Plasma and tissue histamine in equine grass sickness.

The research studies the levels of histamine in equine grass sickness, a fatal disease in young horses. The study aims to see if there is a possible relationship between increased histamine release and this sickness, as histamine is known to be released in response to immune reactions and ailments that are common symptoms of the disease.

Objective and Background

• The primary aim of the research is to explore the possibility of increased histamine release in horse grass sickness, a fatal disease primarily affecting young horses. The disease manifests clinical signs such as severe stress, tachycardia, bowel stasis, vomit, and hypersecretion of the upper bowel. The severity and duration of the disease can vary.
• Despite the severe symptoms, the causes behind the enteric and autonomic nervous lesions in grass sickness remain unclear. The research brings into consideration the immune mechanisms which cause similar lesions in Chagas’ disease, as well as factors such as food allergies and acute equine anaphylaxis known to result in histamine release.

Histamine and its Relevance

• Histamine is released as a result of immune responses and is prevalent in stress, gastric ulceration, and hypersecretory states. It is also present in cardiovascular disorders such as circulatory shock and pulmonary hypertension. Therefore, the notion of increased histamine release possibly occurring in equine grass sickness piqued the researchers’ interest. This set the stage for conducting scientific tests on the same.

Analytical Approach and Methodology

• The researchers took plasma and tissue from two areas (ileum, coeliaco-mesenteric ganglia) marked by maximum pathology in peracute, acute, early subacute, and chronic grass sickness in horses. Histamine concentrations were studied by a specific radio-enzymatic assay. Comparisons were made with histamine levels in healthy horses.
• The plasma histamine level was determined from jugular blood samples previously measured for plasma stress hormone concentrations. The statistical differences in various groups and variables were analysed and recorded.

Scope of the Research

• By investigating the relation between equine grass sickness and histamine release, the researchers hope to provide new insights into the disease’s causes and develop strategies for treatment and prevention.