Spitz nevus was first described by Sophie Spitz in 1948 as juvenile melanoma. The lesion is a benign melanocytic tumor, which consists of epiteloid- and spindelshaped cells. Histological is Spitz nevus difficult to distinguish from malign melanomas and spitzoid melanomas. Loss of symmetry, loss of maturation in the deep component, nuclear polymorphism and hyper chromatic nucleus are features which can be found in melanomas. Some of these features are often seen in Spitz nevus.

Diabetes mellitus (DM) is a relatively common endocrine disease in dogs and is more common in certain breeds than others, e.g. Nordic spitz breeds. Within the Swedish and Norwegian Elkhound population, female dogs are almost exclusively affected. The hypothesis in this study is that Swedish- and Norwegian Elkhounds develop DM during the progesterone phase of estrous (diestrous or pregnancy). Medical records from 51 female dogs of the breeds Swedish and Norwegian Elkhound were studied.