BonniDune Kennel is located in
Southern Indiana, USA. Although I started
with German Shepherd Dogs, today BonniDune is
dedicated to showing, trialing and producing
sound, versatile Border Collies.
BonniDune is proud to be recognized as an AKC Breeder of Merit.

Puppies Born December 25, 2013

What Is Igs In Border Collies


Border Collies are highly intelligent and energetic dogs known for their herding abilities. However, like any other breed, they can be prone to certain genetic conditions. One such condition is IGS (Imerslund-Gräsbeck Syndrome), which affects the absorption of vitamin B12 in the body. In this article, we will explore what IGS is and how it impacts Border Collies.

Understanding IGS

Imerslund-Gräsbeck Syndrome, also known as Selective Cobalamin Malabsorption (SCM), is an autosomal recessive disorder that affects the transport of vitamin B12 in the small intestine. Vitamin B12 is essential for various bodily functions, including the production of red blood cells, normal neurological development, and the functioning of the immune system.

Genetics and Inheritance

IGS is caused by a mutation in the AMN gene, which is responsible for encoding a protein involved in the absorption of vitamin B12. The condition is inherited in an autosomal recessive manner, which means that both parents must carry the mutated gene for a puppy to be affected. If both parents carry the gene, there is a 25% chance of each puppy inheriting the disorder.

Symptoms and Diagnosis

Border Collies affected by IGS may exhibit a range of symptoms, including poor appetite, weight loss, failure to thrive, lethargy, and anemia. These signs typically appear in puppies around 6 to 8 weeks of age. To diagnose IGS, a blood test is conducted to measure vitamin B12 levels. Additionally, genetic testing can be performed to identify carriers of the mutated gene.

Treatment and Management

While there is no cure for IGS, the condition can be managed with lifelong vitamin B12 supplementation. Regular injections or oral supplements are given to affected dogs to maintain adequate levels of vitamin B12 in their bodies. With proper treatment, most Border Collies with IGS can lead normal, healthy lives.

Preventing IGS

As IGS is a genetic disorder, prevention is focused on responsible breeding practices. It is crucial for breeders to screen potential breeding dogs for the AMN gene mutation to prevent the transmission of IGS to future generations. Genetic testing can help identify carriers and ensure that only healthy dogs are used for breeding.


Imerslund-Gräsbeck Syndrome is a rare genetic disorder that affects the absorption of vitamin B12 in Border Collies. While it can lead to serious health issues if left untreated, timely diagnosis and proper management can allow affected dogs to live fulfilling lives. Responsible breeding practices play a vital role in preventing the spread of IGS and ensuring the overall health and well-being of Border Collies.

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