Intestinal Lipid Malabsorption (ILM)

Intestinal lipid malabsorption in the Australian Kelpie is a hereditary metabolic disorder in which the absorption and processing of dietary fats in the intestine are impaired. Affected dogs are unable to properly utilise long-chain fatty acids, which are important components of the diet. As a result, they suffer from inadequate nutrient supply despite normal or even increased food intake.

Typical symptoms appear at a very early age, in some cases before six weeks of age. Affected puppies initially appear normal, but soon develop markedly reduced growth. They often reach only about one-third to one-half the size of their littermates and gain very little weight. Common signs include greasy, pale yellow, poorly formed faeces (steatorrhoea), frequent passage of large volumes of faeces, and a distended abdomen. A rough, wiry coat and generally poor body condition are also typical. In contrast to other similar disorders of energy metabolism, affected puppies do not show lethargy.

As the dog ages, the clinical signs may become less pronounced. From around six months of age, many dogs show milder symptoms, particularly when fed solid food and, where appropriate, supplemented with digestive enzymes. However, affected dogs usually remain smaller, continue to produce larger amounts of faeces, and have a persistent intolerance to high-fat diets.

The condition is caused by a variant in the ACSL5 gene (Acyl-CoA Synthetase Long Chain Family Member 5). This gene provides the instructions for an enzyme that plays a key role in the absorption and processing of long-chain fatty acids in the small intestine. If this function is absent, fats cannot be properly absorbed. The disorder is inherited in an autosomal recessive manner. This means that a dog will only develop the symptoms of the disease if it inherits the altered gene variant from both parents. Carrier animals typically show no clinical signs but can pass the disease on to their offspring.