Atresia ani und rektokutane Fistel bei einem adulten Meerschweinchen (Cavia porcellus)

Zusammenfassung

Ein 4 Jahre alter, seit seiner Geburt mit einem männlichen Geschwistertier in einem Außenstall gehaltener Meerschweinchenbock wurde mit gutem Allgemeinbefinden zur Kastration vorgestellt. Bei der allgemeinen Untersuchung fiel eine kleiner als üblich ausgebildete Perinealtasche auf. An deren kaudalem Ende befand sich eine kleine Einziehung, die nach 3mm blind endete. Bei der weiteren Untersuchung in Narkose zeigte sich kaudodorsal der Perinealtasche eine Fistelöffnung, in der leicht vorgefallene Schleimhaut sichtbar war. Die Öffnung mündete in einen Richtung Wirbelsäule ziehenden Kanal. Nach Instillation eines Kontrastmittels in die Fistelöffnung stellte sich der normal erscheinende Enddarm röntgenologisch kontrastgefüllt dar. Aus der Fistelöffnung konnte der Absatz normaler Kotpellets beobachtet werden. Das Tier wies keine weiteren Fehlbildungen oder Symptome auf. Das Geschwistertier präsentierte sich unauffällig. Es wurde die Diagnose einer Atresia ani mit Bildung einer rektokutanen Fistel gestellt. Da das Tier keine klinischen Symptome zeigte und der Kotabsatz durch die Fistel möglich war, wurde auf eine Therapie verzichtet. Nach Wissen der Autoren nach handelt es sich bei diesem Fallbericht um die zweite Beschreibung einer Atresia ani bei einem Meerschweinchen. Die Besonderheiten des vorliegenden Falls sind das hohe Alter des Tieres, in dem die Missbildung festgestellt wurde, in Kombination mit dem Geschlecht sowie die Ausbildung einer einzelnen rektokutanen Fistel.

Summary

A 4-year-old, male guinea pig in a good general condition was presented for a routine castration. Since its birth, the animal had been kept outdoors with a male sibling. At the initial examination the perineal sac was smaller compared to other intact male guinea pigs. At the caudal end of the perineal sac a small dimple was noted, that ended blindly after 3mm. The following examination under anaesthesia revealed a fistula opening 1cm caudodorsally to the anus. The skin around the opening was bulging but without any signs of inflammation. Slightly protruding and reddened mucosa was visible inside the opening. After instillation of a contrast agent into the fistula a radiograph showed a contrast-filled caudal region of the large intestine. The intestine appeared to be normal and no other abnormalities were present. The excretion of normal faeces through the fistula was visible and atresia ani with a rectocutaneous fistula was diagnosed. The examination of the male sibling showed a normally developed anus. As the guinea pig had no clinical signs or associated malformations apart from the smaller perineal sac and the passage of normal faeces was possible through the fistula opening, no therapy was scheduled. To the authors’ knowledge, this is the second report of this congenital abnormality in a guinea pig. The characteristics of this case include the high age of the animal at diagnosis of the atresia ani, the gender and the formation of a single rectocutaneous fistula.

Schlüsselwörter

Atresia ani - Analstenose - Fistel - angeborene Missbildungen - Meerschweinchen

Key words

Atresia ani - imperforate anus - fistula - congenital abnormalities - guinea pig

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