German shepherd dogs (GSDs) are predisposed to an inherited motility disorder of the esophagus (the gullet), termed congenital idiopathic megaesophagus (CIM), in which the esophagus is enlarged and swallowing is ineffective. Affected puppies are unable to properly pass food into their stomachs and consequently regurgitate their meals and show a failure to thrive, often leading to euthanasia.
The disease affects males more than females which is thought to be due to the estrogen protection role in females.
Congenital Idiopathic Megaesophagus (CIM) is thought to be caused by a mutation in teh gene which encodes a receptor for melanin-concentrating hormone, a signaling molecule that is linked to appetite, weight, and gut motility.
The disease affects males more than females which is thought to be due to the estrogen protection role in females.
Congenital Idiopathic Megaesophagus (CIM) is thought to be caused by a variant in the gene which encodes a receptor for melanin-concentrating hormone, a signaling molecule that is linked to appetite, weight, and gut motility.
This is a high-risk factor variant and so dogs with the variant have higher risk of developing the disease.
Approximately one third of homozygous female dogs (CIM/CIM) showed symptoms of Congenital Idiopathic Megaesophagus (CIM), while up to half of homozygous male dogs (CIM/CIM) were clinically affected. However, other unknown factors also contribute to the development of megaesophagus. Many affected dogs exhibited symptoms before one year of age. The genetic test enables targeted breeding to reduce the frequency of the risk allele and promote the spread of the non-risk allele within the breed.
Dogs with one copy of the variant (N/CIM) were not shown to be at increased risk in the published study.
both sex and the variant can predict affection status in over 75% of dogs , and a genetic test is now available at Laboklin to facilitate breeding decisions aimed at reducing disease incidence.
Age of onset: Congenital Idiopathic Megaesophagus (CIM) primarily affects dogs early in life, but symptoms can persist into adulthood. While the condition is present from a young age, affected dogs often require lifelong management to address symptoms like regurgitation and aspiration pneumonia. Some dogs may outgrow the condition, but many will need ongoing care to ensure they can eat and drink properly.
