title: Hereditary esophageal dysfunction in the Miniature Schnauzer dog.
abstract: Miniature Schnauzers maintained in a colony for 9 years were used to study the inheritance of esophageal dysfunction (canine achalasia, megaesophagus). All dogs were evaluated radiographically, using a barium swallow contrast technique which clearly distinguished normal and affected pups. At 4 to 6 months of age, all affected dogs had recovered clinically except one, and radiographic evidence of dysfunction was markedly diminished. None of the affected dogs required a special feeding regimen. Analysis of breeding pairs revealed a ratio of 9 affected/11 normal dogs when an affected male was mated with a normal female, and a 13/3 ratio was observed when two affected dogs were mated. These ratios were compatible with a simple autosomal dominant or a 60% penetrance autosomal-recessive mode of inheritance. Outbreeding to an affected Miniature Schnauzer/Poodle crossbred dog resulted in only two of 30 affected pups, indicating a polygenic mode of inheritance in outbred populations.
mesh_terms: D000818:Animals; D001947:Breeding; D004283:Dog Diseases / Q000151:congenital / Q000000981:diagnostic imaging / Q000235:genetics*; D004285:Dogs; D004947:Esophagus / Q000002:abnormalities* / Q000000981:diagnostic imaging; D005260:Female; D008098:Litter Size; D008297:Male; D011247:Pregnancy; D011859:Radiography