Overreach and tread injuries are common in the equine athlete, particularly during training and competition.
They can occur, however, in any situation where a horse’s foot and/or shoe strikes another leg — or even where he is struck into by another horse. It’s not uncommon for a horse to sustain a laceration while out hacking or when turned out in the field.
In many instances these are relatively minor, one-off injuries that heal with no long-term consequences.
Some horses, however, have certain limb conformation and action that makes them more likely to strike an adjacent lower limb.
Other factors that may increase the chance of injury occurring include the horse’s stage of training; working on soft, deep surfaces; foot conformation or imbalance; shoeing methods; fatigue during exercise; and alterations in gait that reflect pain arising from some part of the body.
If a horse frequently overreaches or treads on himself, it is important to liaise with your vet or farrier to see if any underlying problems can be addressed to prevent ongoing injuries. Use of protective devices may be warranted in some cases.
What can make these injuries so problematic is the fact that the horse’s lower legs have very little muscle coverage. Vital structures such as tendons, tendon sheaths and joints therefore have little protection other than the skin itself.
This means that any wound that penetrates the skin of the lower leg (including the pastern and heel bulb area) has the potential to be more serious than a wound occurring on another part of the body where additional tissue offers extra protection.
Furthermore, the size of the wound does not necessarily reflect the degree of seriousness. Some fresh, large skin flaps that can be sutured (stitched) may heal quickly, whereas a small puncture wound sustained over a joint or tendon sheath (the borders of which may be only millimetres from the skin surface) can be life-threatening.
First-aid facts
An overreach or tread injury will require immediate first aid.
If there is any bleeding from the wound, place a sterile wound dressing over the area followed by a thick layer of cotton wool before applying steady pressure over the site until bleeding stops.
A piece of clean, dry material, such as a handkerchief or a stock, can be used to stem blood flow in an emergency if nothing else is available.
If blood seeps through the material or is pumping out of the wound, seek veterinary assistance while maintaining constant pressure over the site.
Any horse who is also very lame should be examined by a vet as soon as possible.
If he cannot bear weight on the leg, do not move him — except to safety if he is in immediate danger — until he has been assessed by a vet.
In the case of small skin wounds with no bleeding or lameness, immediate first aid should consist of washing the area with clean water to remove any dirt and reduce the levels of bacteria at the site. Use bottled water or boiled water that has been allowed to cool.
Grazes and puncture wounds that do not go deeper than the skin generally heal well with minimal additional intervention, but call your vet for advice if the wound is gaping or if there is a large flap of skin.
As always, it is useful to have a suitably stocked first-aid kit when at competitions or out on longer rides.
Ongoing care
Once the site is clean, it’s time to assess the wound for possible further treatment.
Tetanus is a very real threat and does kill. No matter what size the wound is, check that your horse’s vaccination is up to date.
It is important to seek veterinary advice for any lower leg wound associated with severe or worsening lameness. Painkillers such as bute (phenylbutazone) should not be given without veterinary guidance, as this can mask signs of more serious problems such as joint and tendon sheath infections.
While superficial wounds that affect just the skin will heal, given time, this will depend on how much skin has been lost, if there is infection at the site and the amount of movement disrupting the wound.
Your vet may decide not to suture, particularly if the wound is contaminated with dirt and is likely to become infected. Stitching could seal any infection within the tissues of the leg, which will delay healing further and could cause additional problems.
Movement is a major problem in this part of the leg. Relatively small wounds can take a frustratingly long time to heal, because the constant movement delays the work of the delicate cells involved with the healing process. This can also make these wounds prone to developing granulation tissue (proud flesh), which will require ongoing care and may involve dressing and bandaging by your vet.
Long-term consequences will primarily depend on which structures in the leg have been damaged.
Do remember that infection of joints and tendon sheaths can be fatal if appropriate treatment is not undertaken promptly and infection cannot be controlled. In addition, severe trauma to tendons such as the deep digital flexor tendon may prevent a horse from continuing an athletic career.
Occasionally, coronary band injuries can cause hoof wall defects that require further treatment.
Prompt and appropriate attention at the time of injury will maximise chances of a full recovery.
Ref: Horse & Hound; 2 April 2015
