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How to Successfully Pasture a Foundered Horse or Pony

We have been raising animals on our farm for over 12 years and enjoy providing the best possible care for them.

laminitis-founder

If our pony was a car, she would be a real lemon. While she is an adorable animal, she chokes on hay, dirt, and long grass, and she also suffers horribly from founder during the spring and summer.

What Is Founder?

Founder is a very painful condition where blood flow is cut off to the hoof resulting in inflammation, lameness, and other serious hoof problems. It is triggered in susceptible animals when the horse or pony eats grass that contains large quantities of starch and sugar.

When a vet utters the dreaded word “founder”, most equines are immediately fed hay in a dry lot or put onto overgrazed pastures with little to no grass. While this drastic treatment is sometimes necessary, most horse and pony owners sentence their equines to this dreary fate without fully understanding what founder actually means.

Let’s learn how to keep grass-foundered horses and ponies on pasture all year round.

Donkeys can suffer from laminitis, too

Donkeys can suffer from laminitis, too

Founder, Laminitis And Your Equines

A horse’s hoof contains roughly 600 laminae, which are soft tissue that connect the coffin bone to the inside of the hoof wall. The coffin bone, also called the pedal bone or third phalanx (P3), sits behind the hoof wall at the front of the hoof capsule and is an integral part of an animal’s hoof. Here is a great site that shows the detailed anatomy of equine hoofs and the position of the coffin bone (WARNING: this link contains anatomical images that some might find graphic).

The bond between the laminae and the coffin bone is strong enough to bear the full weight of the animal while it is running, yet still being flexible so the hoof can grow around it.

When a is horse stricken with founder, blood flow is cut off to the laminae causing inflammation and death of the tissue. As the condition worsens, the coffin bone can loosen from the hoof wall and twist downward or even punch through the sole of the hoof. It can be an acute issue, or it can turn into a long-term chronic condition.

Founder is extremely painful for equines. It is akin to ripping out your toenails and then walking tiptoe while carrying a 500kg (1100lbs) backpack.

Founder vs Laminitis

There is great debate amongst veterinarians and equestrians alike about what founder and laminitis actually mean. Some say founder refers to more severe cases, while others say laminitis is acute while founder is chronic. Others claim that founder only applies to the rotation or sinking of the coffin bone.

In this article, we follow the more common vernacular and use these terms interchangeably.

Causes of Laminitis and Founder

For most equines, founder is caused by eating grass at the wrong time of the year and at the wrong stage of the grass’s growth. This is called grass-induced founder, or pasture-associated founder.

Founder, or laminitis, can also be caused by:

  • The horse overeating grain
  • Overworking the horse or hoof concussion on hard surfaces
  • When a hot horse drinks cold water (also called water founder)
  • Uterine infections (called post-parturient laminitis)
  • Unresolved hoof injuries, or improper trimming
  • Septic infections
  • Severe diarrhea, colic, or other intestinal diseases

There are also other more obscure causes, and founder has been reportedly caused by respiratory infections, certain drugs, and even eating too many beet greens.

Make sure to talk to your vet to know what kind of founder you are dealing with. In this article, we are talking about grazing ponies with grass-induced founder, and these suggestions could further exacerbate other types of laminitis.

Symptoms

Laminitis can affect any hoof. It can afflict the forefeet, hindfeet, or all hoofs at once. If you notice any of these symptoms, your horse may be suffering from laminitis:

  • Lameness
  • Obvious pain
  • Reluctant to walk
  • Stiff or painful gait
  • Legs stretched out, or directly under the body to shift weight off of sore hoofs
  • Inability to stand
  • Hoof wall grows very quickly. Since the toe grows faster than heel, foundered horses will often develop a long curled hoof. Hoofs will often buckle or twist sideways

If you suspect founder, call the vet right away.

How Grass Growth Affects Founder and Laminitis

Founder from eating forage occurs when an equine eats grass or legumes that are high in nonstructured carbohydrates (NSC). These carbohydrates consist of fructans, sugars, and starch. When a horse eats a lot of NSC, the carbohydrates end in the hindgut where they ferment and inhibit blood flow to the hoofs. Here is a scientific article detailing this process.

While sugars, starch, and fructans are always present in grass, concentrations of these carbohydrates are especially high when:

  • The grass is in direct sunlight: Starches and sugar are produced via photosynthesis which requires sunlight. Grass will have more NSC when the weather has been warm and sunny, or when it grows in full sun.
  • The grass grows quickly: Fast growth requires lots of sugar. The faster the grass is growing, the more sugar it will have. Lush growth in the springtime is especially bad.
  • Later in the day: NSC levels are higher in the late afternoon and early evening because the grass has had all day to produce sugar. As the night progresses, the NSC levels decrease as the plant consumes them or converts them to sugar.
  • Days are hot and nights are cool: Plants produce sugar during the day. During the night, the plant will either consume the sugar or convert it into starch. When the nights are hot, the plant will consume lots of the sugar produced during the day to sustain itself. When the nights are cool, however, it won’t need very much sugar during the night so there will be more sugar left in the plant when morning comes. Again, spring is especially bad as the days are heating up but the nights stay cool.
  • The bottom of the stalk: Most of the sugar is stored in the bottom 7cm to 10cm (3-4 inches) of each blade.
  • The forage has formed seed heads: Seed heads, even before they have emerged, contain a high concentration of sugar.
  • After a frost: When grass frosts but has not yet become dormant, the forage will contain high levels of non-structured carbohydrates and can be very bad for horses and equines.
  • Stressed plants: Drought, poor soil nutrition, killing frosts, herbicides, or overgrazing results in the slow growth of the grass. Even though the plant is growing slowly, it still photosynthesizes and produces sugar, meaning there will be the same amount of sugar concentrated in a smaller plant, which equals more sugar per bite.
  • Obesity: Animals that are overweight are more prone to founder.
A pony on pasture

A pony on pasture

8 Tips to Keep Your Foundered Equine on Grass

It may seem contradictory, but with careful management, pasture-foundered horses can be kept on lush, green grass!

Here are some ways to keep your foundered ponies out on pasture:

1. Call the Vet

While many vets will not recommend pasturing foundered animals, your first action when you find your equines suffering from laminitis is to call the vet for a proper diagnosis and care plan. In some cases, anti-inflammatories or pain medication might be necessary for the overall well-being of your animals.

Also, many foundered horses, especially at the onset of the infliction, should be stalled and not allowed to walk. If the acute case is serious, they will probably need a dry lot or stall rest until the inflammation is under control before the animal can be returned to grass.

Always follow the guidance of your vet before putting your foundered animals on pasture.

2. Find a Good Farrier

Foundered hoofs will grow quickly, and the hoofs will become long, curled, and twisted. On top of aggravating the founder, this can also damage the horse’s tendons and ligaments in the hoof and leg causing further pain and stress to your animals. We have a farrier come every 8 weeks all year long.

It is very important to find a good farrier who understands foundered animals. We went through four farriers until we found one that knew how to properly trim our foundered pony.

3. Graze on Cloudy Days

Since grass produces more sugars and starch when the sun is shining, pasture your animals in a shady pasture. If one of your equines is susceptible to founder, set aside a treed pasture to graze them in during seasons when photosynthesis is at its most intense.

Alternatively, research in the United Kingdom has found that the NSC levels in pasture were significantly lowered after 2 weeks of cloudy weather, so the animals can graze a little freer when the weather has been cloudy.

Grass growing in the shade of trees contains less NSC

Grass growing in the shade of trees contains less NSC

4. Graze From 3 AM to 10 AM

During the early hours of the morning, a grass’ sugars and starches are at their lowest levels and the ideal time to graze your animals is between 3 and 10 o’clock in the morning.

Incidentally, the worst time to graze your foundered animals (when the NSC is at its highest) is in the late afternoon and evening because the grass has had all day to produce sugar.

Since getting up at three in the morning to let the ponies out was impractical, we let our ponies graze from 5 am to around half past 10 in the morning.

5. Pick Grass

If you have to keep your horses in, you can pick grass for them instead of keeping them exclusively on hay. Pick the grass early in the morning when the sugar content is at its lowest, and then store it in the shade until it is needed.

Make sure to put the picked grass into a hay bag (see below).

6. Carefully Rotate Pastures

Pasture rotation is the practice of moving your animals into different pastures throughout the year to control the grass’s height. This can help reduce the chance of founder.

Ideally, you want to move your animals off a pasture before they graze it down too short, but you want to make sure they graze all the pastures so they do not go to seed.

Horses are notorious for picking out the sweetest grass. Once an area is grazed down, the regrowing grass will be sweeter, and the equines will continue to overgraze this short area and leave the other areas to over-mature. Rotating pastures will prevent this overgrazing.

Careful pasture rotation will also improve soil fertility, which will help maintain healthy NSC levels.

Here is a good article that discusses pasture rotation for your horses in more detail.

7. Use a Grazing Muzzle

Grazing muzzles are a very controversial horse management technique, but they are literally a lifesaver when it comes to keeping foundered horses on pasture.

Grazing muzzles are designed to reduce an equine’s intake of grass. For foundered horses, this means they can still eat grass, but they cannot eat enough of it to overload their guts with sugar and starch. In many cases, this means you can leave them out on pasture when you would otherwise have to lock them up and hay feed them.

Here are a few pointers when using grazing muzzles:

  • Keep the grass shorter: If the grass is too long or too short, they cannot get it in the muzzle and they will have a very difficult and frustrating time trying to eat. Ideally, the grass should be around 10cm (4 inches) give or take.
  • Don’t leave them on all day: Grazing muzzles should only be left on for a maximum of 10 hours each day.
  • Watch for behavioural changes: It is unlikely that your horse or pony will love their grazing muzzle. Animals will sometimes start displaying inappropriate or aggressive behaviour because of their new tackle. Our pony started to become aggressive as a result of her muzzle. It took a few days of training for her to learn this new behaviour was unacceptable, and after a while, we found it necessary to take a break from the muzzle before using it again.
  • For horses and ponies only: Grazing muzzles are not usually suitable for donkeys. Due to the way they graze, a donkey is more likely to get their muzzle tangled or snagged, and while most contain a breakaway clasp, this can still be very dangerous for your donkeys.

8. Use a Hay Bag

Equines can also founder on hay, especially if your hay has a high clover content. The first time our pony had a serious acute case of founder was during the winter, and feeding her with a hay bag was the best course of action.

Hay bags are large mesh bags that limit how fast your animals can eat. They come in different sizes and with different size holes depending on the eating needs and size of your critters. For us, hay bags are imperative in the winter, but they are also necessary in the summer, too. If you feed your animals hay or picked grass in their stall or dry lot when they are not on pasture, consider putting it in a hay bag to limit their intake and further reduce the chance of them foundering.

Equines can founder in winter

Equines can founder in winter

Foundered Pony Grazing Plan

When our pony was diagnosed with laminitis, we followed our vet’s advice until her acute symptoms had significantly improved. After that, everyone told us that she would never be able to graze on pasture again. However, by incorporating the tips we mentioned above, we were able to not only have her out on pasture but were rewarded by seeing her gallop through the field on her once-stricken hoofs.

Here is the grazing plan that we follow with our foundered animals:

5 AM to 10 AM: Put out to pasture (without a grazing muzzle).

10 AM to 9 PM: Put on dry lot or stall. (We were able to use an overmature pasture that was full of dry grass from last year).

Overnight: Put out to pasture WITH a grazing muzzle.

This regime is fairly rigorous and can be especially difficult depending on your work or school schedule. Remember, this is just an example of what we did to keep our animals on pasture as much as possible. Feel free to experiment and find the right routine for you and your equines.

The Challenges of Grazing Equines

Since founder is caused by grass, many people think that putting their horses on a closely cropped pasture where the grass is eaten down to the dirt is the solution to founder. However, by keeping the grass cropped short, the forage stays at a constant state of fast growth (and thus full of sugar). Furthermore, by eating the grass right down, it is more likely that the equines will snort or ingest dirt, causing further health complications.

I hope this article has given you some hope that your horse or pony will one day be frolicking on pasture with the herd once again.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

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