Patients with urinary obstruction are most often male and neutered. In male rats and rabbits, androgen depletion appears to result in changes to penile structures. This study examined the extracellular matrix in the penises of neutered male cats as compared with intact male cats. Results showed neutered male cats to have an increased density of fibers in the corpus spongiosum and decreased density of elastic fibers as compared with intact male cats, suggesting decreased compliance of the periurethral region that may increase risk for obstruction in neutered male cats.