Lipemic blood samples are commonly encountered in small animal practice and are usually due to recent ingestion of a fat-containing meal; however, lipemic samples collected after an overnight fast are abnormal: they are the result of genetic or acquired defects in the metabolism of triglyceride-carrying lipoproteins. Genetic causes of lipemia are rare in the dog, but an inherited abnormality of lipoprotein lipase, the enzyme that clears these lipoproteins from the circulation, may be responsible for idiopathic hyperlipoproteinemia in Miniature Schnauzers. Fasting lipemia is more commonly seen in dogs with diabetes mellitus, hypothyroidism, hyperadrenocorticism, or nephrotic syndrome. In such cases, the lipemia is usually corrected with effective treatment of the primary condition. Dogs with uncontrolled lipemia are at risk of developing acute pancreatitis, and, in cases where no underlying disease can be identified, the patient should be prescribed a low-fat diet. Dogs unresponsive to dietary therapy may be candidates for specific lipid lowering agents.