Search

Previous studies have described the paw preference and asymmetry in dog brains, based on experimental studies. The purpose of the present study is to investigate a possible association between callosal anatomy and paw preference in dogs. The midsagittal area of the dog corpus callosum was measured in its entirety and in six subdivisions in a sample of 21 brains obtained from 9 male and 12 female mongrel dogs which had paw preference testing. The present study showed significant paw differences in dog corpus callosum. A posterior segment of the callosum, the isthmus, was significantly larger in the right pawedness than the left.

Human studies reported sex differences in size and shape of the corpus callosum. These observations have been contested. The purpose of the present study is to investigate possible sex differences in the corpus callosum of dogs. The entire brains including the medulla from 12 female and 9 male adult mongrel dogs were removed and weighed. Total and partial area measurements of the callosum were made from photographic tracings of its outline. The callosum was partitioned into 3 regions; anterior half, posterior half, posterior one-fifth. The total corpus callosum, anterior half, posterior half, and posterior fifth or splenium areas were measured. Sex differences were found. The anterior half, the posterior half, the posterior fifth, and the total callosum were significantly greater in absolute area in males than in females.