Pathological changes were limited to myofiber hypertrophy in cats with myotonia congenita.

a. H&E stained cryosections of the biceps femoris muscle. Hypertrophy involved both type 1 and type 2 fibers. b. H&E stain of biceps femoris muscle. c. Antibody staining for type 1 (brown color) and type 2 (red color) fibers. For comparison of fiber size, an unaffected approximately age matched control cat muscle is shown. b. H&E stain of biceps femoris muscle; d; antibody staining for type 1 and type 2 fibers. Magnification bar  = 100 µm for all images.