Canine Bilateral Extraocular Polymyositis

• In Golden retrievers
• Very rare
• Clinical signs:
  • Acute bilateral exophthalmos
• Involves only extraocular muscles except for retractor blbi
• Grossly:
  • Swollen and pale extraocular muscles
• Histologically:
  • Sterile myositis
  • Multifocal necrosis of myofibres
  • Lymphocytic, histiocytic and plasmacytic infiltrate with few neutrophils