Morphometry of the male feline pelvic urethra.

The pelvic urethra and bladder of the male cat were examined for comparison with those of the male dog which have been previously studied. Morphometric data were generated and analyzed statistically to provide an objective basis for comparing regions and species. Tissue quantities in the body of the bladder were significantly different from the vesical neck. The vesical neck of the cat was significantly different from the canine vesical neck. The smooth muscle sphincter in the cat was better developed than in the dog, and the cat had longitudinal smooth muscle arranged to actively open the sphincter. The feline urethra had relatively more elastic fibers and less stratum cavernosum than the canine urethra. Since canine and feline urethrae are structurally different, physiological interpretations based on one of the species should not be applied indiscriminantly to the other.