Researchers Evaluate Field Glucose Test in Ponies

Researchers Evaluate Field Glucose Test in Ponies

Researchers hope the test will help them predict laminitis risk based on ponies' insulin responses to food.

Photo: iStock

Because of their morphology and metabolism, ponies are at particular risk of developing insulin-based laminitis. To help prevent the onset of this debilitating and sometimes deadly disease, owners can have their ponies’ insulin levels checked.

But current basal glucose (sugar) and insulin level testing often doesn’t show intermittent fluctuations (or dysregulations) in insulin levels during feeding, which can also trigger laminitic episodes. That’s why Australian researchers have looked into a new “oral” glucose test that can be mixed in with a pony’s feed ration. If it gives reliable results, it could be a vital tool on pony farms for keeping laminitis at bay. And good news: It does.

“This study suggests that it should be fine to do the test in the field and have reliable results,” said Melody de Laat, PhD, of the Science and Engineering Faculty at Queensland University of Technology, in Brisbane, Australia. There are several oral glucose tests available, however, and the more precise tests will give the most accurate results.

“Of course, you might need to repeat the test a year or two later if things change for your horse or pony,” she added.

In their study, de Laat and her fellow researchers examined the effects of oral glucose (dextrose, also called D-glucose) on eight mixed-breed ponies. They dissolved the powder in water and combined it with wheat bran and lucerne chaff fed in the early morning. Then, they collected blood samples at 90 minutes, two hours, three hours, and 24 hours after the ponies ate the glucose. The researchers performed this same test on three different occasions to be sure they were getting similar results each time—a way to test the reliability (or “repeatability”) of the test. In practice, however, the test only needs to be carried out once.

The team found that test results were reliable because they gave similar results in each pony over the three testing days. Testing at two hours post-consumption was optimal, de Laat said. But the 90-minute test gave fairly consistent results, as well.

She cautioned, however, that not all the ponies seemed to like the taste of the D-glucose, which could be problematic for testing some ponies. But, she added, there are possible alternative sources of glucose that ponies might like better, such as a high-carbohydrate commercial grain product. More research is needed to evaluate such a product’s usefulness in the test, she added.

“The majority of laminitis cases not associated with colitis or injury are due to inappropriate insulin responses to food,” de Laat said. “This means that we should be able to predict laminitis risk based on insulin responses to food in these horses (using this test) and hopefully prevent some cases of laminitis occurring through identification of at-risk animals and implementation of prevention strategies such as dietary modification and weight loss.”

The study, “The repeatability of an oral glucose test in ponies,” will appear in an upcoming issue of the Equine Veterinary Journal

About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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