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Is it Laminitis or Founder?

"GROWTH RINGS' OR "FEVER RINGS"
Ripples or growth rings indicating chronic laminits
RIPPLES INDICATE A LONG STANDING PROBLEM
CHRONIC LAMINITIS WITH BONE LOSS
Founder and Seedy Toe infection
SEEDY TOE AND SINKER SYNDROME

WHAT FOUNDER AND LAMINITIS MEANS

     Founder or Laminitis are terms that are often used interchangeably by horsemen, however, they do describe two separate pathologies that frequently occur together. Founder is the separation of hoof wall and bone; the tearing of the lamina (what attaches the hoof to the body) dies or is ripped apart. Many of you have heard this referred to as "rotation".  Founder can occur without many dramatic symptoms. Most frequently it's a result of laminitis, but many times can be caused by excessive hoof growth, opportunistic infections (White line disease) or even from shoeing. Foundered horses tend to have thin, flat, or even bulging soles, are sensitive on hard or rocky ground, and tend to have flaring, or "dishing" or "bell" shaped hooves.  Laminitis is the term used to describe the actual inflammation of the lamina, and can can be caused by poor hoof mechanics, excessive, sudden increase in workload (road founder), retained placentas in broodmares, reactions to medications or vaccinations, stress, and mostcommonly, carbohydrate overload.  Laminitis as most people think of it is the acute stage, where the most severe pain is apparent, with severe lameness,resistance to walk (and appears to "walk on eggshells"), or refused to stand or move. If standing, tends to rock back on the hind legs as much as possible and heat is usually obvious with a very apparent digital pulse in the fetlock area. This inflammation may be severe enough to lead to "rotation" of the coffin bone. Laminitis can occur in previously healthy horses through a severe one-time event, such as Old Nelly getting into the grain bin, or be chronic (frequently over a course of time) and mild. Horses with lots of horizontal ripples or growth rings are usually chronic laminitis cases and is a red flag to change this horse's diet or care. Chronic, neglected laminitic hooves will have that "slipper toe" or elf shoe look.

 

THIS HOOF HAD ROTATION ON XRAY
Sinker founder with shoes
FOUNDERED PONY
Chronic mild laminitis, with poor trimming
NEGLECT AND POOR DIET
Classic Slipper Toe Foundered feet with bone coffin bone loss
DISTINCTIVE SLIPPER TOE
FOUNDER "STANCE"
Stance of a pony in acute laminitis.jpg

 Laminitis occurs in four stages;

  • Latent
  • Acute
  • Sub-Acute
  • Refractory

Latent stage is what I consider the calm before the storm, and a good window of opportunity to lessen severity or eliminate symptoms before they begin. From the time of ingestion of the extra grain or whatever trips the body into overload, you have up to 72 hours before the first pain arrives. Right now, GET THAT HORSE MOVING! Walking, gentle riding, slow driving or ponying, even turnout, anything to get the horse moving. Movement will help him metabolize the toxins that will trigger the next phase. Once the next phase begins, stop the excercise. However, at no point should you starve the horse. Give him access to plenty of grass hay. Don't feed any more grain, but if you starve him completely, it throws off his gut flora (healthy bacteria) even more, creating more havoc.

Acute stage, the most painful, lasts up to another 72 hours. This is the one where keeping your horse quiet and calm is most important. While there is active inflammation, do not make him move, esp. in tight turns. Soft, deep bedding, water and hay nearby are the only things he needs. Your vet may prescribe some anti-inflammatory such as Bute to take the edge off the pain, and that is fine during this stage. If possible, any metal shoes should be removed to minimize tearing of the lamina. Foam pads taped to the foot may offer a lot of comfort. Trim any excess hoof wall (have a professional do this) to further minimize tearing of the lamina.If the horse will let you, ice water soaks can help lessen the inflammation.

Sub-Acute stage is the beginning of the recovery. The worst of the pain is over, however, the tissues that were damaged during the acute phase start to die and the hoof wall separates from the bone. This "rotation" is dumps the horse on his sole completely and now the sole is doing double duty of weight bearing and protecting the internal structures. This also puts pressure on the circumflex artery of the hoof, and impeded blood flow. At this point, a trim can now be performed, if you weren't able to do so before. Painkillers should be stopped at this point. It's better for the horse to feel the pain (the tearing of the lamina) to keep him from doing further damage. Hoof boots and pads can be applied, and slow, easy movement should be encouraged. Spread hay out in piles, move the water farther away, and hand walking on firm, flat surfaces (rubber mats are ideal if you don't have hoof boots) for 10-15 minutes and increasing intervals should be started.  Trim every 2-4 weeks.

Refractory stage is hopefully the next one for your horse. This would be the "remission", you could say. With good trims that take the weight bearing away from hoof walls and padding to protect the soles, the hoof will grow down well attached and depending on the amount of exercise, in as little as 9 months the horse could be completely sound (with no further triggers for laminitis occurring and the hoof must be trimmed properly) If not treated appropriately, the horse stays in a sort of semi-permanent sub-acute phase.

 

SINGLE LAMINITIC EPISODE: "SINKER"
SINKER: LAMINITIS FROM WOUND HEALING PROCESS
LAMINITIS IN ONE FOOT FROM INJURY
FOUNDERED DONKEY FOOT
Foundered Donkey Foot with massive fungal infection
ALSO INFECTED WITH FUNGUS

Treatments

   Traditionally founder was thought to occur from the force of the flexor tendon pulling the coffin bone away from the hoof wall, so to treat it, many methods were developed to minimize the pull of the tendon, such as actually severing the tendon or removing large sections of the hoof wall leaving the coffin bone exposed or covered in epoxy. However, recent development of diagnostic imaging used on live horses (think thermo-graphics and MRI) allow us to see the process as it goes on, rather than the dissection of cadavers. X-rays are useful, but can't tell the whole story. I like to describe founder as the hoof wall being pushed up and away from the coffin bone, like a fingernail can sometimes get ripped back. See, the flexor tendon is responsible for flexing the hoof in motion, but there is a counter-force applied by an extensor tendon to keep the bone straight at rest or pull the toe forward in motion. During founder, the extensor tendon is still functioning.Traditional treatments ignore that extensor tendon's hold and assume the hoof wall, or the fingernail, is what is holding the foot in place. However, if you do look at the hoof as a giant fingernail, you can see that my explanation makes more sense than the flexor tendong pulling bone away. If you rip your fingernail back, would you say your finger tip pulled away, or the nail lifted back? The bone in your finger never changed in relation to the rest of your skeleton, your nail is what "let go". Inside a horse's hoof, the other internal structures attached to the coffin bone don't shift from their usual relationship with it, either. Only the outer hoof capsule changes.

Traditionally, treatment for laminitis with founder includes some or all of the following.

  • First, letting the heels grow tall to "alleviate" pressure on the coffin bone by the deep flexor tendon.
  • A shoe is most always applied, sometimes backwards, sometimes a "rocker toe" shoe, to shorten breakover, again aimed at lessening stress by the flexor tendon, which is supposed to minimize the pull of the bone away from the hoof wall. Bar shoes and pads are used to "support" the hoof but they actually slow blood flow and rigid shoes that suspend the hoof off the ground allow the bones in the hoof to "sink" lower, or as I describe, push the hoof further up the leg. Pads used in shoeing are hard plastic, not cushions. They do help buffer the sole from rocks and such, but can pinch the hoof in of themselves. Wooden shoes are recently added to the list, the thought is that they are less rigid than metal. Polyurethane and glue on shoes are also used, and I do think they are an improvement over metal. Any plastic or rubber that completely encases the hoof increases the likely hood of thrush infections, though.  I would like to add that any shoe or covering is lessening any wear of the hoof wall, and can increase leverage on the lamina, and further damage.
  • Surgeries to cut the flexor tendon have been used, and I dare say are not only unnecessary and invasive, but can cause far more damage than they ever corrected.
  • Resection is the partial or complete removal of the hoof wall at the toe, so new, healthy growth can come in well-attached. The problem with this one is that it leaves the coffin bone exposed and is, itself, painful surgery. It does work, but there is a better way to achieve the same mechanical advantage without the risk of infections and trauma to the coffin bone. These last two also invite infections.
  • Drug treatments often include Bute for pain, Isoxuprine to increase blood flow (the hoof often seems to suffer from poor circulation when dumped on the toe as in backward shoes)
  • Confinement to minimize damage, which slows blood flow and hoof growth.

Natural Hoof Care remedies include the following:

  • No drugs. The drugs mask pain that tells the horse he is doing damage,after the acute phase is over, pain is useful and naturally less severe. Drugs upset their bodies chemistry and could make relapse easier.
  • No shoes, but frequent trims instead. As often as every 2 weeks to keep the weakened wall from bearing weight at all. New growth must come in strong to rehab a foundered foot. Hoof boots (much like sneakers)  and foam cushion pads can be used to protect the foot, but are removable for access to trim and don't compromise hoof fucntion, growth or blood flow.
  • Trims will actually lower heels, with a focus to bring the coffin bone back to the appropriate angle with the ground during weight bearing. This takes stress off the lamina of the toe, off the sole and relieve pressure on the circumflex artery. The frog is able to carry more of the burden and bars are left long to share this load. The wall at the toe IS beveled to alleviate leverage on the wall. (The tradtitional idea of easing breakover is correct, but when acheived by high heels, it doesn't work).
  • Focus on correct diet and more exercise is encouraged. Get that horse moving (according to his pain level) to speed recovery and prevent relapse in the future. This may mean a life style change for you horse and I encourage doing some research for ideas. I include a "Tip of the Month" on my website to support good horse care, but also see my Diet and Exercise pages.

Hoof boots are pretty much a must in Founder recovery, unless your entire place and any place you plan to ride is soft sand or rubber mats. A good fit is needed and depending on the amount of hoof distortion (chronic, long term damage causes mis-shapen hooves) the boot size may change as progress is made. In some instances, a special type of cast can be used that is more convenient for the owner in initial healing. Boots should be a standby for any horse anyways, but especially for foundered horses. A foundered horse will not be able to go bare on rocks until a new hoof has grown down and the sole is no longer flat or bulging. Boots will be needed for riding until then. Shoes will not protect the hoof enough and almost always slow healing or reverse it.