Phimosis and Paraphimosis are two conditions that involve penis and its ability to retract or protrude the prepuce (foreskin). Inability of a dog to protrude its penis from its outer orifice is called phimosis while paraphimosis refers to the inability of a dog to retract its penis into the sheath.
Phimosis is a reproductive problem that occurs when the opening in a dog's prepuce, the skin sheath over his penis, is not large enough. Dogs with phimosis often can't mate because the penis can't protrude from the skin.
Paraphimosis is a condition that causes the inability of a dog's distended penis to retract properly, such as during the mating process. This may appear to be an extended erection, or the flaccid penis may not slide properly back into the sheath.
Phimosis or paraphimosis can occur in male dogs of any age. The causes of each of these disorders are different.
Paraphimosis may go unnoticed until the dog is involved in mating process. Difficulty in urinating is also a sign of this medical disorder. Phimosis is noticed when the dog is seen excessively licking exterior of its penis which can result in fluid accumulation or swelling in the area.