First Aid for Horses: An overview of 10 common conditions

Equine welfare is at the heart of what we do in the racing industry. In this article, Equine Medicine Specialist Laura Nath takes a closer look at some of the common injuries and illnesses that need to be managed from time to time to ensure the health and comfort of the horse.

1. Hoof abscess

A hoof abscess is an infection beneath the hard sole of the hoof. Anyone who has ever had a tooth infection can imagine how uncomfortable this would be for the horse. Infection in the hoof causes local swelling, heat and pain and is a common cause of lameness. It can occur following a bruise to sole. Nails of shifted shoes are common culprits as they can penetrate the sole and take bacteria with them.

Treatment is aimed at allowing the infection to drain, which relieves pressure and improves the comfort of the horse. This is achieved by a vet or farrier identifying the site of the infection and creating a hole for the infection to drain through. Sometimes a warm poultice on the sole of the hoof is needed to aid drainage. Most cases resolve quickly once drainage is established and can return to exercise within seven days.

2. Stone bruise

A stone bruise sometimes precedes a hoof abscess, but in most cases will resolve with a short period of rest. A stone bruise is a localised area of inflammation beneath the hard sole of the hoof. It is so called because the increase in pressure on the sole due to stepping on a stone can cause this bruising. The inflammation causes pain and lameness. The bruising can sometimes be seen on close inspection of the hoof. Modification of the horseshoe might be needed to relieve pressure and improve comfort. Most cases improve over a few days.

3. Overreach

Overreach injuries occur in the heels of the front legs. The injury is caused by the hoof of the back leg overreaching and striking the front leg whilst galloping. There is usually a small abrasion to the skin or heel of the front leg. This can cause lameness and might require a dressing and topical treatment to keep the area clean and prevent infection. These injuries usually resolve quickly and the horse can return to exercise within a few days.

4. Laminitis

Laminitis is a more serious and debilitating condition of the hoof. It is caused by inflammation of the attachments between the hoof wall and the sensitive structures which help to support the pedal bone. As such the condition is very painful and can occasionally result in movement of the pedal bone within the hoof capsule.

Usually both front hooves are affected but occasionally the back hooves can also be involved. It can be caused by very high insulin levels which might be seen after ingesting too much sugar in grain or rich grass. Another cause in racehorses is repetitive bruising of the sole of the hoof when exercising on hard ground. Mild cases can improve over 7-14 days, but more serious cases can take up to three months.

5. Colic

Colic is a term used to describe abdominal pain. These days the term is typically used to refer to babies or horses and in both cases they can’t tell us where it hurts. Horses with colic display symptoms of varying severity including loss of appetite, stretching out the legs, looking at or kicking at the abdomen, frequent urination, pawing, lying down and rolling.

In most cases the pain subsides over 6-24 hours and anti-inflammatories and/or sedatives are given for pain relief and comfort. Common causes include build-up of gas in the intestine, diarrhoea or dehydration. It is also sometimes seen in horses after swimming. Occasionally, twisting or movement of the intestines causes a complete blockage which requires surgery for correction.

6. Tying up

Tying up is a long-recognised condition that used to be referred to as “Monday morning disease” in the draught horses that pulled our trams and transported our goods throughout the city. These horses would have a day off on Sunday and remain stabled whilst receiving their normal rations of feed. On Monday morning these horses would be stiff and sore.

Sound familiar? We now know that this disease is characterised by injury to muscle cells. Complete rest following strenuous exercise and a diet high in sugar contributes to development of the condition. Young fillies are most commonly affected. Recent research suggests that some horses that have repeated episodes have a defect in the genes responsible for regulation of energy and calcium in the muscle cells.

The condition is confirmed with a blood test which shows high muscle enzymes. Most cases resolve with pain relief and supplementation with fluids and electrolytes. A change to the training program or feed is sometimes needed. Very occasionally the condition is severe and requires hospitalisation and treatment with intravenous fluids.

7. Shin soreness

The shin of the horse is the main long bone below the knee, also called the cannon bone or technically the third metacarpal bone. For us, this is the bone in the palm of the hand directly under our “tall man” finger.

Shin soreness is one of the most common afflictions in young racehorses. It is characterised by pain and sometimes swelling on the front of the shin bone. The front of this bone bears much of the concussive force on the leg as the horse gallops. To adapt to these concussive forces, the bone ‘models’ and becomes thicker and stronger, ultimately producing a stronger, healthier athlete.

Horses early in their careers are more commonly affected because their bones are in the process of adapting. The condition is managed with modification of the training program and pain relief. Modifications might include a reduction in galloping exercise to allow the bone time to adapt before resuming high intensity training, or a complete spell.

8. EIPH

EIPH refers to Exercise Induced Pulmonary Haemorrhage and this condition is also referred to as ‘bleeding’. This condition affects a significant proportion of racehorses to varying degrees. The condition is caused by breakage of the small capillaries in the lung which causes bleeding into the airway.

Although pulmonary haemorrhage has occasionally been described in human athletes, horses are particularly prone to the condition. Horses have enormous pressures generated in the pulmonary arteries and large volumes of air are taken into tiny air sacs. This is necessary to allow the intake of oxygen and exchange of carbon dioxide that these incredible athletes require to power their muscles. In the most severe cases of EIPH, there is a large volume of blood in the airway and bleeding is seen from the nostrils.

If bleeding from the nostrils occurs more than once on raceday, the horse is banned from future racing. This ban is in place to protect the welfare of horses and jockeys. Less severe bleeding is diagnosed with endoscopy: passage of a camera into the trachea (windpipe) approximately 40 minutes after exercise. On this examination, blood can be visualised in the trachea, confirming the diagnosis.

Another method, which can be performed at any time, is sampling the fluid in the airway. This procedure is called a bronchoalveolar lavage or “lungwash”. Red blood cells and associated white blood cells which clear the haemorrhage are observed on microscopic examination of the sampled fluid. This disease is challenging to manage and directed towards improving any obstruction to airflow in the upper or lower airway such as asthma and reducing pulmonary pressures when exercising, sometimes with the use of diuretics.

9. Respiratory illness – what does a ‘dirty scope’ mean?

As mentioned above, endoscopy of the airways is commonly performed in racehorses to diagnose respiratory conditions. The procedure is well tolerated by horses and can be performed in the racing stables in a matter of minutes, usually without the need for sedation. Respiratory illness might be suspected in horses with poor recoveries, increased respiratory or heart rates after exercise, coughing horses or horses with snotty noses.

A clean scope, particularly after exercise indicates the absence of lower airway disease. A dirty scope usually indicates lower airway inflammation, most often due to equine asthma, although sometimes bacterial or viral infections might also be implicated. A sample of fluid might be taken and examined microscopically to help differentiate between asthma and pulmonary infection. Horses are likely to be treated with anti-inflammatories and for asthma, treatment is similar to humans with horses often being given inhaled medications.

10. What does a ‘Bad blood’ test typically mean?

Many horses have regular blood tests to monitor their health and a blood test would also be required to investigate any sign of systemic illness such as a fever, loss of appetite, weight loss or coat changes. A ‘bad blood’ test usually is a sign of viral or bacterial infection. This is most common in the respiratory or gastrointestinal tract. Such blood changes would be a high or low white blood cell count, or elevations in other proteins which reflect inflammation such as fibrinogen.

A high or low overall protein level, or a low red blood cell count (anaemia) can also be signs of systemic illness. The most common white blood cell types are neutrophils and lymphocytes and a very high or low neutrophil count in particular could be a sign of illness. The kidney and liver function are also routinely evaluated in a blood test and occasionally abnormalities of these organs might be detected.

As previously mentioned, muscle enzymes can also be checked. Electrolytes are measured which can help to identify dehydration or excessive electrolyte losses due to illness. Following any blood abnormality, the horse will be rested until the cause of the abnormality can be identified and treated. In many mild cases, the abnormality will resolve over 3-5 days with a reduction in workload, following which, normal training can resume.