Morphometry of the female feline urethra

Tissues composing the lower urinary tract of the female cat were described and analyzed morphometrically. Statistical comparisons were made with the female dog using previously obtained canine morphometric data. Despite a superficial similarity, the cat differs from the dog in having a significant component of longitudinally oriented urethral smooth muscle and appreciably less striated urethral sphincter. It is suggested that the cat requires an active mechanism for overcoming continence due to an inherently smaller urethral lumen, compared to the dog. The implication of our morphometric findings is that urethral mechanics are different for the female cat and dog.