What is laminitis?
Laminitis is a crippling and painful condition of the horse's foot. Affected horses are recognized based on lameness, stiffness, reluctance to move and prolonged recumbency. It usually affects more than one foot at a time. The laminitis disease process affects the connective tissues ("lamellae"), which attach and connect the inner lining of the hoof capsule to the coffin bone (the bone at the bottom of the horse's leg). Disease of this connective tissue is very painful and, in severe cases, may lead to disattachment and structural compromise.
What is "founder"?
The term "founder" is commonly used synonymously with laminitis. However, in the opinion of some veterinarians, the term "founder" should be reserved for those horses in which the attachment of the inner lining of the hoof capsule to the coffin bone, has actually broken down and caused the coffin bone to change its position within the hoof. The weight of the horse is important in this respect, as it contributes to the distraction process through the deep digital flexor tendon.
It is likely that laminitis may arise as a consequence of numerous different causative factors. Most current information pertaining to the cause of laminitis is based on the laminitis seen in conjunction with intestinal disorders. However, it should be noted that laminitis sometimes occurs in the absence of any intestinal problem and may, in those cases, have an entirely different mechanism.
Some of the well-recognized causes for laminitis are:
What to Watch For
The fore feet are much more commonly affected that the hind feet, and the most common clinical presentation includes signs of lameness and stiffness. You may notice the following:
Laminitis is usually diagnosed based on the symptoms. The physical examination may show marked prominence of the digital arterial pulses and further evidence of pain, such as elevated heart rate and elevated respiratory rate. If the disease has been present for a considerable period of time, your veterinarian may notice abnormal growth of the hoof capsule, dropped sole, and a widened white line zone.
The diagnosis of laminitis is usually established by the following criteria:
However, radiography is advocated because it is typically important to:
It is not usually necessary to anesthetize the affected hoof in order to make the diagnosis. Obviation of pain may result in severe damage (new or further separation of the coffin bone from the lining of the hoof wall) and exacerbation of lameness if the horse is exercised excessively. Although it is severe, the pain actually "helps" to prevent the affected horse from causing further damage to compromised lamellae.
The most common reason that laminitic horses fail to make a good recovery is because the horse is allowed to self-exercise too soon; it is common for affected horses to be "turned out" sooner than 6-8 weeks following initiation of treatment. These horses have often been stall-confined for several weeks (during treatment). Much too soon, they are turned out and (in light of their recent confinement) allowed to run around. Neither the owner nor the horse has any appreciation for the fact that the lamellar attachments have not completely healed. Although the horse perceives that his feet are okay, the weakened attachments can all too easily be re-damaged - leading to a major "flare-up" and worsening of the underlying disease process.
The specific treatment should be determined by the veterinarian who has examined the horse based on his findings and results of radiography of the affected feet.
Other than the pain relief and the antiinflammatory properties of non-steroidal anti-inflammatories, (bute, banamine, ketofen), no drug has been shown to affect the course of laminitis. Despite years of research, this disease continues to defy solutions, and that is likely due to the fact that it can either be too late by the time symptoms are present, or the underlying problem has not been fixed.
Most veterinarians would agree, that laminitis is one major cause of suffering in horses, and it is difficult to know when to give up. Certainly, if the horse does not respond to pain medication, is relatively immobile, doesn't eat, has side effects of pain medication, if there is serious rotation of the coffin bone, hoof wall destruction, or infection, euthanasia should be considered.
These horses are suffering with little hope of relief. Eventually they will go down, and not get up. Although euthanasia is an extremely difficult decision, the picture is perhaps clearer with laminitis that with other diseases. You might want to set-up criteria for "suffering" and "indications for euthanasia," which may sound a little morbid, but if you put it on paper, that means you've thought about it. Talk it over with your veterinarian. They will be impressed and glad to help you further.
The prognosis is unpredictable, and it may be (and should be recognized as such) grave in some severe cases. Few "recovered" (remissive) horses will be able to work at a high level of performance.