Evaluation of oral sugar test response for detection of equine metabolic syndrome in obese Crioulo horses.

This study investigates the use of oral sugar tests to diagnose equine metabolic syndrome in obese Crioulo horses, as these animals are often at risk of obesity-related health issues. The research discovered significant bodily measurement and metabolic variances between the control group and obese horses with the latter displaying delayed glucose response and high insulin levels, supporting the diagnosis of insulin dysregulation.

Research Design and Methodology

• The study involved 22 Crioulo horses, split into three categories based on their body condition scores (BCS) and the presence or absence of laminitis; a condition affecting horses’ hooves. The groups were: CON (Control horses with BCS less than 7), OB (Obese horses with BCS greater than or equal to 7), and LAM (Obese horses with BCS greater than or equal to 7 and showed signs of laminitis).
• A thorough medical history was gathered including physical examination, morphometric measurements (physical dimensions of body), a radiographic examination of the front feet, and ultrasonographic measurements of subcutaneous body fat.
• The horses were subject to an Oral Sugar Test (OST) where the subjects were fasted overnight, followed by the initialization of the test. Blood samples were collected both before and after sugar administration.

Main Findings

• Significant differences (P < 0.05) were seen in the morphometric and metabolic measurements of the CON and obese groups, with the LAM group's horses displaying the highest body measurements and plasma insulin concentrations.
• A majority of the obese horses showed delayed peak glucose responses in the OST, indicating that glucose sampling between 60 to 90 minutes post-sugar ingestion – a method previously employed for hyperinsulinism detection – may be inappropriate.
• The delayed return to normal glucose levels, coupled with elevated insulin levels in the blood, was indicative of insulin dysregulation common in cases of equine metabolic syndrome (EMS).

Conclusions and Implications

• The observed variances in glucose and insulin responses to an OST in the obese Crioulo horses demonstrate clear obesity-related metabolic differences.
• This study’s findings suggest that the protocol for Oral Sugar Test (OST) in detecting EMS in Crioulo horses may need modification, given the delayed peak glucose response observed.
• These results carry great value as they can contribute to an early diagnosis of Equine Metabolic Syndrome (EMS) and prevention of related complications such as laminitis in obese Crioulo horses.