Callus

• Hypertrophy of epidermis, particularly at pressure points
• Usually affects giant breed dogs and pigs kept on hard floor
• May be followed by folliculitis, furunculosis and ulceration
• Microscopically:
  • Hyperkeratosis and acanthosis or epidermis and follicular epithelium
  • Comedones and follicular cysts may be present, potentially rupture and cause secondary pyoderma
  • Excessive keratin widening follicular openings