Atresia ani is a congenital defect of anorectum that can affect kitten and puppy. Affected animals will have abnormal routing of feces or anal canal closure (Bright & Bauer, 1994). It is uncommon to found atresia ani case in small animals and the true incidence of atresia ani cases cannot be determined as most of the affected newborn kittens or puppies will be euthanized due to the hypothesis that surgical repair for atresia ani is usually unsuccessful (Prassinos et al.,. 2003; Mahler & Williams, 2005;Viana & Tobias, 2005). Atresia ani is less acute in female when the cases is accompanied by a rectovaginal fistula as feces can be voided through vaginal and often the affected animals can live for few weeks without any serious illness (Kersjes et al., 1985). Rectovaginal fistula is a structure which accompanied atresia ani and it had been seen in certain atresia ani cases. The fistula connects the ventral wall of the terminal rectum with the dorsal wall of vagina which allowed feces to be voided through the vaginal opening (Suess ., 1982). Atresia ani can be classified into four different classes, which including congenital stenosis (Type I), imperforate anus alone (Type II), or combined with more cranial termination of the rectum as a blind pouch (Type III), and discontinuity of the proximal rectum with normal anal and terminal rectal development (Type IV), (Vianna and Tobias, 2005). The reported case in my report was a type II atresia ani kitten with presence of rectovaginal fistula.
2. Case report
Three months old, 0.6 kg female domestic short hair kitten was presented to University Veterinary Teaching Hospital, University Putra Malaysia, with a single perineum opening. The kitten was fed with dry biscuits, suckling from dam and was managed indoor together with four other healthy siblings. The owner had observed that she was the smallest among the siblings and the appetite was reduced and the kitten becomes inappetence for around five days before presentation.
During physical examination, the kitten appeared to be dull but responsive. The mucous membrane was pale and capillary refilled time was more than 2 seconds. There was no opening for the rectum and there was a perineal bulge. Greenish watery feces were observed dripping out from the vagina when kitten was straining to defecate. Hunchback position was observed when the kitten was standing and she was shivering during examination. During palpation on the abdomen, hard feces can be felt impacted along the intestine.