Catalase deficiency is a rare disorder that leads to an abnormality in the gene coding for the anti-oxidative enzyme catalase. It is also known as hypocatalasemia and acatalasia. Catalase is involved in the metabolism of hydrogen peroxide which is generated during the respiration process in cells that produces oxygen. The gene is inherited as a recessive disorder so affected dogs have to have two copies of the gene, carriers will not develop the disease.

Affected dogs will show problems such as oral sores.