Intestinal Cobalamin Malabsorption (Border Collie Type)

General Information: Intestinal cobalamin malabsorption (border collie type) is an inherited disorder in dogs that prevents the production of a protein necessary for cobalamin absorption. Affected dogs, from as early as 14 weeks, show increased methylmalonic acid levels in their urine, a sign of cobalamin deficiency. Symptoms include anorexia, lethargy, poor weight gain, and in severe cases, hepatic encephalopathy leading to seizures, coma, and death. These dogs also exhibit increased urinary proteins and decreased blood cell synthesis, resulting in anemia. Lifelong cobalamin supplementation leads to remission in most cases, though elevated urinary proteins persist.

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 of the CUBN gene can determine if a dog is a carrier of intestinal cobalamin malabsorption (border collie type), an autosomal recessive disorder requiring two copies of the mutated gene for the disease to manifest. Carrier dogs usually show no symptoms but breeding two carriers can produce affected pups, with a 25% chance of disease and a 50% chance of being a carrier in each pup. Reliable genetic testing is crucial for informed breeding practices to prevent affected litters. To eliminate this mutation from breeding lines, it is advised not to breed known carriers together. Dogs that are not carriers of the mutation do not have an increased risk of producing affected pups.