Imerslund-Grasbeck Syndrome 1

Imerslund-Grasbeck Syndrome (Border Collie type)

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Price: $45.00Price: £40.00

Breeds: Australian Shepherd/Border Collie, Border Collie, Bordoodle, Mixed Breed (Dog), Unspecified Breed, Working Sheepdog


Canine Imerslund-Grasbeck Syndrome (IGS), or cobalamin malabsorption, is a disorder which prevents a dog from absorbing adequate levels of Vitamin B12, or cobalamin. Cobalamin is normally taken in through the small intestines. Dogs with IGS cannot absorb the vitamin and quickly begin to show symptoms of deficiency.

Symptoms of IGS typically appear within 6-12 weeks after birth. A puppy is born with a certain amount of Vitamin B12, but after the stored vitamin is depleted, the puppy will exhibit signs of deficiency. Symptoms include: anemia, lethargy, failure to thrive, and lack of appetite. While IGS cannot be cured, the disorder can be managed with regular supplementation of cobalamin.

Imerslund-Grasbeck Syndrome is inherited as an autosomal recessive condition. This means that the mutated gene can be inherited from either parent. Furthermore, a dog must inherit two copies of the mutated gene to have IGS, one from each parent. Dogs that have only one copy of the mutated gene are carriers of the mutation. Since carriers do not exhibit any symptoms of the disorder, DNA testing is an important tool to ensure the optimum health of puppies.

Possible Results

Genotype Description
IGS/IGS Affected: Dog has two copies of IGS mutation and will be affected. The gene will be passed to every offspring.
n/IGS Carrier: Dog has one copy of the IGS mutation. The dog is not affected by IGS but may pass the gene to offspring.
n/n Clear: Dog is negative for the mutation associated with IGS.


A Frameshift Mutation in the Cubilin Gene (CUBN) in Border Collies with Imerslund-Gräsbeck Syndrome (Selective Cobalamin Malabsorption) Marta Owczarek-Lipska, Vidhya Jagannathan, Cord Drögemüller, Sabina Lutz, Barbara Glanemann, Tosso Leeb, Peter H. Kook PLoS One. 2013; 8(4): e61144. Published online 2013 Apr 6. doi: 10.1371/journal.pone.0061144 [PMID: 23613799]