Cutaneous Habronemiasis

• In horses (also calles summer sores)
• Caused by Habronema sp. or Draschia sp. - spread by house flies or stable flies
• In traumatised or moist soft skin
• Grossly:
  • Single or multiple tomorous masses that proliferate and ulcerate
  • Red to brown, on section have small gritty yellow to white foci
• Microscopically:
  • Nodular dermatitis
  • Eosinophils, epithelioid macrophages, multinucleated giant cells
  • Larvae and necrotic tissue
  • Granulation tissue with neutrophils along ulcerated surface