A quantitative study on the trachea of the dog

Area of Science:

• Veterinary Anatomy
• Comparative Morphology

Background:

• The canine trachea's detailed morphometric structure is crucial for understanding respiratory function and potential pathologies.
• Previous studies have provided general descriptions, but regional variations and their clinical implications require further investigation.

Purpose of the Study:

• To conduct a detailed morphometric analysis of the canine trachea.
• To identify regional variations in tracheal ring dimensions and shape.
• To assess the risk of tracheal collapse based on morphometric characteristics.

Main Methods:

• Morphometric measurements of tracheal ring diameter and thickness were performed on 19 healthy adult mongrel dogs (15 female, 4 male).
• Data were statistically analyzed across four distinct tracheal regions: cranial cervical, middle cervical, thoracic inlet, and intrathoracic.
• Tracheal ring fusion and cross-sectional lumen areas were also evaluated.

Main Results:

• The number of tracheal rings ranged from 36 to 45.
• Tracheal ring diameter and thickness were smallest at the thoracic inlet.
• The trachea exhibits a near-circular shape, with ratios of transverse to vertical diameters between 1.14 and 1.25.
• Cross-sectional lumen areas were smaller at the thoracic inlet compared to other regions.
• Tracheal ring fusion was noted in the cranial cervical and thoracic inlet regions.

Conclusions:

• The canine trachea's morphometry varies significantly by region, with the thoracic inlet being a critical area.
• The reduced diameter, thinnest cartilage, and smaller lumen at the thoracic inlet increase the risk of tracheal collapse.
• These findings provide valuable data for veterinary diagnostics and surgical interventions involving the canine trachea.