A rare and interesting surgical case – Polydactyly Foal
A 7-week-old filly cob foal presented to Lower House Equine Clinic for surgery of an extremely rare condition – polydactyly. This is where an extra ‘digit’ forms as the foal develops as a foetus within the uterus.
X-Rays were taken first of all to determine from where the extra digit started from. The -rays showed that the digit originated from the carpus (knee). The foal’s inside splint bone (second metacarpal bone) had fully developed into an equine digit, containing all of the structures normally visible on an equine x-ray: cannon bone, proximal sesamoid bones, fetlock joint, pastern joint, pastern bones, pedal bone and navicular bone.
Surgery was carried out under general anaesthetic to remove the extra digit. Simon had to cut the second metacarpal bone (new cannon bone) and then separate all of the structures away. During the surgery he found that the new digit had all of the normal structures found in the equine digit, including superficial digital flexor tendon, deep digital flexor tendon, suspensory ligament, tendon sheath, manica flexoria, all associated joints, and all blood vessels and nerves. It was a complicated surgery to separate out all of these structures and leave the correct structures in place for the foal’s remaining functional limb.
Once surgery had been performed, the skin was stitched up and a bandage was placed on the leg.
The foal has since returned home, the wound has healed, and it is living a normal life in the field with its mum.