- Congenital or acquired conformational abnormality in foals a few weeks to several months old.
- Carpal valgus, fetlock varus most common.
- Limb deviates in a frontal (medial-lateral) plane distal to a joint where there is some abnormality of growth.
- All breeds, no sex prediliction - although high incidence reported in Quarterhorses .
- May be single or multiple joints affected.
- Carpal valgus accounts for approximately half all cases; fetlock varus for 45%, followed by carpal varus and other types, eg tarsal valgus.
- Cause : multifactorial etiology resulting in asymmetric joint pressures and growth imbalance at physis, eg dysplasia, fetal malposition, premature birth, ligament laxity, incomplete ossification of carpal/tarsal bones, trauma, sepsis, favoring of limb.
- [Musculoskeletal: conformation] , may be lameness [Musculoskeletal: gait evaluation] , abnormal posture. (Figs. 1-2)
- Diagnosis : physical examination , radiology [Forelimb: radiography] [Hindlimb: radiography] .
- Treatment : tailor to individual; medical - manual reduction, confinement, cast [Musculoskeletal: external fixation - casts] , diet management [Nutrition: growth] , or surgical - transphyseal bridging [Carpus: growth retardation - angular deformity] , hemicircumferential periosteal transection [Carpus: growth acceleration - angular deformity] , corrective osteotomy.
- Prognosis : good - depends on cause, severity and age at treatment.
Print off the Owner factsheet on Flexural limb deformities to give you your client.
- Conformational deformity:
- Lameness [Musculoskeletal: gait evaluation] .
- Local heat and swelling.
- Manual reduction:
- Apply pressure to medial side of carpus/tarsus.
- Apply counter pressure to lateral aspect of distal limb simultaneously.
- Temporary correction → (suggests periarticular laxity, and amenity to conservative management).
- Good; for reducible and deformities <20° up to 6 months of age.
- Fair; for severe deformities >20° and <12 months old.
- Guarded; for some severe deformites in older foals and those >12 months old.