Inherited Congenital Extrahepatic Portosystemic Shunts in Cairn Terriers

Abstract

The pathogenesis of congenital portosystemic shunt (CPSS) in dogs still is incompletely understood. In Irish Wolfhounds and Yorkshire Terriers, CPSS is reported to be hereditary. The aim of this study was to investigate a possible genetic basis and the mode of inheritance of CPSS in Cairn Terriers. Between July 1990 and July 2001, 6-week-old pups of the Dutch Cairn Terrier population were screened by measuring venous ammonia concentrations and in the presence of hyperammonemia by ultrasonography, autopsy, portal vein angiography, or exploratory celiotomy. The same successfully operated female was used 3 times in test matings with an unrelated affected male, her unaffected sire, and an affected offspring. The prevalence of CPSS in the general Cairn Terrier population, the direct progeny of frequently used males, and the offspring of the test matings were tested for significant differences. In total, 6,367 Cairn Terriers were screened; 32 males and 26 females had CPSS. In 3 large family groups, significantly higher prevalences were found compared with the general population (P < .0001, P < .0001, and P < .044). The prevalence of CPSS in the offspring of the test matings was significantly higher (P < .002) than in the general population. No sex predisposition occurred among the affected dogs. The higher prevalence of CPSS in the test matings and the 3 family groups compared with the general population indicates that CPSS in Cairn Terriers is a genetic disease. The inheritance is autosomal and most likely polygenic or monogenic with variable expression.

Inherited liver shunts in dogs elucidate pathways regulating embryonic development and clinical disorders of the portal vein

“…Although the genetic basis of CPSS in dogs is not clear yet, many authors have demonstrated that congenital shunts are more frequently diagnosed in purebred dogs and that a number of breeds are predisposed to it (Hunt 2004; Tobias 2003), which indicates an inherited basis for this disease (Meyer and Rothuizen 1991; van Straten et al 2005). An equal frequency of affected males and females was generally reported (Hunt 2004; van Straten et al 2005). In addition, EHPSS and IHPSS were very rarely seen in the same breed (Hunt 2004; Krotscheck et al 2007; Martin 1993; Tobias and Rohrbach 2003; Vulgamott 1985; Winkler et al 2003).…”

“…Extrahepatic shunts occur in small dog breeds with a predisposition in Cairn terriers (van Straten et al 2005), Yorkshire terriers (Tobias 2003; Tobias and Rohrbach 2003), Jack Russell terriers (Hunt 2004), Dachshunds (van den Ingh et al 1995), miniature schnauzers, Havanese, Dandie Dinmont terriers (Tobias and Rohrbach 2003), and Maltese (Tisdall et al 1994). …”

Aberrant Expression and Distribution of Enzymes of the Urea Cycle and Other Ammonia Metabolizing Pathways in Dogs with Congenital Portosystemic Shunts

“…CPSS was suspected upon clinical symptoms and increased basal plasma ammonia concentrations as previously described [30]. The diagnosis and localization of the CPSS (IHPSS or EHPSS) was made by ultrasonography and confirmed during surgery.…”

“…This occurs via an intrahepatic (IHPSS) or an extrahepatic portosystemic shunt (EHPSS). CPSS are reported to occur in 0.18 percent of all dogs [29], but the reported incidence varies between 1–5 percent in breeds like the Irish wolfhound and the Cairn terrier [30]–[32]. A hereditary pattern has been documented in several breeds [30]–[34].…”

“…CPSS are reported to occur in 0.18 percent of all dogs [29], but the reported incidence varies between 1–5 percent in breeds like the Irish wolfhound and the Cairn terrier [30]–[32]. A hereditary pattern has been documented in several breeds [30]–[34]. In humans, CPSS are extremely rare [35]–[37].…”