Protein profiles of whole homogenates of anconeus (slow twitch) and biceps femoris (fast twitch) muscles of clinically normal dogs and of Labrador Retrievers with hereditary myopathy (HM) were resolved on flat bed polyacrylamide isoelectric-focusing gels. Three methods of sample solubilization were performed. The solubilization buffer, with high concentrations of urea, precipitated the zwitterionic detergent, but use of the buffer containing 3% NP-40, 9.2M urea, and 0.1M arginine resulted in better resolution and stability of pH gradient. Gels of anconeus muscle from clinically normal dogs contained 2 protein bands specific to anconeus muscle, whereas gels of biceps femoris muscle from clinically normal dogs contained 3 protein bands amplified in biceps femoris muscle that were barely detectable in anconeus muscle. The staining intensity of protein bands in biceps femoris muscles from Labrador Retrievers with HM was decreased, relative to controls. The quantitative analysis of peak height ratios of biceps femoris muscle revealed significant (P less than 0.05) differences between profiles of clinically normal dogs and Labrador Retrievers with HM.

Between January and april, 1992, two captive Bennett's wallabies (Macropus rufogriseus) from a wildlife park in Iwamizawa City, Hokkaido, Japan, were diagnosed as having nutritional myopathy. One wallaby, four-year-old adult male, had mild fresh lesions, confined to the skeletal muscles, with poor cell reaction. The other wallaby, 8-month-old female joey, had marked and extensive lesions with cellular reactions and regenerative muscle fibers in the locomotor muscles. Involvement of other striated muscles such as those of the tongue, diaphragm and heart was mild with minimal cellular reaction. Age susceptibility may account for the difference in the extent of severity of the lesions between these two animals

An ultrastructural study was to investigate on 2 cases of canine leiomyosarcoma. The nuclei of most tumor cells showed bilobate appearance. Most cells of the tumors had no distinct basement membrane. Most cells of the tumors had a degenerative rough endoplasmic reticulum. Intercellular matrix contained some amounts of collagen. Attachment areas between tumor cells were not apparent, but a few tight junction were clearly seen. Myofibrils were present in bipolar end area