Thanks go out to
Ivy and Tenille at Cottingham Farm
on Bainbridge Island for hosting our seminar on physical examination and laminitis, with a focus on its relationship to spring grass. We love the opportunity for small group interaction and the commitment of our great clients to learning more about how to best care for their critters. Dr. Crystal presented a slide show describing what we know about laminitis in the horse. As with many devastating diseases, this one is always better to prevent than to treat.
Laminitis means inflammation of the lamina, the bit of tissue that holds the hoof capsule and the coffin bone together. When you think about the tremendous forces applied to the lamina with normal weight bearing, it's clear that this structure is a magnificent design! Think of the lamina as akin to a zipper, with zillions of interdigitating tubules interlaced in a thin band between the hoof and the bone. This specialized tissue has a complex blood supply supporting it. The blood supply as well as the laminar tissue is vulnerable to both external (concussion or trauma) and internal (metabolic blood flow) changes. The precise mechanisms are complicated, but we do know some situations that can precipitate laminitis. We know that it may be caused by trauma, as with too much concussion on hard surfaces (road founder) and by weight bearing overload, as when one forelimb is badly injured forcing all weight onto the other front limb (support limb laminitis). We also know that it occurs following episodes of systemic illness (diarrhea, toxemia, high fever) and in response to metabolic changes from a high carbohydrate (sugar) diet as with a grain overload or from unrestricted grazing on spring pasture. We know that some animals are more susceptible to laminitis than others including ponies, overweight animals, or those with Cushing's disease.
When laminar tissue becomes inflamed (from any cause) it reacts along a continuum of tissue changes that, if not stopped, ultimately results in failure of the "zipper" and rotation of the bone away from the hoof capsule. Prevention is especially important with this disease because even mild laminitis will heal with some damage to structural integrity, resulting in increased susceptibility to future episodes. If you suspect your horse or pony may have laminitis, or if your critter broke into the feed room and cleaned out the grain bin, call your veterinarian immediately, early intervention is second only to prevention!
Laminitis can be a seasonal malady in our region. After a long winter the delights of fresh grass can be irresistible. Our cool, wet spring weather significantly impacts how the grass grows as well as its nutritive value and pasture management (or lack thereof) further exacerbates its influence on your horses metabolism. In a nutshell, it's important to know your horse, introduce pasture grazing slowly and with restrictions as needed. Susceptible animals may need grazing muzzles, very limited exposure or no pasture grazing at all to stay free of laminitis. Brian Stahl joined us at Cottingham sharing some of the information available through county extension services about pasture management. You can take advantage of
county extension resources
online or call them for a consultaton.
Conducting a Physical Evaluation
Question, when is discussing laminitis a perfect segue to learning how to conduct a physical evaluation of your horse? Answer, when we want to know what to look for as signs of laminitis. Do you know how to perform a PE (physical exam)? Learning to perform a PE is not difficult but it's easiest to do as a "hands on" exercise, perfect for our gathering at Cottingham. We are grateful to Apache the pony and his adept handler Sally for our teaching assist. Check out our
for guidelines on
conducting a PE
. Regarding laminitis specifically, there are a few key signs that should raise the red flag when you do a PE on your horse. The first is overall presentation, stand back and look at how your horse is standing. Not four-square? Laminitic animals often try to shift their weight off the painful limbs, since that's usually the front feet, they often look like they're leaning backwards while standing and/or walking. Check their digital pulses. If you learn to do this in all four feet of your normal horse, you'll note that the pulse is more pronounced than usual in the affected feet if your horse has active laminitis. (Keep in mind that an increased digital pulse may also occur with a foot abscess or bruise etc.) Generally a horse with laminitis will have a normal rectal temperature, but they may have increased heart and/or respiratory rates depending on their pain level. Other vital parameters are usually normal except in extenuating circumstances but you already know enough to call your veterinarian, well done!
Helping you be the best you can be at caring for your animals is always on our to do list. We are happy for the opportunity to share new insights in veterinary medicine as well as teach old standbys of good horsemanship such as physical evaluation, bandaging and husbandry. Give us a call if you'd like more information about hosting a workshop at your farm or stable.