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The Case of Squiggy and the Bad Laminitis
Imagine someone slowly pulling your fingernails off. Sounds painful, huh? Then, imagine you also had to walk and support your full weight on those fingers while the nails are being pulled off. Send a shiver down your spine? That is one of the ways I describe laminitis, or founder in layman’s terms, to horse owners. A horse’s foot is the equivalent to the last joint of your finger with the hoof wall acting similar to our nail. In very simplified terms, laminitis involves the disruption of the connective tissue holding the hoof wall (ie our nail) to the internal soft tissue structures (ie our finger tip). It is a very painful condition, as you can well imagine. It is difficult to treat, disheartening to manage and often results in the end of a horse’s riding career and possibly their life. Some horses are lucky, some are not. A recent case of laminitis has prompted me to write this article and hopefully, this horse is one of the lucky ones. To protect the involved parties, we’ll call this horse “Squiggy”. He is a four year old gelding.
The causes of laminitis are varied and not always well understood. The majority of cases are caused by diseases or conditions related to other organ systems such as the gastrointestinal, respiratory, reproductive or endocrine systems. Grain-overload, endotoxemia related to colic, complications with foaling, and pneumonia or other bacterial infections are very common histories for foundering horses. Horses with Equine Cushings or other similar disorders are also thought to be more likely to develop laminitis. Squiggy’s underlying condition was most likely some type of tick-borne disease (like Erhlicia) which caused a very high fever. Occasionally, it can be very hard to identify the underlying cause or it may not always be obvious at first.
Regardless of the cause, the signs are usually distinct. Horses are very reluctant to move and exhibit a “sawhorse” stance with the forelimbs placed in front of the body. All four feet can be affected, but typically it is the forelimbs that are most affected. There is increased heat and digital pulses in affected limbs and they are usually painful with applications of hoof testers (a metal instrument that uses manual pressure to locate pain within the hoof).
When I first saw Squiggy, he was stuck out in the pasture at nine o’clock at night and he would NOT walk back to his stall. His acute pain and discomfort were obvious even to a layperson. He would only take one or two agonizing steps forward with a lot of coaxing. Squiggy’s temperature was still very high at this time, but otherwise, he showed all the classic signs of founder. His digital pulses were high, his heart was racing, and he stood with his hind feet under him and his front feet out ahead. So how did we get him back to his stall? Well, first a team of family and friends took down the fence so he had a shorter walk back to the barn. Then, by the light of many flashlights, I performed a nerve block on Squiggy’s front feet. A nerve block involves injecting a Novocain-like product around one or more nerves to numb or “block” a region of the body. This is similar to what your dentist would do before drilling. Once the pain in his feet had been blocked, Squiggy felt comfortable enough to walk forward and we managed to get him inside.
There are a number of treatment strategies once the diagnosis of laminitis has been made. First, the underlying cause must be addressed and treated. With Squiggy, we had already started an antibiotic called doxycycline for the possible tick-borne infection. Treating laminitis can be broken down into two phases – acute and chronic. In the acute phase, the focus is keeping the horse comfortable and preventing any rotation or sinking of the P3 bone in the foot. I need to give you a brief anatomy lesson first to understand that part.
 The diagram to the left shows the internal structures of the hoof from a side view. The P2 and P3 bones are the equivalent of the last two bones in your finger. P3 (or coffin bone) concerns us the most in laminitis. This bone is connected to the hoof wall by a special type of tissue called laminae (red line around P3 in the diagram). Because of the disturbances occurring in the foot during laminitis, the laminae can become inflamed or damaged. When this happens, there is a potential for the connection between P3 and the hoof wall to fail. P3 could actually rotate or sink in relation to its normal position in the foot. Rotation occurs more frequently than sinking, but any movement is bad. In severe cases, P3 will actually penetrate the sole of the hoof. Most owners elect to euthanize if this occurs because of the horse’s pain and the grave prognosis. Any rotation or sinking at all can result in serious long-term consequences for a horse’s comfort and use. The object and hope of treating acute laminitis is to prevent any rotation or sinking.
This is accomplished in a variety of ways and many veterinarians have different methods of addressing acute laminitis. Because laminitis is caused by a variety of factors, it has historically been hard to accurately study which treatments work best. New theories are constantly bounced around, so there is no ONE way to treat laminitis. Most veterinarians start by aiming to decrease the inflammation in the hoof. Applying ice or placing the foot in ice water is one method that has been shown to help in the first 48-72 hours of laminitis. Acepromazine works well as both a vasodilator and a mild sedative to help calm the horse. The benefits of acepromazine have been debated, so not all veterinarians use this drug. Anti-inflammatory drugs such as phenylbutazone (or bute) are one of the mainstays of treating laminitis and most horses will be on this drug for several weeks to months. The next step is helping support the foot and minimize any mechanical stresses. The shoes are usually removed and supportive pads or foam are placed on the feet. Deeply-bedded stalls are also recommended for both added support of the sole and protection for the horse. Laminitic horses tend to lie down a lot to take the pressure off their feet, so a well-bedded stall is essential for preventing sores and rubs. Horses must also be on strict stall rest during treatment. We placed Squiggy on bute, acepromazine and Gastrogard (a stomach protectant). His stall was very heavily bedded with shavings (nearly a foot deep, it seemed) and we placed foam pads on all of his feet. Squiggy’s owners even had the carpenter create a half-stall door so he could look outside at his buddies!
The length of treatment depends on the severity of the founder. Radiographs (x-rays) are always recommended both during and after an episode to evaluate the stability of P3. The radiograph on the right shows rotation of P3. The line representing the hoof wall should be parallel with the line along the surface of P3. The tip of P3 is also very close to the bottom of the hoof sole. I would be very worried about P3 going through the sole in this horse and would expect the horse to be quite painful. With mild laminitis in which there is little or no rotation, the recovery time is typically 6-12 weeks without any complications. Some horses require longer recoveries or develop chronic laminitis which has more involved treatment regimens. Mechanical stabilization of the foot is a very involved topic, one that I do not have the space to go into here, but corrective shoeing, frequent trimming, special pads or shoes may all be needed with some cases. Chronic laminitis can be difficult to manage successfully with frequent flare-ups.
As I mentioned before, laminitis can be very disheartening to treat. No matter what you do or how you treat, some horses will do well and some will do very poorly. Euthanasia is not an infrequent outcome because of poor prognosis for both the horse and its future usefulness. We still do not completely understand what causes laminitis or the best way to treat it. We do know that early and aggressive treatment is very important. Laminitis is a complicated condition, but hopefully this article will help you understand it a little better. It is a very scary thing when your horse is diagnosed with laminitis. Squiggy is hopefully on the road to recovery, but he isn't out of the woods yet.
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