Laminitis has been recognized as a major problem in the horse world for centuries. It is a reasonably frequent cause of lameness in the less severely affected, as well as a genuine reason for humane euthanasia in the more severely affected. It has been reported to be responsible for close to half of all lameness problems on breeding farms, and the equine insurance industry recognizes it as one of the most common reasons for an insurance claim.
LAMINITIS: WHAT IS IT?
Laminitis is inflammation of the laminae of the foot. The laminae are tiny finger-like structures in the hoof that interlock to join the coffin bone to the hoof wall, effectively suspending the bones of the foot inside the hoof wall. Inflammation damages the laminae making them unable to hold the coffin bone in place. With the weight of the horse pushing the coffin bone toward the ground and the pull of the deep digital flexor tendon rotating the coffin bone, the coffin bone will sink and rotate within the hoof. This process is extremely painful to the horse and results in lameness.
WHAT ARE THE SYMPTOMS OF LAMINITIS?
The symptoms of laminitis are of pain and can range in severity from:
- No perceptible pain/lameness (sub-clinical laminitis), but evidence of laminar damage, e.g. hoof rings and/or stretched white line is found in the feet
- To mild clinical laminitis where the horse shows a slight shortening of stride, “feels his feet” on hard or stony ground, strong digital pulse, slightly increased heart and respiration rate, likely still eating
- To total refusal to move or pick up feet, lying down a lot, heart rate may be over 80 bpm, respiration rate may be over 60 breaths/min, sweating and muscles rock hard
WHAT ARE THE CAUSES OF LAMINITIS?
Laminitis is the result of many disease conditions. Risk factors for developing laminitis include: carbohydrate (sugar, starch, fructan) overload, colic, diarrhea, excessive concussion, retained placenta, drug reactions, systemic infection, injury, obesity, genetics and insulin resistance.
Controlling the risk factors and preventing laminitis is easier than the cure.
HOW IS LAMINITIS DIAGNOSED?
It’s not always simple to diagnose laminitis. Acute laminitis may be mistaken for colic or tying up. Lameness due to laminitis may be misdiagnosed as hock lameness, bruised sole and abscess. Generally, if in doubt, assume laminitis until proven otherwise.
FEEDING AND MANAGEMENT TIPS
Nutrition countermeasures to avoid laminitis include the following:
- The base diet should consist of forage rather than sugar and starch – feeds with a combined sugar and starch content of less than 10% should be fed to these horses
In summary, laminitis is a very unique problem as it has numerous causes. It is one of the most complex problems facing the equine industry. In the event that you as an owner experience this problem with your horse, get veterinary help quickly. It is important to remember that each laminitis case is different and thus these can be very difficult problems to manage without the guidance of your veterinarian and farrier.