Laminitis/Founder in Horses


9 Years
Jul 26, 2010
The takeaway message:

It's spring and the grass is starting to grow. It's time to start thinking about preventing laminitis in your horses. Laminitis can occur at any time of year, but spring is an especially dangerous time as grass is growing very fast in spring. To prevent laminitis:

1.) Restrict spring grazing to 10 min a day
2.) Lock up your concentrates, bagged feeds, supplements
3.) Keep horses slim and in work

Laminitis is also called 'fever in the feet' and 'founder'.

Laminitis affects the whole body, the the obvious damage is in the feet. It often affects the front feet, but can affect one foot or all 4.

It can be from mild to severe. It can cause pain, cripple the horse, even kill it(or require mercy euthenization).

What is laminitis?

Inflammation of the feet (the lamina, or support system, inside the hooves)

What is founder?
The resulting damage - shifting downward of the bones of the foot

Why do horses get laminitis?
Horses are designed to eat small, frequent meals and can't handle overloads of rich feed.

What brings on founder?
--Usually, overeating
--Overworking an unfit horse (too long, too fast, or on a hard surface)
--Poisoning(black walnut, for example), toxemia
--Some illnesses.

How does management affect founder risk?
--Feeding fewer and larger meals of concentrated feeds
--Feeding less hay than recommended
--Not exercising horses regularly
--Allowing unrestricted grazing during periods of fast pasture plant growth(season, rains, fertilizers)

Are certain horses more at risk?
--Almost any hoofed animal can get laminitis
--Overweight horses
--Many small pony breeds and crosses to those breeds
--Horses that have had laminitis before
--Horses with thyroid deficiency, insulin resistance

What are the signs of laminitis?
--Horse is unwilling to move
--If forced to move, horse moves forward with slow, crouching gait, tries to put feet back on ground quickly
--Horse is trying to stand in a way that takes weight off front feet - stands with hind feet placed further forward, etc
--Horse's feet may feel abnormally warm
--Hard digital pulse

What should you do?
--Do not exercise or walk the horse
--Remove all feed
--Bed the horse in supportive, cushioning, but not overly deep bedding
--Start taking pulse, respiration and heart rate hourly - write it down
--You can minimize damage by getting the vet there as fast as possible
--Call your veterinarian and have him/her come out immediately
--Make sure you ask your vet what s/he wants you to do while you wait for the vet to arrive
--Older treatments (bute, ice/cold water) are now questioned
--Banamine is considered more effective now
--Vet must administer mineral oil by tube to get it where it will help(tubing must be done only by a vet or tech)
--Other drugs are used to minimize absorption of toxins, encourage normal blood circulation

How to tell whether it is Colic, Laminitis or Tying Up
-- These 3 have many causes and symptoms in common
-- Sometimes you cannot tell what is happening - then you need your vet there immediately
-- Appropriate treatment is very different for these 3
- You need to know exactly what is is wrong
- Doing the wrong thing can make it far, far worse
--Possible Colic
- History (what happened to horse) - feed change
- Efforts to relieve stomach pressure - rolling, getting up and lying down, stretching, looking at flanks
--Possible Laminitis
- History (what happened to horse) - feed overload
- Efforts to take weight off front legs - hind feet forward, crouching gait
- Hard digital pulse
- Feet feel warm
--Possible Tying up
- History (what happened to the horse) - work after a rest on full rations
- Hard muscles in hind quarters
- Brown urine

How to prevent Laminitis
--Follow feeding guidelines
- small frequent meals
- 1.5-2% body weight in hay per day
- keep amounts of concentrates low
- most of what a horse eats should be hay
- don't make up for missed meals by feeding a large amount at next meal
- stick to a schedule
- make changes slowly
--Keep all horses, ESPECIALLY small ponies, at a slim, healthy weight - learn condition scoring
--Keep horses in an exercise program year round (eating in a pasture is not an exercise program)
--Restrict spring grazing to 10 minutes a day - use caution after heavy rains, fertilizing pastures
--Secure all concentrates like grain, pellets, supplements - door and gate closers help prevent accidents
--Know which plants and trees are poisonous to horses, identify and remove them
--Dispose of moldy, old, spoiled feeds where horse cannot get at them
--Keep pasture fences, gates, perimeter fences in good condition so horses do not get out and over-eat
--Do not use medicines or enhancers that contain steroids except for emergencies and even then, ONLY under the direction of a veterinarian and ONLY if there is no other option.

(these notes are from the Merck Veterinary Manual)
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Great thing Wels.
BUT want to add, from a veterinarian....
Founder and laminitis are NOT the same thing
Equine laminitis is a vascular disease associated with areas of ischemia or hemostasis within the laminae. The laminae secure the coffin bone/distal phalanx to the hoof wall. Inflammation associated with delamination interferes with the wall/bone bond.
In advanced cases, the coffin bone becomes detached from the horny wall and may rotate or sink. In lay terms, this is known as “founder,” from the maritime term meaning to sink.

A horse can get laminitis and recover with very little or no issues, in founder it can be an excruciatingly painful thing, and may even result in the horse having to be put down.

A very helpful way of preventing either thing from happening..
Not only limit turn out, but MOW the grass a day or so before letting them out on it.
In the case of ponies and overweight horses, put a grazing muzzle on them too.
Yes, I understand that founder and laminitis are not the same - while recognizing that many people use the two words interchangeably, I tried to use the definition laminitis as the 'inflamation of lamina' (though many more structures and processes are affected) and founder as - the shifting downward of the bones of the foot - you'll see that at the top under 'what is laminitis' and 'what is founder'.

I also tried to avoid a lot of terminology that might confuse new horse owners or just those who don't tend to use a lot of technical terms - it was very hard to take the Merck notes and try to do that with them. It was also hard to try and put in key information, not gloss over anything, yet still have it readable. I tried formulating a 'takeaway message' to the top to try and summarize - am working on that for the colic post too.

I love all the terminology, like a typical geek, but it can be hard for others to wade through it.

I've been reluctant to recommend mowing a day before because of other factors, variations in climate, etc. I and several of my friends have had very heavy mold develop on pastures that were long cut and then wet - but of course it can also simply mat and ferment, which is bad enough itself - we had a number of cases like that where I used to board. My friend's horse got neurological (brain) damage on top of colic when she long mowed a rye pasture that subsequently got wet.

We actually had to hand rake out several acres that molded very severely when it was long cut, and then we had to puzzle over what to do with it as it wouldn't compost. I absolutely could not believe the amount of mold. It was incredible.

Another trouble area is dumping bad bales in a corner of a field. Another gal I knew dumped a bunch of bad bales off where they thought the horses would leave them alone - the horses ate a fair amount of it, she lost 2.
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Great information! I do question this one, tho:

--Restrict spring grazing to 10 minutes a day - use caution after heavy rains, fertilizing pastures

I'm thinking this is great advice for horses who have not seen a blade of fresh grass since fall, but lots of us in the Deep South have green grass all year 'round. For us, this would be overkill. The horses are already accustomed to grazing so they will need some restriction with the flush of new grass, but not to 10 minutes a day! Personally if the pasture has been newly overseeded or fertilized, I restrict grazing to half a day for a week or two. If it hasn't, then I don't usually need to do anything special in the springtime. I do watch closely and check feet daily, though. Probably the better general advice would be to talk to your local ag agent or vet school clinic to get recommendations specific to your own area for all matters of grazing and hay quantity/quality, since this does vary so widely across the US and Canada.

Great article!


I understand some places have grass all year but I am not comfortable recommending restricting grazing for a few days only, even in that case.

I worked on a farm down south breaking horses, where the horses were on grass pasture all year and it grew as you describe. They were restricted for a couple days as you describe. Every single one of them had laminitis every spring until they were humanely destroyed.
I have a 6 yo mustang and a healthy pasture. NOT a good combination. I was just thinking yester, "time to get the grazing muzzle out and check it over."
There ya go! That is just so good to hear.

My friend's stocky mustang was one of the 'easy keepers' ever, and she had a muzzle on him most of the year, LOL! He was like a giant vacuum cleaner when it came to that lovely lush spring grass.
Thoroughbreds? Maybe the difference is that I have (and have always had) quarter horses? I dunno. We never get so much as a warm foot. Even when I moved the whole crew from Colorado to Florida in the dead of winter and we used the above system, we had nary a problem. (But then, we've never had any kind of foot problems.) Which is why I suggest the recommendation should be made by a local vet school clinic. Each area of the country and each breed of horse is soooo different that *I'm* just not comfortable with any kind of blanket recommendation. (oh, and I said a couple of weeks, not days.)



Edited to add:

I'm an old man so lots of my methods are considered old-fashioned and out-of-date, BUT I was taught that a hay field should test at 15% protein but the pasture should only test at 10%. That pastures are only fertilized at half the rate of the hay fields. Oh, and hay fields are NOT for grazing, while it IS okay to hay your pastures if you have too much growth for the horses to keep up with. That you never mow a WET pasture because of the danger of molding. (Most people already know not to mow a wet hay field but apparently they don't transfer that logic to their pastures.) That every operation needs a dry lot for the times that the pastures have just been mowed or fertilized, the livestock has been wormed, or you need to keep the livestock off grass for a bit. These are just old-fashioned common sense things that apparently have gotten lost over time.
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Not where I'm at. We are getting about 5-8 inches of snow--I just love winter...not. It is really starting to feel like it will never.freaking. end!!

But, back on topic, I have actually witnessed post-surgical founder. I don't know what the deal was, if it was the facility or what, but was definitely an experience.

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