Hepatozoon

• Tick borne disease
• Two species:
  • Hepatozoon canis
    • Usually subclinical disease
  • Hepatozoon americanum
    • SE USA
    • Grossly:
      • Thickened and edematous periskeletal soft tissue and periosteum of the lower legs
      • Multifocal parasitic myositis
    • Histologically:
      • Swelling and hypertrophy of osteoprogenitor cells
      • Hyperplasia of spindle cells
      • Osteoid is produced
• More detail on Hepatozoon americanum
• Myositis
  • Develop cysts in skeletal muscle of dogs and cats
  • May be accompanied by pyogranulomatous myositis - macrophages and neutrophils mainly with occasional other cells