Arabians, pure and part-bred
Friesians, pure and part-bred
Warmbloods, pure and part-bred
Fell Ponies, Dale Ponies and Gypsy horses, pure and part-bred
Quarter horses and related breeds, pure and part-bred
Saddlebred and related breeds, pure and part-bred
Akhal Teke, pure and part-bred
Connemara, pure and part-bred
Coat colour tests
Hoof wall separation disease (HWSD) is an inherited disorder that has been found in Connemara ponies. In ponies affected by HWSD the hoof wall separates from the internal structures of the foot and breaks. Without a strong hoof wall, the weight of the pony goes disproportionately through the sole of the foot. This can cause lameness. Signs of HWSD are not present at birth but usually start at less than six months of age.
HWSD is an autosomal recessive disorder. Autosomal disorders are equally likely to affect male or female horses, while "recessive" means that a horse needs to inherit the HWSD mutation from both its sire and its dam to be affected. Horses that have inherited the HWSD mutation from just one parent are called HWSD carriers, and do not have physical signs of this disorder.
Our information and terminology is based on the sequences and content in Finno et al., 2017, describing a single nucleotide insertion in the SERPINB11 gene.
HWSD affects all four feet. In affected ponies the hoof wall separates easily from the underlying structures of the foot.