Pain Assessment in Horses — Advances in Behavioral Science

Horse pain assessment has advanced dramatically with the development of validated behavioral scales, improving veterinary care and welfare for these large, stoic animals.

Key Facts

The Horse Grimace Scale (HGS) uses facial muscle contraction to assess acute pain in horses
Equine pain signs include pawing, flank watching, and altered facial expression — all quantifiable
Lameness — a sign of musculoskeletal pain — affects an estimated 1 in 10 horses in the UK at any time
Dental pain in horses is severely undertreated because horses rarely show obvious distress
The Obel scale provides standardized grading for laminitis pain — a common and severe equine condition

Welfare Considerations

Horse pain assessment has been transformed by behavioral pain science over the past decade. Validated scales including the Horse Grimace Scale allow owners and veterinarians to recognize and quantify pain that horses — prey animals that hide weakness — would otherwise mask. Laminitis causes excruciating pain that horses suppress through behavioral changes rather than vocalizations. Dental pain, which is extremely common in older horses, causes head-tossing and reduced food intake that owners may attribute to temperament rather than pain. Applying validated pain scales routinely rather than only in acute situations dramatically improves chronic pain detection and treatment.

What You Can Do

Learn the Horse Grimace Scale and apply it to assess your horse's acute pain responses
Schedule annual dental checks with an equine dentist for all horses over 5 years old
Advocate for lameness evaluation to be routine in equine welfare assessments
Support research into chronic pain detection and management in equine practice
Report signs of unmanaged horse pain to equine welfare organizations