Congenital tarsal hyperextension in three cats

3 kittens were examined because of a malformation affecting the hind limbs, resulting in an inability to bear weight or ambulate normally.

2 kittens were younger than 6 weeks of age, and 1 was 4 months of age at the time of initial examination. The congenital abnormality was characterized by severe tarsal hyperextension in which weight was borne on the cranial aspect of the tarsus, and the plantar surface of the metatarsus faced dorsally. In 2 kittens, the condition affected both hind limbs, and in the older kitten, the condition was unilateral. In the 2 kittens in which radiographs were obtained, no bone abnormalities were detected. Full-cylinder fiberglass casts were applied and changed weekly to accommodate growth. Owners administered physical therapy after final cast removal.

Conservative management involving external coaptation and physical therapy led to favorable results in all 3 cats.

Although further studies are needed to determine the etiology of the disorder, affected kittens may be successfully treated with conservative management. Owners should be committed to the necessity for returning cats for serial cast changes, care for pressure sores, and administration of physical therapy after cast removal.