Bog spavin

Veterinary advice should be sought before applying any treatment or vaccine.

Bog Spavin

Serous Tarsitis

Bog spavin is a soft, fluid-filled swelling in the hock appears on the inside front or sides of the hock joint. It is caused by excess synovial fluid and/or thickened synovial tissue. The swelling usually fills in the natural depression on the front face of the horse's hock. The presence of the swelling does not cause lameness in affected horses. However regardless of the degree of lameness, the presence of bog spavin should be evaluated by a veterinarian.


Soft, fluid-filled swelling on the inside and front of the hock


  • History
  • Clinical signs
  • Physical exam
  • Radiographs
  • Ultrasound

While waiting for your veterinarian

  • Supportive care: Cold hosing and rest


Determine the underlying cause: Radiograph images and/or ultrasound

Scientific Research References

Good Overviews

  • bog spavin icon

Risk Factors

  • Poor conformation : Horses with post legs and/or sickle hocks.
  • History of recent trauma or stall rest.
  • Working horses on hard surfaces.