Vet Insight: Injuries in the Field

Connie Bowkett-Pritchard BVSc PGCert (VetMed) MRCVS graduated from the University of Liverpool. She then completed an internship in an East Midlands referral hospital alongside a post graduate certificate with the University of Nottingham. She works at Field Equine Vets, a busy equine practice in Worcestershire and is currently studying for a Certificate in Advanced Veterinary Practice, focusing on lameness

Injuries in the Field

Wounds, hoof penetration & fractures

Field injuries are unfortunately a common part of equine emergency practice. A study1 investigating equine traumatic injuries found that 62 percent of horses were injured in the field; interestingly, cob and pony breeds suffered a lower incidence of injury compared to other breeds and competition horses had a higher injury risk.

This article will discuss common field injuries, give advice on what to do while waiting for the vet to arrive and provide information regarding veterinary procedures that your horse may require.

Wounds

Wounds are commonly due to kicks from other horses but can result from tangling in fencing and hedgerows. Not all require veterinary intervention but ones that do include: • Full skin thickness wounds (which may need sutures) – wounds can just penetrate the skin or go deeper exposing muscle (which appears a dark pink colour) and bone • Wounds near to a joint or tendon sheath • Profuse haemorrhage – if a wound has punctured an artery, the bleeding will be pulsatile and appear bright red • Limb wounds where the horse is markedly lame

Puncture wounds should not be underestimated as they can penetrate much deeper than suspected. If you are unsure, it is best to discuss the injury with your vet and sending photos can be very useful. When calling the vet, useful information to provide includes the horse’s tetanus vaccination status, the location of the wound (be as specific as you can), if bone or muscle is visible, the amount of bleeding, whether the horse is lame and the degree of lameness.

While waiting for the vet, cleaning the wound is a useful step to take. This can be accomplished using tap water; a hosepipe is useful to provide enough pressure to remove any dirt. Application of creams and sprays is not recommended – this hinders examination of the wound and can delay wound healing. If the wound is bleeding profusely, applying pressure is important – this can be achieved with a cotton wool bandage. A severely lame horse should not be moved unless it is unsafe for the horse or handlers to remain in the present location.

On arrival, the vet will check the horse’s vaccination status – tetanus vaccination is essential. This involves two primary vaccinations four to six weeks apart, followed by a booster 12 months later; subsequently vaccinations are given every two years. If a horse is not vaccinated, the vet will administer tetanus antitoxin which provides short-term protection but does not act as a vaccine. Cleaning the wound is important for a thorough examination; this is usually achieved with sterile saline.

The vet may use a probe to determine the depth of the wound and which structures are affected. Ultrasound and X-ray may also be needed. With limb wounds, it is very important to ascertain whether the wound has penetrated a synovial structure which include joints and tendon sheaths. Synovial sepsis (infection) is a serious condition with

consequences for long-term soundness if left untreated. A vet may test for synovial penetration using synoviocentesis (sampling fluid from the nearest synovial structure) or injecting sterile saline into the structure of concern and observing for leakage of saline from the wound.

A full discussion on wound healing is beyond the scope of this article. Suturing the wound can provide an improved cosmetic outcome and decrease healing time. Whether the wound is sutured, depends on the amount of time since the wound occurred, the degree of contamination, presence of infection, skin tension and wound location. To manage any wound, bandaging and rest are normally required. Horses with synovial sepsis require referral to a hospital facility with general anaesthesia, keyhole surgery with lavage of the affected structure and prolonged antimicrobial therapy to provide the best possible outcome.

Hoof Penetration

Hoof penetration always requires veterinary attention; it is usually caused by the horse treading on a nail. Depending on the depth of the nail, the coffin joint, digital flexor tendon sheath and navicular bursa (all synovial structures) can be involved causing infection. The pedal bone and deep digital flexor tendon can also be affected. While waiting for the vet, the nail should only be removed if its head protrudes beyond the margin of the sole – if left the horse may push it deeper when bearing weight. If removed, it is important to mark the location, direction and depth of the nail compared to its entire length. If the nail head is below the solar margin, it should never be removed.

The location of the nail indicates which structures might be affected. The hoof can be split into four sections; the sole and the point, body and base of the frog. Penetration near the point and body of the frog is usually concerning.

Your vet will use X-rays to assess the position of the nail relative to important synovial structures. If the nail has been removed but the nail tract is still visible, a metal probe can be used. Sometimes, the case is less ‘clear cut’ and additional diagnostics such as synoviocentesis (see above) or an MRI scan are required to determine if the nail has penetrated a synovial structure.

These X-rays show a nail penetration in a concerning location, close to the navicular bone – damage to the deep digital flexor tendon and sepsis of the navicular bursa were suspected. This horse was extremely lucky; further tests revealed that no important anatomical structures had been damaged

If there is no synovial involvement, the wound can be managed by opening the tract (using a hoof knife) to facilitate drainage, iodine dressings and poulticing. Synovial infection is serious and requires surgical management.

Fractures

A fracture is a possible diagnosis in any horse with a sudden onset non-weight bearing lameness. They normally result from kick injuries but can occur with fast movement or turns on uneven ground. These horses should not be moved unless necessary. Horses with fractures may have also sustained a wound but this is not always the case.

Some fractures can be obvious, but others require further diagnostics, usually X-ray. In horses with fractures higher up the limb for example, the humerus, shoulder, femur and pelvis ultrasonography can be useful as the horse’s extensive muscle mass precludes x-ray examination.

Unfortunately, some fractures are catastrophic and necessitate immediate euthanasia as repair and healing is not possible. This depends on the size of the horse, the fracture location, whether the fracture is displaced, simple (the bone is in two pieces) or comminuted (the bone is in several pieces), open (the bone has penetrated the skin) or closed. Generally, the higher up the limb the fracture is, the worse the prognosis, although there are exceptions.

Horses with fractures that require repair will need to be transported to a surgical facility. Before this, the limb must be stabilised. This is achieved through splinting the leg. Materials used as splints can include broom handles, a fence post and PVC guttering material.

Ways to Minimise Field Injury

Although not entirely preventable, certain steps can be taken to reduce the chance of field injury. • Maintain consistent turnout groups as much as possible • Introduce new horses gradually • Monitor the herd closely when introducing new horses • Avoid overstocking pasture • Use of protective boots • Ensure all horses are vaccinated against tetanus in case of accident • Regularly check fields and maintain fencing – avoid wire fencing if possible!

Field Equine Vets

Unit 3 New House Farm, Belbroughton Road, Blakedown, Worcestershire, DY10 3JH. 01562 701334 info@fieldequinevets.co.uk

References: 1.Owen, K.R., Singer, E.R., Clegg, P.D., Ireland, J.L., Pinchbeck, G.L. Identification of risk factors for traumatic injury in the general horse population of north-west England, Midlands and north Wales. Equine Vet J. 2012; 44; 143-148.

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