A review of cytological specimens from horses with and without clinical signs of respiratory disease.

The research article discusses how the examination of cytological specimens from horses, collected via transtracheal washing and bronchoalveolar lavage, aids in diagnosing and understanding different respiratory diseases. This approach showed practicality, with minimal complications, and it revealed respiratory issues in some horses that did not show identifiable clinical signs.

Study Design and Samples

• The research included 36 transtracheal washing (TTW) and 12 bronchoalveolar lavage (BAL) specimens from horses both with and without signs of respiratory disease.
• These samples were collected in a clinical setting and studied for their cytological features.

Cytological Interpretation & Link with Current Findings

• The cytological features observed were considered in light of various factors such as the presenting complaint, clinical signs, diagnosed conditions, microbiological, radiographic, and endoscopic findings, treatment, and the horse’s response to the said treatment.
• The cytological analysis of these trichrome-stained TTW and BAL specimens was beneficial in interpreting the results of concurrent microbiological cultures, thereby aiding in the diagnosis of the medical condition under consideration.

Role of Cytology in Diagnosis and Identification of Aetiologies

• Cytology could identify various conditions from typical cytological patterns, which included probable allergy, chronic obstruction, exercise-induced pulmonary haemorrhage, etc.
• It was also effective in determining pathological or anatomical diagnoses, such as bronchitis, bronchiolitis, alveolitis, presence of metaplasia or dysplasia and possible causes, including allergy and bacterial infections.

Practicality and Importance of Cytological Evaluation

• The study highlighted the practical use of cytological specimens in assessing the equine respiratory tract, with minimal unsatisfactory samples and no reported complications.
• Cytology’s importance in respiratory assessments was accentuated by its ability to identify 13 cases where respiratory issues were present despite the absence of any physical examination signs.

Long-Term Cytological Tracking

• The authors suggest sequential collections of cytological samples from foals, young horses before and during early training, and mature horses in training.
• This sequential tracking may provide more information about the lung’s response to stressors associated with training and common environmental exposures.