Coloboma

From Cow
Typical coloboma found in a young calf[1]

Coloboma usually refers to defects in the bovine iris, but can also apply to defects within the lens or retina[2].

This eye disorder is relatively rare autosomal dominant genetic disease with complete penetrance in bulls and partial penetrance in cows.

It is primarily observed in Charolais breeds[3].

The disease has also been associated with other congenital defects such as hydrocephalus[4].

There is no specific treatment for this disease and affected cattle with only one affected eye may be salvaged but should be removed from the breeding herd[5].

References

  1. Martin, CL (2009) Ophthalmic Disease in Veterinary Medicine, p:413
  2. Falco M & Barnett KC (1978) The inheritance of ocular colobomata in Charolais cattle. Vet Rec 102(5):102-104
  3. Wijeratne WV & Curnow RN (1978) Inheritance of ocular coloboma in Charolais. Vet Rec 102(23):513
  4. Greene HJ et al (1974) Bovine congenital defects: variations of internal hydrocephalus. Cornell Vet 64(4):596-616
  5. McCormack J (1977) Typical colobomas in Charolais bulls. Vet Med Small Anim Clin 72(10):1626-1628