Management of equine wounds Part 1 – what horse owners need to know

Horses injure themselves often. Darling Downs Vets (Westbrook and Oakey) advise on first aid then prompt equine vet treatment to ensure optimum healing and cosmetic results.

Horses as a species are particularly prone to sustaining traumatic injuries, making wounds a common encounter for horse owners and horse vets.

A management strategy for horse wounds should involve providing an environment that facilitates the most efficient wound healing possible under the individual circumstances. The aim of wound healing is to restore the integrity of the skin and this occurs in a series of stages, where inflammation, cell migration, tissue deposition and skin contraction eventually fills a wound and then forms a protective epithelium. It is important to understand that skin itself cannot regenerate and every wound will heal with some degree of scar tissue.

The duration, severity and location of a wound will play a large part in determining what treatment your vet may recommend. Influences on wound healing include the initial first aid applied, cleaning and debridement of the injury, bandaging, suturing and topical medications.

Factors that negatively impact wound healing including infection, excessive movement of the wound, age of the horse, disease and nutrition status and the presence of multiple trauma sites. The aim of owners and vets should be to minimise these factors while enhancing those that are likely to be beneficial.

Steps when a horse is injured:

Assess the situation and the horse.

Always ensure the safety of yourself, or any other people as well as the horse. Check for lameness as non-weight bearing may indicate more serious injury such as bone fractures or the involvement of joints or tendon sheaths. Assess the degree of blood loss, and the demeanour of the animal. If it is panicked, shaking, sweating and obviously distressed seek help as soon as possible. Move the horse to a safe, dry and clean area if practicable.

Check any wounds carefully.

Large skin flaps are obvious but smaller puncture wounds over tendons or joints are often overlooked, but can be more serious. Look for sites of bleeding, and any muscle, tendon or bone exposure.

Seek veterinary help.

The equine surgeons at Darling Downs Vets advise that optimally wounds should be sutured within six hours of injury. After this time, the skin edges may be too dry or fragile to hold sutures well and bacteria contaminate the wound. Too much inflammation present in the wound can also make suturing difficult. However, even if you believe a wound is older than six hours (such as may occur in our referral patients from western Queensland or northern New South Wales) it is still best to have a vet assess and treat the horse. As well as specific treatment of the injury, the horse may require tetanus antitoxin or booster injections, anti-inflammatories, pain relief or antibiotics. With the ease of digital technology, it is common now for owners to take a picture of the wound to send to one of the vets at Darling Downs Vets, to help plan the initial visit and first aid advice.

First aid before the vet arrives.

First aid essentially comes down to cleaning and covering. Pressure can be applied to a bleeding wound using absorbent pads such as cotton sheeting, gauze pads, folded towelling or Gamgee style dressings, covered with a firm elastic or cotton bandage. It is preferable to avoid fluffy cotton wool on an open wound. Grossly contaminated wounds full of dirt, hair or gravel should be cleaned before covering. Irrigating the area with saline is ideal, however at this stage, hosing the area with tap water can be acceptable. Carefully dry the adjacent skin and then cover the wound with bandages while you are waiting for the vet to arrive, or while you are transporting your horse to our Westbrook clinic.

What agents are OK to use on wounds?

Try to avoid putting any type of topical medication (except for a bandage) on a wound until a vet has been able to assess it. When cleaning wounds, 0.9% saline solution is preferred if it is available, as it is isotonic (i.e. the same concentration as other body fluids). This is the ‘sterile saline’ that is found inhuman first aid kits, usually as small bottles for flushing eyes or wounds. The volumes required for horse wounds are much greater, so 500ml or 1L bags are preferable. Ask your vet for these to have on hand in your stable first aid kit. The top of the fluid bag can be cut off or a needle can be inserted through the rubber port, to enable sterile flushing of wounds (Fig 1).

Tap water can also be used for cleaning wounds, with some pros and cons. It is definitely preferable to use tap water for cleaning than to leave a wound badly contaminated or allow it to become excessively dry and hard. Excessive use of tap water may cause tissues to become swollen and more inflamed in the initial stages of wound healing and of course it is not sterile, so its use in wounds involving joint or tendon structures should be avoided. Other flushing solutions include iodine and chlorhexidine solutions. 1% povidone iodine solution is satisfactory for cleansing, but both of these agents will not kill bacteria at the concentrations used for wound flushing. Stronger iodine solutions and caustic substances such as hydrogen peroxide should not be used as they will damage healthy cells.

There are many topical wound medications available for use in horses and many owners will have their favourite products. In most situations, topical medications are not required for wounds that are sutured or those that are kept clean and bandaged, although there are some exceptions. Wound dressings such as honey or antibacterial ointments will not delay wound healing, so most vets are not opposed to their use. Substances that should never be put on a wound include petroleum products, Stockholm tar, radiator fluid, Dettol or any other caustic materials – basically if you wouldn’t put it on yourself, don’t put it on your horse.

Table 1 gives some suggestions for contents of a stable first aid kit. Darling Downs Vets and nurses are happy to supply horse owners with advice and first aid kit contents.