A numerical classification system for cleft lip and palate in the dog.

An easy-to-use classification that enables an accurate record of canine cleft lip and palate is fundamental for effective communication between professionals and researchers and optimal use of published information. Here we present how a classification system for human cleft lip and palate can be used to register spontaneous cases in dogs, highlighting its advantages. This system is based on four topographic areas with a numerical representation of the severity of the cleft in each area. The use of spontaneous cases has the advantage of providing clefts that are naturally similar to their human counterparts for surgical, genetic and genomic studies and, furthermore, will reduce the need for experimental models of this condition.