What causes laminitis?
Our understanding of the cause of laminitis has improved dramatically over the last 5 years. Historically it was always thought that access to new pasture was the primary cause for laminitis, but this didn’t explain the common situation of two horses being grazed on the same field but only one developing laminitis. Clearly grazing plays an important role in triggering laminitis, but the fact that some horses are susceptible whereas others appear not to be tells us that there must be factors within each individual that affect whether or not he/she might get laminitis. So what are these factors?
90% of laminitis cases however have an underlying hormonal cause, and it is this hormonal cause that determines whether they will develop laminitis when they are turned out onto new pasture.
The exact mechanisms whereby hormonal diseases cause laminitis is currently unknown, but what we do know is that there is a complicated interplay between three hormonal conditions called PPID, EMS and insulin resistance which increases the risk of an individual horse developing laminitis.
An individual horse can have EMS and PPID concurrently, and therefore it is usually worth testing for both conditions.