LAMINITIS
by Dr. Hiltrud Strasser

The same steep hoof form is also responsible for a deficiency of blood flow and chronic overload of the dorsal part of the laminae, which sets the stage for acute laminitis.

A 12-year study of more than 200 coffin bones from slaughtered horses shows that rarely does one find a coffin bone not deformed and damaged by improper hoof shape. The palmar processes of a healthy coffin bone form an opening parabolic shape, while in contracted hooves it shows an elliptic arch The length of a healthy coffin bone equals its width; the commonly deformed coffin bone is narrower than it is long.

The horse's weight, with each step, is equally distributed onto the laminae. (In a calculation, this results in about 8kg per sq cm of laminae, at a canter.) Horses live with this for 30-40 years even in rocky areas.

Studies of wild horses show the coffin bone of a natural foot parallel to the ground and the frog/ bulbs actually touching the ground.
Domestic horses, however, are largely forced to live with high heels, and no frog contact. A change in the distribution of pressure results; the steeper the coffin bone, the more weight moves to the tip of the coffin bone and the more the laminae there are overloaded. Soft ground is less harmful under these conditions than hard ground.

The overloading of the laminae can be borne for some time if there is optimal circulation and good horn quality (unshod hoof). If anything like a metabolic disorder occurs, such as an excess in protein, the overloaded area becomes inoamed. Horses show pain and shift their weight rearward, onto parts of the hoof where the laminae is still intact.

With wild horses, actue laminitis heals quickly, since the animal has to migrate with the herd, and circulation resolves the laminitis within a few days. The rearward shift also shortens the overlong heels.

Veterinary treatment, however, focuses mainly on the innammation, or the already occurred rotation of the coffin bone. However, seen from a pathophysiological point of view, inflammation is a functional measure for repair: through increased bloodflow, metabolism (the exchange of waste products for nutrients and oxygen) is intensified. Basically, an inflammation is a natural repair mechanism; it causes pain, but has a function, and suppressing it (as with anti-inflammatories) prevents this natural healing mechanism from working.

This suppression of inflammation is usually done through medication and/or wedge pads. Metabolism diminishes, and healing becomes slow if not impossible, since healing requires increased metabolism.

Also, the use of wedge pads or bar shoes only increases the problem, doubling the pressure put onto the damaged region. Cells in the already damaged area die off, while cells on the edges of the afflicted area remain inflamed, producing wound secretion instead of stabilizing horn. Acute laminitis, therefore, is a long time in the making.

The "sudden" appearance of laminitis is brought on either by additional overload or several possible poisonous ingredients; however, these are not the causes for the laminitis, rather the "straw that broke the camel's back".

Pollitt shows dramatially in his video that a steep hoof is insufficiently supplied with blood; this is especially severe when the horse moves little, because it means long persisting vasoconstriction without the short frequent opening by joint motion.

So far, 50 horses with acute laminits were healed exclusively by lowering the palmar processes (bringing the hoof, and as such the coffin bone, back into its original position through trimming), and optimizing blood flow through the foot with movement, not medication or shoeing, etc.

Removing the cause (overload of the coffin bone) took 2-8 weeks, depending on the stage of the disease at the beginning. After 3-5 months, as soon as 75% of the coffin bone was tightly connected with the laminae again, the horse was able to move pain-free.

Copyright Dr. vet. med. H. Strasser
Blaihofstr. 42/1, 72074 Tuebingen, Germany
Tel/Fax: (011) 49-7071-87572
Ed. & Canadian contact: Sabine Kells at email: textorder @ shaw.ca

©2006 by The Horse's Hoof. All rights reserved. No part of these publications may be reproduced by any means whatsoever without the written permission of the publisher and/or authors. The information contained within these articles is intended for educational purposes only, and not for diagnosing or medicinally prescribing in any way. Readers are cautioned to seek expert advice from a qualified health professional before pursuing any form of treatment on their animals. Opinions expressed herein are those of the authors and do not necessarily reflect those of the publisher.