Spring has sprung and that means that ponies from all over the southern hemisphere are being shoved into minimally grassed paddocks for fear of the dreaded laminitis. But what is laminitis and is keeping horses lean the best way to prevent it from occurring?

What is Laminitis?

There are three types of laminitis:

• sepsis-related laminitis which occurs when the horse has an inflamed infection that causes tissue damage [1].
• supporting limb laminitis which is usually a secondary issue due to the horse having to stand unilaterally during treatment for a forelimb or hindlimb [1].
• And endocrinopathic laminitis, the more commonly known form of laminitis [1].

 

What Causes Endocrinopathic Laminitis?

Laminitis is caused by insulin dysfunction which is common in horses who have equine metabolic syndrome or Cushing’s disease [1]. When horses with these conditions eat foods with a high amount of non-structural carbohydrates (NSC’s), their insulin levels increase dramatically, which in turn can cause damage to the lamellae, resulting in laminitis [2].

Unfortunately, it is difficult for owners to find out if horses have equine metabolic syndrome or Cushing’s disease without testing. However, a recent study found that certain breeds are more likely to have equine metabolic syndrome than others [1]. Horses that have this syndrome often have fatty deposits, particularly over the nuchal ligament and at the head of the tail [1]. The breeds most likely to have equine metabolic syndrome include [1]:

• Morgans
• American Saddlebreds
• Spanish Mustangs
• Warmbloods
• Pony Breeds

Endocrinopathic laminitis is not limited to horses who have equine metabolic syndrome or Cushing’s disease. Studies have found that some risk factors for laminitis include [3]:

• Being a Mare/Filly
• Increased Age
• Being a Pony
• Obesity (Regional and Generalised)

 

So How Do You Prevent It?

The go-to method for most people is the ‘shove-them-in-a-paddock-and-keep-them-lean’. Of course, It is essential that horses always have something to eat, or else it can cause gut health problems. However, as we know, horses who become obese are more at risk of laminitis.

Dr Nerida Richards claims that it is important to keep glucose levels as low as possible in horses who are at risk of laminitis, and so their diet should have as few NHC’s as possible [2]. While this can be easily managed when it comes to the feed we give them, it is almost impossible to determine how much NHC’s are in a pasture as it can change within the day [2]. However, evidence shows that pasture that is well-irrigated, that doesn’t weather sub-zero temperatures, and has plant species that are considered subtropical, is usually the safest and unlikely to cause laminitis [2].

Exercise also plays an important part in preventing laminitis. In humans, it has been found that exercise improves insulin sensitivity and can reduce inflammation [4]. Related results have been found in ponies, though in both cases it was found that the exercise needed to be more intense than what is usually undertaken [4]. The European College of Equine International Medicine recently suggested some exercise recommendations for horses who are likely to suffer from insulin dysfunction [4]. These recommendations are extrapolated from medical research and clinical studies. They suggest [4]:

• The minimum exercise recommendations for horses who are non-laminitic is low to moderate-intensity exercise (canter to fast canter) for up to 30 minutes, no more than 5 times a week.
• The minimum exercise recommendations for horses who were previously laminitic but have recovered includes low-intensity exercise (fast trot to canter) on a soft surface for up to 30 minutes, 3 times a week.

Laminitis is always going to be feared by horse and pony owners. However, arming yourself with knowledge about the condition and how to manage it is the best way to help your horse.