The Laminitic Horse Series: Part 2- How to Identify Laminitis

In last month’s issue, we learned the definition of laminitis as “inflammation of the lamina,” or layers of the horse’s hoof. This series, “The Laminitic Horse”, was written to help you become more familiar with laminitis and know when to call your vet for help.

Laminitis occurs in degrees ranging from barely noticeable to extreme. When a horse is laminitic, it is likely experiencing degrees of inflammation in tissue structures throughout its entire body, but most notably the structures of the hoof.  Laminitis can be caused from internal (systemic) factors, like diet, as well as external factors, like stress. These can be argued and in fact are often the primary focus of professional veterinary and farrier conferences and workshops. Regardless of opinion, every factor present in any case of suspected laminitis should be considered in order to arrive at a diagnosis and helpful treatment plan.

Founder occurs when the lamina (layers) have been inflamed for an extended period of time. This extended inflammation can cause the coffin bone to lose connection with the hoof wall. Left untreated and without correction, founder can sometimes result in the coffin bone “collapsing” within the hoof capsule and eventually protruding from the sole of the hoof. While rehabilitation can sometimes be successful, often times euthanasia becomes the most compassionate and practical option. Your veterinarian should always be your first call if you suspect the onset of laminitis in your equine companion, or you simply have questions or concerns regarding laminitis. Quick response and an accurate veterinary diagnosis at the onset of symptoms is a key factor in the success or failure of laminitis treatments.

DIET: Having a proper, balanced diet for your horse has become a key to having a sound horse. What is a proper diet for a horse, especially highly managed equine athletes, horses used for ranch work, and active pleasure or sport horses that are ridden routinely?   The key to remember, is that the horse’s digestive system is designed by nature primarily to process grass, hay (roughage)and similar forage. Most commercial equine feeds are heavy with grains and sugar; oats, corn, barley, molasses and similar. Grains are high in starch, (complex sugars)and many experts today argue that those starches are much higher than horses can safely digest without creating health issues. In the digestive process starch breaks down into complex sugars like maltose and glucose. While the topic of equine nutrition has enough information and controversy to fill a book on its own, it’s good to understand (and subsequently consider as a possible factor,) the ingredients in the feed you are feeding so that you can avoid any potential problems with laminitis down the road.  The high sugars in feed (and grass) have long been suspected of being responsible for causing inflammation in the body. Until proven otherwise, this is one of the theories that many hoof care providers and veterinarians are working with when trying to manage the effects of laminitis in the equine. The inflammation caused by an “overdose” of hard-to-digest complex sugars may be the primary cause of laminitis in equine. It’s been my experience that removing sugar from the diet of a horse diagnosed with laminitis has proven to be a life-saver in many cases. But, just as every horse is different, it is important to approach every case of suspected laminitis individually. Working with your knowledgeable veterinarian, providing them with honest answers and complete details and history on your horse’s lifestyle and eating habits can help you develop a plan of care if your horse begins to experience laminitic symptoms. Visit www.safergrass.org to learn more about providing a healthy forage-based diet for your horse.

STRESS:

Why mention stress? Stress in horses (and people) causes an increase in the hormone cortisol. Cortisol is secreted by the adrenal glands and is involved in the proper metabolism of glucose (a sugar), insulin release so blood sugars stay balanced, inflammatory response and immune function. Did I say “sugar?” There’s our culprit, once again but in a different form. As “prey animals,” the horse will also secrete higher levels of cortisol as a response if they are forced into a “fight or flight” survival situation, for instance being introduced to a new herd, being chased by dogs or people, even rough and thoughtless training methods can cause an increase in cortisol. Determining stress levels in your horse can be one of the most critical factors in understanding the cause of possible laminitis. Most importantly, removing or reducing stress factors from your horse’s environment, training routine, or routine care can contribute immensely to the long term health of your horse.  It has been my experience that many horse owners fail to take an honest and open-minded look at what may be stressful to the horse. Much of what can stress our horses often seems perfectly normal to us, for instance hauling to a show, routine veterinary work, injury, sometimes even standing in a stall can stress the horse who prefers to stand with her BFF under the tree in the corner of the pasture. Separating her from her trusted companion, for instance stalling her during bad weather can be super stressful when she might feel safer (and perhaps less stressed) standing next to her buddy in the pasture, getting rained on. For some horses, none of this may be stressful. For others, a simple trailer trip to a schooling show might trigger a stress reaction. Like people, each horse will respond differently to different “triggers.” Some will yawn and sleep for the whole event, some may pace and worry, sweat and vocalize in distress. The cortisol production in the latter group will be higher, and those types of personalities can be more susceptible to laminitis. While some of this, like veterinary needs, are unavoidable if we are to care for our horses properly, we can certainly work to limit the amount and type of stress our horses are subjected to by recognizing them and treating them each as individuals. In doing so, a major factor in the cause of equine laminitis and resulting chronic founder can be avoided.

Equine Metabolic Syndrome.

Equine Metabolic Syndrome (EMS) can be defined in three parts: obesity/fat pads, insulin-resistance (similar to Type 2 diabetes in humans) and constant lameness. EMS can be a genetic trait, but can also develop over time in a susceptible horse or donkey. Your horse can show signs of EMS if their diet is high in sugar.  Horses that have EMS generally have “fat deposits” covering the neck, (cresty neck) shoulders, back and rump and have puffy eye sockets. Some EMS horses can also appear bloated, have trouble breathing, exhibit excessive sweating and have a strong digital pulse. A digital pulse can be read by pressing down on the main artery that enters the hoof, and can be felt by holding your two forefingers against the backside of the horse’s pastern, just between the coronet band and the fetlock. A strong digital pulse indicates inflammation in the hooves and possibly other parts of the body. Horses that have EMS will have laminitic rings on their hooves as well. Laminitic rings occur when the laminae become inflamed and the attachment of the coffin bone to the hoof wall becomes compromised. When the lamina is inflamed, the coffin bone can be detached at that period in time and then reattached by new healthy hoof growth. This is what gives the hoof wall a rippled or wavy effect. If you see a horse with ripples in its hoof walls, this could be an early sign of EMS. A knowledgeable hoof care practioner or veterinarian may be able to estimate the severity of the laminitic episode by looking at the space between the ripples. The physical appearance of an EMS horse that has foundered is a unique stance where the horse has its front legs stretched far out in front of it to relieve the coffin bone from pressure. Horses that have been foundered for a long period of time tend to get tight muscles from this stance. There is a blood test available that can determine insulin-resistance in horses. Always consult your veterinarian about questions/concerns regarding your horse’s health. For more information on how blood sugars can be tested to determine equine health, here’s an excellent website: http://www.equinemedsurg.com/ then click on equine insulin resistance link.

PREVENTION:

You and your vet should work together to determine the quality of your equine health care program, feeding program, stress factors, training regimen and turnout time/pasture access. With this information, your vet might recommend blood work and radiographs if the horse is exhibiting lameness or sensitivity to a hoof-tester pressure test. Your vet may recommend more pasture time or less depending on the individual equine and the presenting issues. In short, many steps need to be taken together with your veterinarian, as soon as possible after noticing a change in your horse’s soundness, in order to determine the best course of action to take. The goal of laminitis treatment is to prevent further damage to the internal hoof structures as the disease progresses so the horse can remain sound for years to come. If left untreated or if treated incorrectly, the goal then becomes one of pain management and in advanced cases, quality of life.

Checking for and identifying internal and external factors that can be directly associated with laminitis is an important task that horse owners should be doing daily. Along with identifying factors that cause laminitis, horse owners need to know the next step when faced with a lameness issue. In next month’s issue, I will introduce you to a few laminitis cases and show you the lifesaving steps taken, together with the horse’s veterinarian and owner in order to minimize the damage from the inflammation.