Twenty years of laminitis research
Did you know that through our work with the WALTHAM Equine Studies Group, SPILLERS has been involved in laminitis research for over twenty years? We hope that by developing a better understanding of what causes laminitis, we can ultimately help to prevent laminitis in the future. With laminitis season now upon us we thought it timely to share a few of our recent highlights along with an insight into some of our current work…
- Excess weight gain as result of feeding cereals was found to reduce (tissue) insulin sensitivity whereas weight gain as result of feeding fat/ oil did not. This research suggested that the source of excess calories rather than obesity per se may have greater effect on insulin sensitivity.
- A recent change in grazing, a move on to ‘good quality' grazing and being a pony of cold blood breed were found to risk factors for laminitis regardless of the season.
- High levels of insulin and low levels adiponectin (a hormone secreted by fat cells that helps to regulate glucose and fat metabolism) in a single blood sample were able to retrospectively predict the risk of laminitis.
- A study found that the threshold levels used for interpreting the combined glucose/ insulin tolerance test (a test used for diagnosing insulin dysregulation) need to the adjusted for ponies.
- Increasing the dose of Karo Syrup used in the Oral Sugar Test (OST), another test used for diagnosing insulin dysregulation, was found to better differentiate between previously laminitic and non-laminitic ponies.
- A study found that the current dose of Karo Syrup used in the OST may not be high enough to detect effectively insulin dysregulation I some horses.
- Insulin response to the OST was found to be lower in autumn, suggesting that seasonally adjusted reference ranges (which are used to interpret results of the OST) may be needed when testing for insulin dysregulation.
- Insulin-like growth factor was identified as a possible link between high levels of insulin in the blood and laminitis. The surface of lamellar cells in the hoof appear to contain no or very few insulin receptors which had left scientists confused about how high levels of insulin may lead to laminitis. However, incubating lamellar cells with increasing concentrations of insulin caused a cross reaction with receptor cells. Furthermore, this could be prevented with an antibody that specifically blocks receptors only. Although more work is needed, this research suggests that targeting receptors may be an option for treating or preventing laminitis in the future.
We are far from having all of the answers and continue to participate in several areas of laminits research including:
- Barriers to implementing evidence based management practices: in order for scientific research to benefit horses and ponies, effective communication of the results and their significance is essential. Current research is investigating the reasons why evidence based management practices may or may not be implemented by horse owners.
- Predicting laminitis risk: In follow-up to our previous work, we are now hoping to improve our ability to predict laminitis risk by following a group of previously non-laminitic ponies every 6 months. In addition, PhD project part funded by the WALTHAM Equine Studies Group aims to identify faecal microbiome patterns and/ or urinary markers that may be able to predict the risk of pasture associated laminitis.