with your vet in advance.
• Don't try to flush it with a hosepipe or water bottle. That risks pushing material into the lungs and causing aspiration pneumonia.

After an episode, watch for a runny nose or faster breathing over the next few days: aspiration pneumonia can take a few days to show. To prevent choke, soak feeds properly, slice carrots and other succulents lengthways, use slow feeders for horses that bolt their food, keep up dental checks, and always provide fresh water.

Infectious diseases

These spread between horses, so the first steps are the same: isolate the horse and call your vet. The BHS and World Horse Welfare both point out that a raised temperature is often the first sign, so knowing your horse's normal temperature matters. See Preventative care for keeping disease off your yard.

Strangles

Strangles is caused by the bacterium Streptococcus equi, and is named for the way swollen lymph nodes can restrict the airway. British Equestrian describes it as endemic in UK horses.

• Signs: a raised temperature is often first ("hot before snot"), then thick, discoloured nasal discharge, swellings around the jaw that may burst, dullness, a low head, reluctance to eat or swallow, and a cough. Some horses show only a mild fever or slight loss of appetite.
• Spread: by direct contact, and indirectly through anything carrying discharge: water troughs, buckets, hay, tack, vehicles, and people's hands and clothes. It doesn't spread through the air. Signs usually appear 3–21 days after contact, occasionally up to 28.
• What to do: isolate straight away, without waiting for a diagnosis. Stop horses moving on or off the yard, take every horse's temperature twice a day, and tell anyone your horse has been in contact with in the last three weeks.
• Recovery: most horses recover in three to four weeks, but they can still spread the bacteria for around six weeks after the signs have gone. About one in ten becomes a long-term carrier. Only testing at the end of an outbreak shows when a horse is safe to leave isolation.

A strangles vaccine is available. See Vaccinations.

Equine influenza

Flu is a highly contagious, airborne virus that can spread over long distances. Signs appear one to five days after infection: a temperature above 38.5°C, a frequent harsh, dry cough, a watery nasal discharge that may thicken, loss of appetite, lethargy and swollen glands around the jaw. There is no direct treatment: rest, supportive care and a dust-free environment. Recovery can take several weeks, and the BHS advises asking your vet before returning a horse to work. Vaccination is the main defence; see Vaccinations.

Equine herpes virus (EHV)

EHV-1 and EHV-4 cause flu-like respiratory disease, especially in young horses, and can cause pregnant mares to abort. EHV-1 can also, rarely, cause neurological disease: weakness, poor coordination (usually worse behind), being unable to pass urine or droppings, and in severe cases being unable to stand. Once infected, a horse can carry the virus silently and shed it again when stressed, for example by travel or a move. Isolate and call your vet at once if you suspect it.

Gastric ulcers

Equine gastric ulcer syndrome affects as many as one in three horses, the BHS says. A horse's stomach makes acid all day, because horses evolved to eat little and often for up to 18 hours a day.

• Risk factors: long gaps without forage, high-concentrate diets with little forage, stress (hard exercise, travel, little contact with other horses or restricted turnout), and long courses of anti-inflammatory drugs such as bute.
• Signs: weight loss, dullness, poorer performance, resisting the rider's aids, grumpiness when girthed, rugged or groomed, colic-like signs, a poor appetite, teeth grinding, and crib biting. Some horses show nothing at all.
• Diagnosis: only a gastroscopy, a camera passed into the stomach by your vet.
• Prevention: plenty of turnout on good grazing, forage available through stabled periods, concentrates split into small meals, some forage or chaff about 30 minutes before exercise, less stress, fresh water, and diet changes made gradually over at least 10–14 days. See Forage first.

Equine asthma

Equine asthma is inflammation of the airways caused by breathing in dust, mould, bacteria, mites, pollen or ammonia. The BHS says severe equine asthma affects 14% of UK horses. Signs include coughing, nasal discharge, tiring easily, poorer performance and, in severe cases, laboured breathing at rest, with flared nostrils and a more obvious "heave line".

Your vet may prescribe medication, but reducing dust is the foundation: more turnout, low-dust bedding, soaked or steamed hay fed from the ground, good ventilation, and taking the horse out while you muck out. See Life in the stable.

Seasonal poisonings and diseases

Atypical myopathy (sycamore poisoning)

Sycamore seeds, seedlings and leaves contain a substance, hypoglycin A, that the horse converts into a toxin that stops its muscles producing energy. Most cases happen in autumn, when seeds fall, and in spring, when the seedlings grow. Horses can deteriorate within 6–12 hours, and the BHS reports that 56–61% of cases die.

• Signs: muscle stiffness and trembling, sweating, a high heart rate, a low head, brown or dark red urine, weakness or difficulty standing, and laboured breathing. Get urgent veterinary help.
• Lowering the risk: clear seeds and leaves from pasture, remembering that seeds blow in from trees elsewhere. Mowing and spraying don't remove the toxin, so seedlings must be taken off the field. Give extra forage on sparse grazing, use hay feeders rather than feeding near sycamores, and limit grazing to under six hours a day where sycamores are close. Don't make hay from contaminated fields.

Equine grass sickness

Grass sickness paralyses the gut. Its cause isn't fully understood. It is most common between April and June, in horses aged 2–7, and Great Britain has more cases than any other country, with more nearer the east coast than the west, particularly in Scotland. Signs include drooling, colic with no gut sounds, green fluid from the nose, drooping eyelids, patchy sweating, muscle tremors, a tucked-up belly, weight loss and trouble swallowing. The outlook is poor: acute cases are usually put to sleep, though around half of chronic cases may survive with intensive nursing. There is no vaccine.

The BHS suggests avoiding fields where cases have happened, disturbing the soil as little as possible, avoiding sudden changes in diet, following a testing-led worm control plan, and giving extra forage such as hay.