Morphometric analysis of the foramen magnum in German Shepherd dogs (Alsatians)

Abstract

In this study, a total of 32 skulls from German Shepherd (Alsatian) puppies were used. These animals were divided into two groups and examined individually. Group 1 included the puppies of between 43-60 days old. Group 2 included the puppies of between 61-107 days old. We based our study on the changes in shape and size of the foramen magnum and the correlation of normal craniometric measurements in the German Shepherd puppies. In group 1, a maximum width of the foramen magnum of 15.55 mm, a height of the foramen magnum of 14.38 mm and a foramen magnum index of 92.67 were observed. In group 2, a maximum width of the foramen magnum of 17.49 mm, a height of the foramen magnum of 16.34 mm and a foramen magnum index of 93.51 were measured. A high positive correlation was found between the maximum width and height of the foramen magnum, the maximum width of the occipital condyles, the maximum width of the bases of the jugular processes, the skull height, the height of the occipital triangle, the skull length from prosthion to basion and the skull length from prosthion to the caudal borders of the occipital condyles. A negative correlation was observed between the width and height of the foramen magnum and indices. Although there was no relation between the foramen magnum index and the age of the animals, an important difference was found between groups 1 and 2. A negative correlation was observed between the foramen magnum index and the rate of increase in the cranial volume. In all the animals examined, the dorsal bone of the foramen magnum was closed, therefore any extension or dorsal notch was not seen. Such an extension or dorsal notch of the foramen magnum in the German Shepherd puppies may therefore be the result of a pathological condition.