Cleft Lip

Definition: A failure of midline fusion during fetal development can lead to defects that affect different parts of the skeleton.

Clinical features: Two obvious cranial abnormalities are illustrated here. A cleft lip in a young Shorthorn calf is shown in 1.1, in which a deep groove extends obliquely across the upper lip, nasolabial plate and jaw, involving not only skin but also bone (maxilla). This calf had extreme difficulty in sucking milk from the dam without considerable loss through regurgitation.

Cleft palate is seen as a congenital fissure of varying width in both the hard and soft palates of neonatal calves (1.2). The nasal turbinates (A) can be clearly seen through the fissure. The major presenting sign is nasal regurgitation. An aspiration pneumonia often develops early in life from inhalation of milk, sometimes while still nursing. Some calves with smaller fissures may appear clinically normal during suckling because the teat when in the calf’s mouth, closes the fissure. Clinical signs are seen when it starts to eat solid food. Cleft palate is often associated with other congenital defects, particularly arthrogryposis. Other midline defects include spina bifida and ventricular septal defect.