Angular Limb Deformities in Foals

Normal Foals
Foals are born with soft “slipper-like” almost gelatinous hooves. However, within a few hours their feet have hardened. In foals with correct limb conformation there is little need for major interference with the feet. However it is common practice for good studs to call upon a farrier to assess and dress foals feet on a regular basis. The first contact, in normal circumstances, is at four weeks. By this time, mild angular deviations and other limb abnormalities of newborn foals, such as fetlock hyperextension as a result of flexor tendon laxity, will usually have improved. The hooves will require trimming before becoming overgrown and training can begin while the foal is small and receptive.
The conformation and hoof shape should be constantly monitored throughout development.
Usually foals require foot trimming every four weeks. Even foals which are considered “perfect” have slight deviations. Deviations are categorised into two types; “valgus” describes the deformity when the limb distal to the point of deformity is lateral to the proximo/distal axis of the limb, and “varus” when it deviates medial to that axis.
It is normal for newborn foals to have a slight (5o) carpal valgal conformation. This distorts foot growth by pushing the hoof capsule laterally and shunting the medial bulb of the heel proximally. The medial hoof wall may also wear more than the lateral side. Trimming is designed to restore normal foot balance by correcting such distortions.
A foal's foot does not only grow in the manner of a mature horse, in a distal direction, it is also expands. Since most expansion occurs proximally, most foal hooves are tapered. As the distal hoof is a relatively small, the weight-bearing area is positioned dorsally. Correct trimming will enlarge this area and move it in a palmar/plantar direction. The feet of foals of one to two months of age have a pointed shape. Trimming should encourage a more round or even square foot shape, to promote even break-over.
Normal foals have a slight valgal conformation of their forelimbs, which is usually less than five degrees. As the foal grows and its chest broadens, such a mild deformity ends up with correct limb conformation.  [...]