When male dogs are breeding age is it normal for their stuff to hang out all the time?

It is somewhat normal for a male dog to have his penis extended slightly beyond the prepuce as opposed to being totally concealed within the sheath when they are sexually mature, but it should not protrude a substantial amount. If it does, it could indicate a medical condition known as paraphimosis, which occurs when the penis becomes stuck outside of the prepuce and can not be retracted. Paraphimosis can cause tissue injury, pain, and even infection. If your dog's penis is extended continuously for more than a few minutes, it is best to consult a veterinarian for examination and treatment recommendations.