Many horses that seem to suddenly develop a full-blown laminitis attack may actually be battling a constant, low-grade, smoldering laminitis. They may not be head-bopping lame or move with that noticeable “walking on eggs” kind of gait, but they’re likely always compensating for pain to some degree. When too many factors get out of whack, they appear to experience yet another “acute” attack.
In reality, they’ve never actually been “cured,” and each day that goes by without a proper therapy reduces the chance of complete recovery. The first task, of course, is to get past the acute stage with the least amount of damage possible, as outlined in our April 2004 issue. Once this is accomplished, the war on chronic problems begins with a look to determine if the horse is actually constantly laminitic or not.
An astute farrier may have noticed an abnormally wide white line or periodic red or black discolorations in the white line that indicate laminitis. However, these changes usually are mentioned in a ���hindsight” kind of format, as the signs can point toward other, less-serious problems as well. And, if the horse isn’t in acute pain — as is often the case in chronically laminitic horses — no one’s really looking for a problem anyway.
That said, the combination of these changes, the history of periodic acute bouts of laminitis and other telltale symptoms may allow you to zero in on the cause of your horse’s distress and turn him around.
Many chronic laminitis horses will tend to:
• Move around less, especially when it comes to trotting or cantering on their own.
• Spend more time lying down.
• Stand with the feet either farther front or back than normal.
• Be reluctant to move off when standing still or in a tight circle.
• Have an unusual sensitivity to hard ground, with a preference for soft areas.
The Therapy Plan
Approximately 25% of horses will continue to experience foot pain on an ongoing basis after a bout of acute laminitis. As with acute laminitis, the first task is to look for a likely cause and work to eliminate it.
Chronic laminitis may be due to unresolved circulatory or mechanical issues or metabolic disease (see sidebar on this page). Consider all these possibilities for a chronically laminitic horse and ensure that each has either been eliminated or corrected with appropriate therapies and management changes.
In addition, all horses that have had a laminitis episode should be checked for concealed abscesses. Burney Chapman, a farrier renowned for caring for laminitic horses, often stated that a drainage of abscess collections was expected 10 days to two weeks following a bout of laminitis. If this hasn’t happened, continued pressure from these collections must always be considered a possible cause of ongoing pain.
The abscesses in a laminitic foot aren’t necessarily collections of infection, although they can be. Usually, they’re fluid pockets that develop in areas of damaged laminae as a result of the inflammation and dead tissue. If the initial pockets of fluid don’t drain, or if there is ongoing damage to the feet for mechanical reasons, abscess formation can be an important source of ongoing pain that needs to be eliminated.
Hoof testers may or may not show sensitive spots, and the soles and coronary bands may also show no evidence of “bruising” or anything trying to break through either. This does not necessarily mean the collections aren’t there. We recommend you discuss with your veterinarian soaking the horse’s feet in warm water and Epsom salts, plus putting ichthammol on the soles and coronary bands/heels just to be on the safe side.
As always, your farrier’s skill is especially critical when it comes to chronic laminitis — both as a therapy and, unfortunately, as a cause. In fact, poor trimming can lead to ongoing damage to the feet and is a common cause of chronic laminitis pain. The two most common mistakes made are: 1) a failure to back up the toe sufficiently to restore alignment of the hoof wall with the coffin bone and 2) leaving the heels too high so that the tip of the coffin bone is pointing down to and pressing on the sole.
Because the foundered hoof will likely grow more quickly at the heels and quarters, a horse with chronic laminitis needs to be trimmed as frequently as every two weeks to avoid heel growth getting out of hand. The choice of whether the farrier treatment includes the use of therapeutic shoeing or just constant trimming should be made by the farrier and treating veterinarian.
Finally, you’re pretty much always battling the effects of an extensive loss of blood supply to the foot. An adequate blood supply is important not only to keep the tissues healthy, but also for the release of growth factors that cause new vessels to grow into areas that need them. As is the case with human diabetics, controlling the diet is a necessity. Inappropriate diets will lead to ongoing spasms and vascular/circulatory problems in the hoof.
It’s also wise to avoid long-term phenylbutazone/NSAID use, since these drugs also could interfere with circulation to the hoof.
Horses that are chronically laminitic — including those that appear to have periodic bouts of laminitis attacks — require a complete management change. Bute administration is little more than a quick fix to quiet things down. It’s likely you’ll be fighting yet another attack down the road.Instead, we suggest this problem be treated as an ongoing disease that requires constant control, again, much like human diabetes. Pay careful attention to the causes, identifying and limiting all possible triggers. If your horse worsens at particular times of the year, figure out what changed in his environment and/or barn management practices and eliminate any changes that might be laminitis causes. Approach the situation in a manner that allows you to identify exactly what’s helping and what makes no difference.
Chronically laminitic horses with known Cushing’s disease, insulin resistance or a history of grass-induced laminitis should not receive grain and require a strict limitation of sugars and starches, including grass (watch for “Limiting Sugar And Carbs Works For Horses, Too” in an upcoming issue). If they need more calories to hold their weight, opt for adding beet pulp and maximum hay.
We’re wary of high-fat diets for these horses. Fat worsens insulin resistance in ponies, although studies have not determined if it’s truly a risk factor for horses, too.
Be careful with grass, especially in the spring and immediately after a frost, when the sugar levels in grasses are at a peak. If the horse is overweight, encourage a slow but steady return to normal by feeding primarily hay, at a rate of 1.5 to 2% of what the normal body weight should be.