DefinitionTheories and causes

These are the three types of laminitis

what are the most common causes of laminitis in horses, how does diet impact the risk of laminitis, can stress or trauma lead to laminitis in horses, how does insulin resistance contribute to the development of laminitis, what role do infections and inflammations play in causing laminitis, are certain breeds more prone to laminitis than others, how can improper trimming and shoeing lead to laminitis, what is the connection between cushing's disease (ppid) and laminitis, how can overfeeding or access to lush pasture trigger laminitis, can laminitis be caused by overworking or excessive exercise

Laminitis is an umbrella term that indicates that the connection between the hoof wall and the coffin bone is compromised. There are a bunch of possible causes for this problem. We can divide these causes into three groups, which gives us three types of laminitis: hormone-related laminitis, SIRS-related laminitis, and traumatic laminitis.

Know the differences

These three types of laminitis are often grouped together. This increases the risk of misdiagnosis, wrong treatment and wrong expectations. On social media, we find posts describing a specific type of laminitis followed by well-intentioned advice that is not relevant to that type. This can be detrimental if the horse owner follows the advice unthinkingly. It is therefore good to know the differences.

Hormone-related laminitis

This form, also known as pasture-associated laminitis, can be thought of as ‘fat horse laminitis’. It is the most common form of laminitis. Nine out of ten cases (90%) fall into this category. As the name suggests, hormone-related laminitis is caused by hormonal problems. The main hormonal problems are EMS/insulin dysregulation -whether or not as a comorbidity of PPID (formerly known as Cushing’s disease or syndrome), and synthetic corticosteroids.

This type is often referred to as endocrinopathic laminitis. An endocrinopathy is a disease caused by the malfunctioning of hormone glands. So, technically, laminitis caused by corticosteroids is not a form of endocrinopathic laminitis.

SIRS-related laminitis

This form can be thought of as ‘ill horse laminitis’. SIRS stands for Systemic Inflammatory Response Syndrome. This means that there is an inflammatory response of the whole body, which leads to toxins in the blood. These toxins in turn then cause the laminitis. They can be the result of inflammations and infections and of digestive problems, they can be endogenous or they can enter the body from outside. Think of the latter in terms of poisonous plants, polluted drinking water, mouldy hay and medicines.

Another name for this form is sepsis-related laminitis. Especially when bacteria or bacterial products enter the bloodstream. Sepsis is an inflammatory response of the body to an infection so severe that tissues are damaged. Hoof tissue in this case.

toxins, horses, poisoning, symptoms, treatment, prevention, toxic plants, feed contamination, mycotoxins, heavy metals, pesticides, herbicides, chemical exposure, liver damage, colic
Polluted surface water may lead to SIRS-related laminitis

Traumatic laminitis

This form can be thought of as ‘lame horse laminitis’. The cause is a lack of oxygen in the hoof tissue. This lack of oxygen is the result of heavy, prolonged or incorrect loading of the hoofs. Traumatic laminitis is also known as supporting limb laminitis, mechanical laminitis or road founder. Overloading the hooves can be due to:

  • Incorrect trimming or hoof problems (under-run heels, too long bars, too long toe)
  • Toe landing
  • Being shod
  • Excessive movement on paved roads (carriage and police horses)
  • Overweight
  • Stable housing
  • Pain relief (e.g. after an operation)
  • Long distance transport
three types of laminitis, traumatic laminitis, road founder, hoof inflammation, overstraining, hard surfaces, hoof trauma, equine lameness, hoof care, excessive exercise, stabling, weight-bearing stress, hoof support, laminitis prevention, hoof trimming, pain management
Triple increased risk of traumatic laminitis: prolonged mouvement on the road, poor hoof shape, shod
(photo: Arthur Hinton)

How do I tell which one of the three types of laminitis it is?

In all three types of laminitis we see the same clinical signs, such as an increased hoof temperature, reluctance to move, leaning backwards (laminitis stance) and listless behaviour. How do you know which form of laminitis your horse has to deal with? First, you have to look at what has preceded the laminitis. If your horse broke open the feed bin and then stuffed himself with those yummy pellets full of sugar, then you can be sure that it suffers from SIRS-related laminitis. This is also the case if you know that your horse has an infectious disease (e.g. influenza) or an inflammation (e.g. eye inflammation).

An important and clearly observable difference is that with SIRS-related laminitis the horse looks ill, has a fever and watery diarrhea. Toxins circulate in the blood and his whole body suffers from it. This is not the case with the other two types of laminitis.

Hormone-related laminitis

If, in a manner of speaking, your horse already gets laminitis from the smell of grass alone, you should definitely be thinking in the direction of hormone-related laminitis. Your horse has an abnormal reaction (insuline response) to sugars. We often see signs of insulin dysregulation in these horses, such as a cresty neck. They usually have a high body condition score as well.

three types of laminitis, endocrinopathic laminitis, sme, insulin resistance, hormonal imbalance, cushings disease, metabolic syndrome, glucose intolerance, obesity, cresty neck, abnormal hormone levels, ppid, endocrine disorders, laminitis triggers, insulin dysregulation, chronic laminitis, hyperinsulinemia, equine diet management, pasture-associated laminitis, blood sugar levels, hormonal treatment
Waiting for laminitis to kick in?
(photo: Chad Stembridge)

Traumatic laminitis

If you cannot identify any connection with food, it may be that there is overstraining and thus traumatic laminitis. This could be the result of stabling, overweight or efforts from the horse to avoid pain after an operation, to name but a few. Horses that are used intensively in the disciplines of endurance, reining and show jumping are at greater risk too. Incorrect trimming and shoeing may also cause traumatic laminitis.

Blood test

Also, your vet will be able to distinguish between the different forms based on the results of a blood test. To confirm hormone-related laminitis, they will search for abnormal levels of certain hormones, such as insulin, cortisol and ACTH. In SIRS-related laminitis, they will find many white blood cells and antibodies in the blood.

One does not exclude the other

It would be nice and clear if these three forms of laminitis were mutually exclusive. But it’s not like that, unfortunately. There is often overlap and they also affect each other. All three weaken the laminar connection.

Whatever type(s) your horse faces, you should not forget that laminitis is a condition that can have serious consequences. Therefore, always get the veterinarian in if you suspect your horse has laminitis. Always.

You simply love clear answers

Then there’s great news for you. ‘The Laminitis answer book‘ is packed with crystal-clear answers to more than two hundred questions about laminitis and everything related to it. available in both softcover and e-book versions

Share