In the different types of tumours in dogs, including breastcancer, there are a number of polymorphisms described in the D-loop region, MT-CYTB, MT-COI and MT-ND1 gene, and a missense mutation in epithelioma glandulae sebacei resulting in the amino acid change p.T193N leading to a change in MT-ND1 (Slaska et al. 2013a, b). The gene discussed is MT-CO1; the disease is neoplasm.