Which demographic is most affected by functional urethral outflow obstruction (FOO)?

Functional urethral outflow obstruction (FOO) primarily affects middle-aged, large, and giant breed male dogs due to several anatomical and physiological factors. In larger breeds, the prostate gland can become enlarged, leading to compression of the urethra. Additionally, male dogs are more prone to certain diseases and disorders, such as benign prostatic hyperplasia, which can impede the normal flow of urine.

The age factor plays a significant role because middle-aged dogs often experience a combination of age-related anatomical changes and health issues that predispose them to urethral obstruction. Furthermore, large and giant breeds may have a more significant risk due to their size, as the greater body mass can influence the structure and functioning of the urinary tract.

Other demographics, while they may possibly experience urethral problems, typically do not present the same level of risk for FOO as middle-aged, large, and giant breed male dogs.