Nosematosis (encephalitozoonosis) in a litter of blue foxes after intraueterine injection of Nosema spores.

During recent years, nosematosis (syn. encephalitozoonosis) has caused serious losses among young blue foxes (Alopex lagopus) in Norway; the causative organism is considered to be Nosema (syn. Encephalitozoon) cuniculi. Descriptions of clinical symptoms and patho-morphological changes on which the diagnosis is based have been given in previous papers ( 1972, 1974, 1976). The disease, as a rule, is restricted to certain litters, in which several or all pups are affected, a pattern which indicates a congenital infection. In a previous report we presented experimental evidence for transplacental transmission, after oral infection of the dam ( 1974). Although we feel that oral exposure, resulting in subclinical infection, is the most common way in which the dams are infected, field observations indicate that the organisms, in rare cases, may be transmitted from the male during matins.