Insulin Resistance (IR) is a metabolic type, not a disease…

Posted in: Health, Stories & Thoughts, The Journey – Dancer

A huge thank you to Heather Richardson of Amberley Aromatics for kindly allowing me to publish her article on IR. Heather provides a fabulous service of balancing horses diets precisely to your individual hay and pasture analysis. This is the only way to be absolutely 100% sure your horse is getting absolutely everything they need in terms of the correct levels of vitamins, minerals and calories.

Huge numbers of horses now suffer from Insulin Resistance (IR), yet many people have never even heard of it. It’s concequences if a low sugar and starch diet is not adhered to can be catastrophic since it puts those horses at a much higher risk of developing laminitis. My own horse Dancer has IR.


IR is a metabolic type commonly found in native good-doer type breeds when not being exercised. This includes Arabs, native pony breeds, some Warmbloods, Draft breeds, Icelandics, many Morgans, some Saddlebred lines, the Peruvian Paso and other horses of Spanish descent. Ancestors of some of these breeds often evolved on sparse vegetation and needed a survival edge for the winter.

What happens?

With IR, glucose has a harder job being burned as a fuel in the muscle and ends up instead in fat. The ability to easily pack on fat is a survival advantage. When fed diets too high in sugar or starch, these horses not only get fat very easily they also develop very high insulin levels. Like “pre-diabetes” in people, this can lead to health problems, the most devastating of which for the horse is laminitis. To correct this, it is necessary to limit the levels of starch and sugar in the diet.

Low sugar and starch levels

There is some individual variation in their sensitivity but generally the combined sugar and starch level should be kept below 10%.

Feeds to use which are under 10% sugar and starch:

Other low sugar/starch soaked feeds 

Low sugar chaffs

Cubed feeds


Feeds to avoid

Be careful when looking at feeds that marketed as low sugar and suitable for laminitics.  Look at the sugar and starch levels and make sure they are 10% or below when combined.  If they are not, best to avoid them.  Also look for feeds that have been approved by the Laminitis Trust Fund.