What Is Horse Founder?

Horse founder is a disease that affects the laminae. The laminae are layers of modified skin cells surrounding the bone of the hoof. Laminitis manifests as a blockage in blood flow in and to the lamina. The lack of oxygen and nutrients carried by the blood will damage the affected lamina. The anemic lamina will become inflamed in the long run.

So, when inflammation of the lamina occurs, the hoof and the feet of the affected horse will suffer. The horse afflicted with such inflammation will begin to feel pain. The degeneration of this case will lead to the gradual death of the lamina. This increases the severity and intensity of the pain.

It might be so bad to the extent that the hoof will no longer support the pedal bone. This has caused lameness for horses. It can affect any of the legs. Founder is different from any other equine disease. It can cause permanent damage to the affected leg. The welfare implications of this to the horse and its owner can be huge.

An experienced veterinarian, William Moyer, makes a remarkable comment about this disease. He says: “Laminitis is one of the most complicated diseases there is. You can’t always accurately predict what will happen from one day to the next, much less a month or a year from now.” If you understand what horse founder actually is, you will agree with him. 30 years of experience in treating countless foundered horses has taught him a lot.

Causes of Founder

To avoid or reduce cases of laminitis, it’s important to understand the real causes. But the causes of laminitis are still not understood in full. In fact, the words of Moyer quoted earlier gives that hint. He actually confessed: “There are times when we’ll never know what caused a horse to founder.”

Laminitis may follow a certain incident in the barn or pasture. It may trail a treatment carried out on a horse. For instance, it may follow a colic surgery. That doesn’t mean the surgery caused founder. It may inflict a horse fed on large amounts of grain the previous night. That doesn’t indict the grain.

Research has shown that many factors or a combination of them can be responsible. This problem can start from places far from the hooves. In most cases, farriers and veterinarians seem to agree on nutrition as a big factor in founder.

Many horse owners allow horses and ponies with a large appetite to graze on lush pasture for too long. They can overeat and gain too much weight with time. Uncontrolled access to carbohydrates is one of the common causes of laminitis. This is because there will be an overload of undigested sugars and starches.

Other than nutrition, other causes include diseases linked to inflammation. Colic and diarrhea are common factors. Enteritis may occur if a horse takes in large amounts of cold water.

If the placenta doesn’t come out after a shire horse foal, it will cause founder. This may be more severe if the horse gets stressed with long traveling. A change of environment in the process can also be an issue. Pneumonia can also traumatize the soles of horses’ hooves and cause laminitis.

Hormonal imbalance is also a big factor responsible for founder. For instance, a horse may founder due to PPID (pituitary pars intermedia dysfunction). This is also known as Cushing’s disease. PPID is a form of Cushing’s syndrome. It results when the pituitary gland produces an excess amount of the hormone ACTH. This will increase the horse’s hunger and thirst. Profuse sweating and weight loss will follow. There are many other endocrine issues besides excessive pasturing.

There is another cause identified as SSL (supporting limb laminitis). This is another description of mechanical overload as a result of a fracture or infection in a joint. The pressure will be on an otherwise healthy leg to bear the remaining weight. This may bring the horse down with laminitis.

A horse made to walk too fast or work hard for a long period is at risk as well. It may founder due to the excessive pressure on the leg.

Systemic infection may result in toxemia or blood poisoning. Bacterial infections are common to horses. High fever or a similar illness may turn to an EMS (equine metabolic syndrome). This is another common cause of founder in horses.

Other causative agents are:

  • Nitrogen compound overload
  • Frosted grass
  • Insulin resistance
  • Untreated infections
  • Exposure to chemicals
  • Drugs adverse effect

Phases of Laminitis

Before coming up with a treatment option or prognosis of a case of equine founder, it’s good to identify the different stages of infection.

1.  Developmental laminitis

This is the earliest phase of foundering. This is the best time to nip the situation in the bud. It’s the period between the initial incident or exposure to a causative agent and the beginning of founder. If it’s discovered at this stage, the effect and cost will be minimal. This phase lasts for 24-60 hours. By initiating mere cryotherapy, you can prevent clinical laminitis. Constant application of an ice pack for a few days in the developmental stage will cure it.

2. Acute laminitis

The continued equine founder infliction beyond the first 60 hours is generally considered acute. The response and progress within this period to 72 hours is important to the next stage of treatment. It has progressed to the chronic phase if the horse’ response to the hoof testing is sharp. Digital pulses, heat, and even lameness may result. It can be life-threatening. So veterinarians consider this state a medical emergency.

3.  Sub-acute laminitis

A case of founder is sub-acute if it reverses after a small series of treatments in the acute phase. In this case, the damage to the lamina is minimal. The foundered horse becomes sound again and never shows any radiographic change. There’s no injury to the horse’ bone in the sub-acute phase.

4.  Chronic laminitis

It’s possible for a horse that has gone through a previous bout of laminitis to founder again. Also, an uncontrolled developmental founder can graduate to acute and even chronic phases. The recurrence or continuous low-grade laminitis is often diagnosed as a chronic founder. When it has become chronic, the foundered horse lamina will be damaged. The coffin bone may be somewhat displaced. The dermal and epidermal laminae may separate while the dermal lamina becomes elongated. This compresses the coronary and solar dermis. The damage may become permanent.

Early Signs of Horse Founder

It’s now clear that early detection of laminitis is important. Your horse stands a better chance of beating this hoof disease if you are able to nip it in the bud. The following are the warning signs that should put you on your toes once you observe them in a horse.

1. An Abnormal High Hoof Temperature

It’s not a big deal if your horse’s temperature increases a bit. Horses do experience a voluminous flow of blood into their feet from time to time. This will increase their body temperature. Their bodies are capable of regulating this temperature within hours. It’s alarming only when the high temperature persists. It’s more so when the outdoor temperature doesn’t increase.

As a general rule, you have to worry when your horse hooves are over 33° Celsius. The exception is if the outdoor temperature is 25°C or more. It may take less than 24 hours before the ensuing laminitis results in lameness. So it’s good to have an infrared temperature gauge handy.

2. The Presence Of A Stronger, Increased, Or Bounding Digital Pulse

The digital pulse of a horse will give you a hint about the closeness or presence of founder. You will know by sliding your hand down the side of the horse’s lower limb. This is the digital artery passageway. It runs through the groove adjoining the suspensory ligament and the flexor tendons. You can feel the pulse where the artery runs down the fetlock back. You may not feel any pulse or feel it faintly.

If a horse founders, the pulse you will feel will be stronger. That’s why it’s called bounding pulse. If you’re used to feeling your horse’s digital pulse, you should know when it’s stronger. Although it’s not enough to diagnose founder, it might be a sign of other foot pain. But it’s a clue.

3. Shortened Strides

This is one of the earliest signs of equine founder. It’s common for a foundering horse to move with short strides hours or days before it starts limping. By watching each horse as they turn, you’ll be able to tell if the strides have changed. Laminitis is one of the few conditions that cripple horses on hard ground.

If you’re observant, you’ll recognize it when the strides of your horse have shortened. If a horse pins its ears while turning, that’s a sign of pain. They may also feel reluctant to move in a changed direction. They may appear okay on soft ground and a straight line. But does movement or disposition change when it has to turn or reaches harder ground? That’s a sign.

4. Increase In Insulin Levels

Horses’ bodies also have the hormone insulin, this regulates their blood sugar. But this hormone also activates IGF, a particular growth factor in the laminae. If the insulin level is high, laminae will grow. That portends the danger of laminitis.

Normal insulin level should not exceed 20 units. A reading of 40 units of insulin needs urgent action. You must get it down before the horse starts foundering. But, between 20 and 40 units is considered a grey area. An oral glucose test can help. You can give the horse a high dose of corn syrup which will spike the insulin level. In one to two hours, the insulin level will come down, returning a healthy horse. This will take longer in an insulin-resistant horse.

5. Increased Heart Rate

Andrew van Eps, is a senior lecturer and an equine medicine specialist. He practices at The University of Queensland Equine Hospital, Gatton, Australia. He shares some insights on this: “We used to think that heart rate was not a very sensitive indicator. But we found that in our clinical patients the most sensitive indicator (for pending laminitis) is probably an increase in heart rate.”

The normal heart rate for most horses is 30-40 bpm (beats per minute). But Andrew van Eps says: “A mild increase in heart rate of even 6 bpm can be a significant early indicator that your horse is getting uncomfortable.”

6. Unusual Rings Or Distorted Hoof

You need to be familiar with the normal growth pattern of hooves. In healthy horses, the hooves grow faster in the dorsal. The growth is slower in the quarters. That’s why the growth of the ring across the front of the hoof wall will be smooth, wide, and evenly spaced.

But when founder sets in, there will be an alteration in the growth order. The heel’s growth becomes more rapid than that of the toe. So, there will be wider growth rings at the heel area. The affected hoof’s ring will curve up. There will also be an abnormality in the rings on the hoof wall. This may happen in some horses even before any sign of pain.

7. Changed Rate of Foot Lifting

If a horse is picking its feet up too often, watch it. Laminitis may be close, if the horse hasn’t started foundering. Here is the logic: pain makes the feet restless. If there is pain in the foot, the horse will start changing its stand. It will want to shift its weight to its haunches. The horse is foundering if it is stretching its legs forward.

Again, Andrew van Eps states: “Horses normally shift their (weight between) feet about two or three times per minute. We noticed an increase of three to five times that weight-shifting when they were developing laminitis.”

8. Stretched or Bleeding Laminae

This is a very clear sign of horse founder. When laminae begin to stretch, they will separate from the wall of the hoof. This gap becomes more conspicuous along the white line. This is the meeting point of the sole and hoof wall. During a farrier’s visit, this will be clearer in the trimming of the horse’ foot. Is your horse’s laminae hemorrhaging? If so, they are most likely suffering from laminitis.

9. Obesity

You need professional experience to interpret what obesity signifies in your horse. Donald Walsh is the leader of the Animal Health Foundation, in Pacific, Missouri. He says: “A lot of farriers will think the horse is wearing his feet down from being overweight. The horse is breaking his foot down, not wearing his foot down, due to first, the stretching of the laminae. Then the excess weight helps to break the foot down.”

What can help here is to recognize it if your horse is gaining more weight. Walsh states: “Owners are generally blind to how overweight their horses are and don’t appreciate how much they’re overfeeding.” Help your horse cut down on calorie intake and increase its physical activity.

10. Intestinal Disorder And Inflammation

Much has been said about this while discussing the causes of horse founder. Walsh says: “If the horse is developing a high fever and diarrhea, then laminitis is next on the plate, and you have to be proactive in thinking about that. These horses are engaged in massive destruction of the laminae, which occurs because of enzyme reactions in the feet due to the inflammatory response.”

Besides these 10 clinical signs, veterinary doctors diagnose horse founder using other methods.

  1. X-ray imaging. Vets recommend this if there’s concern about the sinking and rotation of the pedal bone. X-ray is also advised when your horse is not responding well to appropriate therapy.
  2. Blood test. This usually comes up when an endocrine disease is the suspected culprit.

Treatment of Founder

The treatment of founder will depend on the diagnosis, observed signs, and causes. Whatever the choice is, the most helpful treatment is to target the cause. There are various treatment options for laminitis. They are as follows:

1. Dietary restrictions

The laminitic horse should eat for sustenance only for the time being. It should feed on poor quality hay with little or no concentrates. The infected horse shouldn’t graze. Rather, it should eat roughages like sugar without molasses. Hi-Fi feed product will be good at this time.

2. Relocating the affected horse

You must move the affected horse to ensure appropriate box rest. It also needs to be on sandy ground if not on foam.

3. Foot support products

There are various support sole products and special pads. Some of them limit movement of the affected pedal bone. You can use a deep bed extending all the way to the door. There are also various frog supports attached to the leg. Foams and acrylic products can help here.

4. Medications

Vets may prescribe various medications to control the pain. They may want to administer some drugs themselves. Common non-steroidal anti-inflammatory founder medications include phenylbutazone and flunixin.  Examples of opiates for laminitis are morphine and pethidine.

In any case, it’s important to seek the opinion of specialists. Do this before administering any drugs or supplements.

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