**10. References**


**11** 

*1Greece 2USA* 

**Atresia Ani in Dogs and Cats** 

*Aristotle University of Thessaloniki,* 

*University of Florida Gainesville,* 

Lysimachos G. Papazoglou1 and Gary W. Ellison2 *1Department of Clinical Sciences, Faculty of Veterinary Medicine,* 

*2Department of Small Animal Clinical Sciences, Health Science Center,* 

Congenital deformities of the anorectum are rarely encountered in small animals with atresia ani being the most common one. Atresia ani is a congenital defect of the anorectum, resulting in anal canal closure and /or abnormal routing of feces (Bright & Bauer, 1994). Among large animals congenital atresia ani most often occurs in pigs and calves and is considered hereditary. In these species atresia may be seen as a separate entity or in conjunction with other malformations of the distal vertebral column, urogenital tract and sometimes with intestinal atresia or colonic agenesis (Kilic & Sariepler, 2004; Maxie, 2007). In pigs atresia is associated with a high mortality rate but selective breeding decreased its

Atresia ani is uncommonly described in dogs and it is even less frequently reported in cats; the true incidence of this abnormality is difficult to determine and may be greater than reported because many newborn puppies and kittens are euthanatized before being evaluated based on the hypothesis that surgical correction is unsuccessful; additionally unpublished data may hide true prevalence as complications associated with surgical correction of these deformities are common (Prassinos et al.,. 2003; Mahler & Williams, 2005; Viana & Tobias, 2005). According to a review of Veterinary Medical Database atresia ani in dogs accounts for 0.0007 with females more likely to be affected than males (female/male =1.79/1) [Viana & Tobias, 2005]. Canine breeds overpresented include Finish spitz, Boston teriers, Maltese, chow chow, German shorthair pointer, toy poodle and miniature schnauzer (Viana & Tobias, 2005). In cats females are more commonly affected than males (Suess et al.,

The embryologic development of the canine and feline anorectum resembles that of the human development (Greiner, 1972; Amand, 1974; Suess et al., 1992; Sadler, 1995; Viana &

**1. Introduction** 

**2. Epidemiology** 

occurrence (Partlow et al., 1993; Viana &Tobias, 2005).

1992; van de Broek et al., 1988; Tsioli et al., 2009, Tomsa et al., 2011).

**3. Normal and abnormal embryologic development** 

