Histological differences between brachycephalic and normocephalic dog palatine tonsils

Area of Science:

• Veterinary Pathology
• Comparative Anatomy
• Canine BOAS Research

Background:

• Brachycephalic Obstructive Airway Syndrome (BOAS) is common in certain dog breeds.
• Palatine tonsil abnormalities may contribute to BOAS.
• Histological comparison of tonsils between brachycephalic and normocephalic dogs is lacking.

Purpose of the Study:

• To compare the histological morphology of palatine tonsils from brachycephalic and normocephalic dogs.
• To identify pathological differences in tonsils associated with BOAS.
• To evaluate the potential role of tonsillectomy in BOAS treatment.

Main Methods:

• Histological examination of palatine tonsils from 116 dogs with BOAS and 11 normocephalic controls.
• Standard histological techniques and digital microscopy were employed.
• Measurements of tonsillar epithelium and lymphoid follicles were compared between groups.

Main Results:

• Brachycephalic tonsils showed significantly greater epithelial width (48% thicker) and lymphoid follicle area (52% larger) compared to controls.
• Neutrophilic inflammation within the epithelium was present in 54% of brachycephalic tonsils but absent in controls.
• These findings indicate significant histopathological differences in tonsils of dogs with BOAS.

Conclusions:

• Brachycephalic palatine tonsils exhibit lymphoid and epithelial hyperplasia, and neutrophilic inflammation.
• These changes are likely secondary to airway irritation from BOAS.
• Surgical correction of BOAS may resolve tonsil abnormalities, potentially making tonsillectomy unnecessary, warranting further research.