Proposal for a new radiological index to determine skull conformation in the dog.

Measurements of the canine skull are of main interest in brachycephalic dogs. They are suspected to have diseases associated with the shortened nose, which are summarized under the term brachycephalic syndrome. The relative length of the nose has become an important feature in breeding and research, although a definitive correlation to the brachycephalic syndrome still has not been proven (Knecht, 1979; Harvey, 1982; Aron und Crowe, 1985; Koch et al., 2003). Classifications of skull types can be made by two methods. The traditional phenotypic assignment into brachycephalic, mesaticephalic and dolichocephalic is based on the assumption, that dogs of a specific breed have more or less uniform skull shapes. However, alterations due to breeding and differences between individual dogs of the same breed must lead to modifications. Therefore and for a more subtle classification, skull measurements were introduced (Brehm et al., 1985; Evans, 1993; Regodon et al., 1993),