Congenital Idiopathic Megaesophagus Risk Factor (German Shepherd Type)

General Information: Congenital Idiopathic Megaesophagus (CIM) in German Shepherds is characterized by a significant dilation and lack of motility in the esophagus, which prevents normal passage of food and water to the stomach. This condition typically becomes apparent at about 4 weeks of age, often coinciding with the transition from nursing to eating solid food. Affected puppies frequently regurgitate their food, leading to malnutrition, poor growth, and in some cases, life-threatening aspiration pneumonia. While the prognosis can be dire, with many puppies being euthanized due to severe complications, some can survive into adulthood with careful dietary management. A minority of affected dogs may experience improvement and potentially normal esophageal function by the age of one year.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing for Congenital Idiopathic Megaesophagus (CIM) in German Shepherds focuses on the MCHR2 gene to identify carriers of the disease, which is inherited in an autosomal recessive pattern. Dogs need two copies of the mutated gene, one from each parent, to exhibit symptoms of the disease. Carriers, possessing only one copy of the mutated gene, typically do not show symptoms but have a 50% chance of passing the mutation to their offspring. Each mating between two carriers yields a 25% chance that a puppy will inherit two copies and develop the disease. Therefore, genetic testing is crucial for making informed breeding decisions to decrease the prevalence of CIM. Breeding practices should avoid mating carriers to prevent producing affected offspring. Dogs that test clear of the mutation pose no risk of passing the disorder to their progeny.