Congenital idiopathic megaesophagus (CIM)

Congenital idiopathic megaesophagus (CIM) is characterized as a gastrointestinal motility disorder preventing the normal transport of food within the stomach by reduced peristaltic activity and dilation of the esophagus. Affected dogs show regurgitation of meal and water and therefore failing to thrive. Complications as aspiration pneumonia can occur.
In the breed German Shepherd, a genetic variant has been identified that is associated with an increased risk of CIM. Approximately one third of the homozygously affected female dogs showed symptoms of CIM, while as many as half of the homozygously affected male dogs showed symptoms. However, other, unknown factors play a role in the development of megaesophagus. Many of the affected dogs showed symptoms under one year of age. The genetic test enables targeted breeding to preferentially spread the non-risk allele in the breed.