Anal atresia is a congenital anorectal deformity in dogs. It may occur by itself or in combination with other conditions such as hypospadias, an anomaly in which the urethra opens in an abnormal anatomic location.

The objective of this work is to present an uncommon case of simultaneous type II atresia ani, rectogenital fistula, penile hypospadias and agenesis of tail in a dog.

Eight-week-old male Dachshund was brought for revision with abnormal defecation and had a malformation of penis. The animal presented abdominal enlargement and had a stenosed anal opening, incomplete fusion of the distal urethra and prepuce and a vestigial penis without prepuce and urethral opening. The urethral opening was detected ventral to the anus, and the puppy also showed passage of watery feces through a cloacal orifice. In abdominal radiographs megacolon and type II atresia ani were observed. In addition, a recto-genital fistula was observed in the retrograde positive-contrast urethrocystography.

In the present case, three of the pathologies were corrected.

 Hypospadias: amputation of the remaining penis, prepuce and urethra unfused followed by wound closure.

 Recto-genital fistula: the orifice into the cloaca was located using a 22-gauge intravenous catheter; the edges were resected. A purse-string suture was placed which was reinforced with a horizontal mattress suture both with 4-0 polypropylene.

 Type II atresia ani: colostomy and anoplasty were performed in the puppy.

The puppy recovered and defecated normally after surgery, thereby continuing to date. It is important to establish a diagnosis approach to perform the correct surgical management.