Windgalls

Chambers's Encyclopaedia, Volume 10: Swastika to Zyrianovsk and Index, p. 679

Windgalls are puffy swellings about the fetlock-joints of animals, particularly of horses, resulting from an increased secretion of synovia arising from work, particularly on hard roads: they are generally unassociated with any pain, heat, or lameness, and are not generally considered to be causes of unsoundness. If the horse be young they may disappear if the animal be allowed a long rest and the parts blistered once or twice. Old horses having windgalls are generally kept at work, the legs being bandaged when in the stable.

Source scan(s): p. 0708