A coordinated approach to equine insulin dysregulation

Nutritional management advice is not uniform

insulin response to ingested nonstructural carbohydrates (i.e. starch, simple sugars, and fructans, and/or exaggerated insulin response to intravenously provided simple sugars). Horses or ponies with ID are at increased risk of laminitis, and diet is central to managing any animal with ID.

Obesity, age, and breed type play a role in horses’ increased risk of ID. Unfortunately, it is impossible to look at an individual horse/pony and state categorically they are or are not ID. Diagnostic testing is, therefore, essential, not only for identification, but also for monitoring purposes. Choosing the appropriate test, as well as regular monitoring, is often key.

Nutritional management advice is not uniform, especially because not all ID animals are obese and, therefore, the nutritional goal could actually be weight gain rather than weight loss. Not all horses and ponies show the same insulin response to a particular diet. The response will likely vary with many factors, including the time of the year.

Therefore, diagnosing and managing a horse/pony with ID can be challenging for many reasons, and a coordinated approach between the owner, treating veterinarian (and possibly specialist/referral veterinarian), the diagnostic laboratory, and the nutritional advisor can often be beneficial, especially in the more complex cases. Supporting the advice provided at all points is background peer-reviewed scientific research.

The treating veterinarian is central to this coordinated response. They need not only to recognize the potential for an individual animal to be ID, but they need to work with the owner/caregiver to develop a plan targeted to the individual animal—taking into account what feeds/forages are available, as well as any constraints around facilities/ equipment, etc. The owner/ caregiver must “buy” into the plan to understand the importance and relevance.

The treating veterinarian, or consultation with a specialist veterinarian, needs to choose the best test(s) for an individual based on current research and recommendations.4,5

Additionally, it is best to use an equine-specific laboratory that is knowledgeable in areas utilizing validated laboratory assays. The laboratory needs to provide guidance as to the interpretation of the laboratory results based on current recommendations backed by leading researchers.1,2 Having a nutritionist who is experienced in managing such cases within your support team and up to date on the latest published research is helpful in deciding what diet to feed, especially when things do not seem to go to plan.

Feeding and management

The following tips are helpful for improving insulin sensitivity and reducing insulin response to the diet3:

Remove cereal grains and sweet/complementary feeds that have a high/moderate nonstructural carbohydrate (NSC) (i.e. starch, simple sugars, and fructans) content from the diet. Feed multiple small, low NSC providing meals/day. The maximum NSC intake level/ meal may depend on the individual6 and how low a postprandial insulin response is required.

Restricted or zero access to pasture may be required.

Feed a diet based on grass hay (or hay substitute) with a low NSC content (less than 10-12 percent DM), together with a fortified forage balancer.

Feed for maintenance of moderate Body Condition Score (4.5-5.5/9 BCS)—this may require a weight loss/weight gain or maintenance diet.

Increase free and/or structured exercise (if clinically/practically possible).

Feeding and management advice should be guided by clinical situation and laboratory results: monitoring is key.7