Tag archives: enzyme

Intestinal cobalamin malabsorption, also known as Amnionless Deficiency, Cobalamin Deficiency, Imerslund-Grasbeck Syndrome (IGS), and Vitamin B12 Deficiency, is an inherited disease found in the Australian Shepherd and related breeds (Miniature Australian Shepherd, Toy Australian Shepherd, Miniature American Shepherd). The disease is inherited in a recessive fashion and as such, dogs that inherit two copies of the mutation are at risk for the disease. The disease is caused by the inability to make adequate amounts of a protein that plays a role in absorption of certain nutrients from the intestinal tract and kidneys, including the B vitamin, cobalamin. Affected dogs have increased levels of methylmalonic acid in their urine (a sign of cobalamin deficiency) after weaning, but symptoms of disease may not be recognized by owners for months or years. Symptoms of disease include anorexia, lethargy, poor weight gain, poor muscle mass, and in rare circumstances, a severe neurological dysfunction called hepatic encephalopathy that can lead to altered mental state, seizures, coma and death. Affected dogs require treatment with cobalamin supplementation throughout their life.

Because of the severity of this condition and the fact that it is treatable, this test has been added to the breed-specific panels for Australian Shepherds and related breeds ...

Inborn Errors of Metabolism are a large group of inherited diseases that occur in both humans and dogs.  These disorders are well defined in humans but far less understood and recognized in dogs.  Individually, each of the inborn error of metabolism disorders is rare, but collectively they are an important and relatively common category of diseases in both man and dogs.  In dogs these disorders are rarely considered by veterinarians as the possible cause to be studied when their patient is ill and failing.  We recently told you the story of Rigel, a blue Afghan hound puppy who ultimately succumbed to one of the many known inborn error of metabolism disorders, mucopolysaccharidosis type 1.  We also discussed that if it were not for one astute veterinarian (out of many veterinarians who evaluated Rigel and his similarly affected sister, Trudy) their condition would have gone undiagnosed and this previously unrecognized genetic disorder would have continued to go unidentified in this breed. 

Cases like Rigel and Trudy’s raise an important question; how often are similarly "invisible" biochemical disorders occurring in dogs and going unrecognized and undiagnosed? Human and canine genetic research discoveries have illustrated repeatedly that ...