Cytological and bacteriological evaluation of transendoscopic guttural pouch lavages in clinically healthy horses.

This study investigates the cellular and bacterial contents of guttural pouch lavages in healthy horses, finding that these lavages typically contain limited neutrophils and mainly transient microflora.

Research Overview

The research involved evaluating the cytological (cellular) and bacteriological (bacterial) contents of guttural pouch lavages. These lavages or wash samples were collected from 19 clinically healthy horses. Both cytological and bacteriological examinations of the samples were performed to gain better understanding of what constitutes a ‘normal’ guttural pouch environment in healthy horses.

Cytological Examination

• The cytological examination focused on assessing the types and number of cells present.
• Out of all the lavages examined, each contained less than five per cent of neutrophils, a type of white blood cell. According to cytological parameters, these can be referred to as ‘normal’.
• There were no lavages where the neutrophil count fell between five and 25 per cent or exceeded 25 per cent. These values are considered as benchmark for ‘reactive’ or ‘pathological’ conditions, respectively.
• The most commonly observed cells in all wash samples were epithelial cells.

Bacteriological Examination

• The bacteriological culture was positive in 16 out of 38 lavages, indicating the presence of bacteria.
• Despite the presence of bacteria, none of the lavages showed any specific pathogenic (disease-causing) bacteria. Only transient microflora, or temporary bacterial inhabitants were present.

Implications of the Study

• Despite the researchers’ inability to statistically assure the relationship between specific bacteria, neutrophil count, and total cell count (due to absence of ‘reactive’ and ‘pathological’ lavages), the study paints a provisional picture of a ‘healthy’ guttural pouch environment in horses.
• The overall findings suggest that the transendoscopic lavage method is reliable for gathering sample for bacteriological culture from the guttural pouch.