What is a cleft palate?? A cleft palate is an opening between the mouth and the nose that happens when the tissues separating these two cavities do not grow together properly. The defect results are in direct communication between the mouth and nasal cavity. It is one of the most common congenital defects seen in puppies and kittens. It occurs during embryonic development and is considered a congenital malformation, which means it is present at birth. During pregnancy certain drug, deficiency in