|Other Names:||Copper hepatoxicosis, Copper storage hepatitis, Copper toxicosis, Copper-associated hepatopathy, Hepatic copper toxicosis, Wilson disease, BTCT, CT|
|Mutation:||chr10:61930410-61970122: 39.7 kb deletion|
Copper storage disease is an inherited metabolic condition affecting Bedlington Terriers. This disease is characterized by chronic copper accumulation leading to eventual copper toxicosis. Affected dogs are often asymptomatic up to 5 to 6 years of age after which they present with clinical signs of either acute liver failure or chronic liver failure. During this asymptomatic period copper continually accumulates in the liver and slowly damages liver cells. If only a few liver cells are damaged at a time, the liver can repair itself by regeneration or fibrosis. Chronic liver failure, the most common outcome of copper storage disease in Bedlington Terriers, occurs when there are not enough liver cells left to perform the normal functions of the liver. Chronic liver failure secondary to copper storage disease tends to occur in older dogs and signs of disease often include a pendulous abdomen from abdominal fluid accumulation, excessive thirst and urination and weight loss in addition to jaundice, lethargy, loss of appetite, depression and vomiting. Prognosis of the chronic form varies based upon the extent of liver damage when initially presented. Acute liver failure and hemolysis are less common outcomes of copper storage disease. This presentation usually occurs in younger dogs, and when an affected dog experiences a stressful event, such as whelping, air transport, kenneling or showing and the copper stores in the liver are released all at once. This sudden release of copper damages high numbers of liver cells and red blood cells all at once leading to liver and kidney failure. Signs of acute liver failure and hemolysis include jaundice, lethargy, loss of appetite, depression and vomiting. Dogs may also have decreased urine production, red-brown urine and a painful abdomen. This is an immediately life threating form of copper toxicosis with many dogs dying within 48 to 72 hours of initial symptoms despite treatment. If copper storage disease is not identified early and lifelong treatment is not started, most affected dogs die around three to seven years of age.
Genetic testing of the COMMD1 gene will reliably determine whether a dog is a genetic Carrier of copper storage disease. Copper storage disease is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the COMMD1 gene mutation. Reliable genetic testing is important for determining breeding practices. Because symptoms may not appear until adulthood, genetic testing should be performed before breeding. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Dogs that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
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