Geometric morphometric analysis of scapula at cats and dogs

Abstract

The scapula in quadrupedal mammals is a flat bone that connects the thoracic limb with the trunk above the shoulder joint. For this purpose, scapulae of 34 dogs and 23 cats were modeled using computer tomography. 9 Landmarks and 50 semilandmarks were used. The cat and dog samples differ in scapula shape, as do male and female cats. Centroid size has no apparent covariance with shape, and we did not find any difference between the two sexes in dogs. The scapula of cats was wider. The scapula of dogs was narrower and longer. Margo cranialis was more oval in cats. Angulus cranialis border was not clear in cats. Angulus caudalis was sharper in dogs. Spina scapulae was closer to caudal in cats. In cats, the fossa supraspinata was wider than the fossa infraspinata. Also, the collum scapulae was narrower in cats. The scapula of male cats was wider than that of female cats. In shape, the fossa supraspinata was wider in male cats. In male cats, the spina scapulae were more caudal. Angulus caudalis was wider in female cats. The most significant gender differences in dogs were in tuberculum supraglenoidale and margo caudalis. Male dogs had larger tuberculum supraglenoidale in shape. Margo caudalis was more caudal in male dogs. Geometric morphometrics was found to be effective in distinguishing the scapula of cats and dogs. In addition, this method can be useful in sex estimation.

Keywords

• cat
• dog
• geometric morphometrics
• principal component analysis
• scapula
• sex differentiation
• taxonomy