Stress response as a contributing factor in horses with laminitis

Area of Science:

• Equine medicine
• Veterinary endocrinology
• Animal physiology

Background:

• Laminitis is a complex equine disease with undetermined pathogenesis.
• The role of stress hormones like T4, cortisol, and histamine in laminitis is largely unknown.
• Understanding stress markers may elucidate laminitis development.

Purpose of the Study:

• To investigate stress response parameters in horses with laminitis.
• To compare stress markers in laminitic horses with those in horses with gastrointestinal disease and healthy controls.
• To evaluate plasma histamine, endogenous adrenocorticotrophic hormone (eACTH), serum cortisol, and serum T4 concentrations.

Main Methods:

• Prospective enrollment of 38 adult horses into healthy, GI disease, or laminitis groups.
• Blood samples collected on hospital presentation for analysis.
• Quantification of plasma eACTH, serum cortisol, serum T4, and plasma histamine.

Main Results:

• Plasma histamine was highest in laminitis cases compared to GI disease and controls.
• Both laminitis and GI disease groups showed increased plasma eACTH versus healthy horses.
• GI disease horses had higher serum cortisol and lower serum T4 than laminitis or control horses.

Conclusions:

• Horses with laminitis exhibit elevated plasma histamine and eACTH.
• Serum T4 and cortisol levels in laminitic horses were not significantly different from healthy controls.
• Further research is needed to clarify the role of stress hormones in equine diseases.