Authors: Paraschou Georgios, Cook Joanna M, Priestnall Simon L, Evans Nicholas J, Staton Gareth J, Paterson Gavin K, Winkler Betina, Whitbread Trevor J
Journal: Veterinary pathology
Summary
# Editorial Summary: Treponemes and Fungi Identified in Donkey Keratomas Keratomas—benign keratin masses lodged between the hoof wall and third phalanx—remain poorly understood lesions in donkeys, though they're typically associated with chronic irritation, infection, or trauma. Researchers examined 167 affected donkeys using clinical assessment, radiography, and detailed histopathology with special stains, performing targeted PCR testing for treponeme bacteria and fungal pathogens on affected tissue and healthy controls. Digital dermatitis treponeme phylogroups were identified in 30% of keratoma samples but in none of the healthy tissue controls, whilst keratinopathogenic fungi—those capable of degrading keratin—appeared in 12.5% of lesions against only environmental, non-pathogenic fungi in controls. These findings represent the first documented association between keratomas and both DD treponemes and keratinopathogenic fungi, suggesting these microorganisms may play a role in keratoma formation or progression rather than being merely incidental. Practitioners should recognise that keratomas may have an infectious component warranting further investigation; whilst the clinical significance requires confirmation through additional research, this opens consideration of whether antimicrobial or antifungal strategies might complement surgical management, particularly in cases with recurrence or incomplete resolution.
Read the full abstract on PubMed
Practical Takeaways
- •Keratomas in donkeys may involve infectious agents (treponemes and fungi) previously associated with digital dermatitis, suggesting potential shared pathogenic mechanisms worth investigating further
- •Surgical excision remains the treatment approach for lame donkeys with keratomas, though understanding the infectious component may inform prevention or post-operative management strategies
- •Consider infectious disease protocols when managing keratomas, particularly in herds with history of digital dermatitis, pending further research on causative significance
Key Findings
- •Digital dermatitis treponeme phylogroups detected in 30% (3/10) of keratoma samples but 0% of healthy control hoof tissue
- •Keratinopathogenic fungi identified in 12.5% (1/8) of keratomas versus only non-pathogenic environmental fungi in control samples
- •Histopathological examination revealed fungal hyphae and spirochete bacteria present within degenerate keratin of keratomas
- •First documented evidence of DD treponemes and keratinopathogenic fungi association with keratomas in 167 donkeys