What is the difference between laminitis and founder?
These 2 terms are often used interchangeably, however, the following gives a little more insight into their definitions.
Laminitis: Weakening of the laminae hoof wall connection - the tissue that connects the coffin bone to the hoof wall inside the foot. Horses and ponies, like us humans are experiencing more and more metabolic issues often from too much feed/inappropriate feed and not enough exercise. The first sign of PPID/Cushing's or IR can often be laminitis. Laminitis can be sub-clinical or low-grade and in our previous email, we discussed these signs. Left unchecked, or unresolved, laminitis can progress to what some call 'founder'. This commonly occurs in cresty-necked, or obese horses and is a great reason why horses should exit winter more on the lean side. There are many varying degrees of laminitis - mild or low grade to severe (founder).
Founder: Often used synonymously with laminitis, but often indicates disease progression if this term is used. Most people use the term founder to show a horse whose coffin bone has come separated from its hoof wall attachment and is displaced.
Not just limited to grass,Carbohydrate/Grain overload can also be a major cause of laminitis. Nutritionally induced laminitis through carbohydrate overload (grain, fruit, snacks, molasses) is another common cause. An excess of starch and sugars overflowing into the hindgut upsets the microflora (bacteria), which in turn, produces lactic acid, increasing the acidity of the hindgut. A toxic environment is created and toxins are released into the bloodstream via leaky hindgut epithelium.
Although laminitis is commonly caused by feed, grass, or grain overload, it is also important to realize that not EVERY case of laminitis is feed or metabolically related. There are other causes such as:
- Snakebite.
- Retained fetal membranes(placenta) after the birth of a foal.
- Toxaemia- Many different causes, but horses that have high levels of toxins in the bloodstream are at high risk of laminitis. Bacterial, viral, plant, chemical and fungal toxins have all been implicated in causing laminitis. Keep an eye on horses that are suffering from fever, diarrhoea, colic (particularly after surgery), pneumonia, and pleurisy. Treatment of the initiating cause must be accomplished before improvement in laminitis can be expected.
- Medications and Steroids- Although controversial, prolonged use or high doses of corticosteroids may contribute to the development of laminitis in some horses. Routine vaccinations have also been known to cause laminitis for some horses, therefore careful consideration needs to be given of the time of year they are given for metabolic-type horses and ponies.
- Trauma- If a horse is injured and therefore is excessively weight-bearing on one leg. Fast or prolonged work on hard surfaces is another cause that has been associated with mechanical laminitis.
WSC, NSC, and ESC - what are these?
What are WSC, NSC, and ESC? These are terms for various carbohydrate fractions in forage or feeds.
- Water Soluble Carbohydrates (WSC) are carbohydrates solubilized and extracted in water. Includes monosaccharides, disaccharides and some polysaccharides — mainly fructan.
- Fructan is a major storage carbohydrate in grasses.
- Non-Structural Carbohydrate (NSC) is calculated by adding Water Soluble Carbohydrate (WSC) and Starch.
- Ethanol Soluble Carbohydrates (ESC) are simple sugars. Only ESC and Starch will cause glucose spikes and insulin spikes.
It is the ESC and Starch levels added together that give the percentage of carbohydrates in the hay. For laminitic, IR/Cushings, or any obese or metabolically challenged horse or pony, this should be under 10%, with the starch portion being 4% or lower.
How much should a horse be fed?
As a feeding guide, a horse should receive approximately 1.5 – 2.5% of its body weight in forage. Therefore on average, a 500kg horse in maintenance up to moderate work should be getting 10-12.5kg or forage (hay/grass from grazing) per day.
If your horse is overweight, then aiming for 1.5% is ideal and if underweight then heading for 2.5% would be ideal. If your horse needs to lose weight, feeding 1.5% of its current body weight, or 2.0% of it's ideal bodyweight (whichever ismore) is recommended.
This is why we have our hay weighers on our site to help owners weigh their hay and feed to know exactly what weight they are feeding.
Horses should never be fed per biscuit, only by weight. For example; a biscuit of lucerne V's a biscuit of pasture hay can be very different and the horse might be getting too much or too little.
This is where a slow feeder comes in handy as it can be loaded up with hay and the horse is able to get the amount of forage it requires.
The right hay is soooo important!
No matter if there is a short period of fasting or if you have ad-lib 24/7 grazing, the MOST important factor is the sugar and starch content of the hay. If your horse has 24/7 access to high sugar hay then you will never get on top of the laminitis and your horse will head on a downhill run to more severe laminitis and eventually 'founder'.
I personally used to get my hay tested by Equi-Analytical/Dairy One in the USA, however it was getting more and more complicated to import the hay to the USA, so I am now quite happy getting it done in Australia with Feed Central.
