Evaluation of bronchoalveolar lavage fluid from donkeys using four different cytological stains: A pilot study.
Authors: Vitale V, Bindi F, Briganti A, Bonelli F, Parietti C, Sgorbini M
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: BALF Cytology Staining Methods in Donkeys Bronchoalveolar lavage fluid (BALF) cytology is essential for diagnosing non-infectious lower airway disease in equids, yet clinicians have long recognised that different staining techniques can produce variable cell counts—a problem well-documented in human medicine and equine practice. Vitale and colleagues evaluated four common staining methods (modified May-Grunwald Giemsa, Diff-Quick, Toluidine blue, and Perls Prussian blue) on BALF samples from nine healthy Amiata donkeys to determine which provided the most reliable differential cytology. Modified May-Grunwald Giemsa (mMGG) and Diff-Quick showed equivalent results for macrophages, neutrophils and eosinophils, though Diff-Quick significantly undercounted mast cells compared with Toluidine blue—a clinically important distinction since mast cell elevation may indicate allergic airway inflammation. The authors concluded that modified May-Grunwald Giemsa offers superior identification of all cell types, particularly mast cells, and recommend against relying solely on Diff-Quick staining when accurate mast cell quantification is diagnostically necessary. These findings align with existing equine literature and suggest that standardising staining methodology across donkey respiratory investigations could improve consistency and reliability of BALF interpretation in clinical practice.
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Practical Takeaways
- •Use modified May-Grunwald Giemsa staining as the gold standard for donkey BALF analysis if accurate mast cell identification is clinically important for your diagnosis
- •If relying on Diff-Quick staining alone, be aware of potential mast cell miscounting and consider confirmation with alternative staining methods when mast cells are clinically significant
- •Results from this donkey study align with equine literature, suggesting similar staining considerations may apply across equid species
Key Findings
- •Modified May-Grunwald Giemsa (mMGG) and Diff-Quick (DQ) showed no significant differences in macrophage, neutrophil, and eosinophil counts in donkey BALF
- •Mast cell identification differed significantly between Diff-Quick and Toluidine blue stains, but not between mMGG and either method
- •mMGG stain demonstrated superior identification of all cell types including mast cells compared to other methods
- •Diff-Quick used alone may result in inappropriate mast cell identification in donkey BALF cytology