Acute and chronic laminitis is a frustrating and often disheartening condition to manage. Having had the opportunity to observe, treat and shoe laminitic horses for over thirty years, it gives one a unique prospective into this disease. The biggest challenge to the veterinarian and the farrier is to improve function in a foot that may have potential, substantial and possibly permanent structural changes. It should be remembered from the onset, that it is the extent of the lamellar pathology (damage) that will influence our ability to treat a given case not the treatment regimen that is used. If this were not a fact, we would not read on a weekly basis in equine journals or magazines about some horse that was lost to laminitis. Another problem we need to overcome is that treatment regimens for both acute and chronic laminitis generally remain empiric and are based on the past experience of the attending clinician / farrier. Each case of laminitis should be approached on an individual basis.

Acute Laminitis

When we approach a case of acute laminitis, we encounter two problems. Again we have no way of knowing the extent of the laminar damage present and if this damage will be permanent when the animal first shows signs of acute laminitis. The number of horses that have suffered a severe laminitic episode that we are able to treat successfully is small and the window for treatment once signs are observed is also relatively small. Secondly, we have no practical means to counteract the vertical load of the horse’s weight that is placed on its feet. In other words we have no method that allows us to take weight off the inflamed lamellae. Frog pressure has become ingrained in the veterinary and farrier literature as a method to support the weight of the horse. If we consider the anatomy of the bottom of the horses’ foot, the horny frog (which varies in thickness) and the digital cushion above it, both are readily compressible structures under pressure. When pressure is placed over the frog, it quickly deforms, compresses and the interface between the outer surface of the frog and distal phalanx (P3) is diminished. These structures are generally irreversibly damaged by frog pressure and the animal often feels more discomfort. Therefore, I do not recommend this practice. To counter the forces acting on the bottom of the foot, I have always favored using the entire solar surface of the foot and applying either thick styrofoam, one of the deformable impression materials or placing the horse in sand. We do not recommend applying shoes in the acute stage. Recently we have applied wooden blocks that have the ground surface at the toe, sides and heels cut on an angle to horses with acute laminitis and the results are encouraging. They can be applied in an atraumatic manner. They will be described later in the text.

Chronic Laminitis

Chronic laminitis means that the distal phalanx (P3) has displaced within the hoof capsule. The distal phalanx can rotate downwards at the toe, rotate to either side (laterally or medially) or it can totally descend (sink) within the hoof capsule. Rehabilitation of the horse with chronic laminitis will again depend on the amount of viable lamellae that remain. I am often asked when to shoe a chronic laminitic horse. The guidelines I use are that the horse is comfortable, on minimal medication and the foot is stabilized i.e. there has been no further radiographic changes for a given period of time. Trimming and shoeing are directed toward realignment of the distal phalanx within the hoof capsule such that the solar surface of the distal phalanx is aligned relative to the ground. The second goal is to produce an adequate sole depth. This is accomplished through trimming and shoeing using principles that facilitate breakover, decrease the stresses in the deep digital flexor tendon and redistribute the load on the foot. Our shoe of choice is usually some type of wide web aluminum shoe with heel elevation or rails and impression material applied to the solar surface of the foot. Recently this writer has been very successful using a wooden block cut in the shape of the foot with the ground surface cut on a angle of at least 45º (see picture). The foot is trimmed appropriately, impression material is formed for an interface, heel elevation is used if necessary and the shoe is applied atraumatically using screws and a composite. With this procedure, all the mechanics are placed in the block while preserving the hoof capsule.

Radiograph before wooden shoe

Wooden Shoe - Note the new hoof wall growth

6 weeks later with sole healed. Note heel elevation and breakover in shoe

A Final Thought

With severe laminitis cases, we are often unable to rehabilitate the horse to where it has an acceptable quality of life. The main reason being that there are insufficient soft tissue structures remaining within the hoof to achieve realignment. I think it is important from a humane perspective, to know when to discontinue treatment that has not been effective. Often we persevere with various treatments, put the horse through much unnecessary suffering only to achieve an unsatisfactory outcome.

Stephen E. O’Grady, DVM, MRCVS
Equine Podiatry
Northern Virginia Equine