ABSTRACT
This chapter reviews the pathobiology, especially gross and microscopic changes, associated with certain diseases of marine mammals. An effort was made to point out the relationships between certain stress factors and disease processes. Stressors that affect marine mammal health frequently act in combination to cause pathological change. Numerous viral agents identified in marine mammals have been implicated in explosive epizootics involving groups of susceptible animals in particular geographic locations, e.g., an outbreak of influenza in seals off Cape Cod and distemper in seals of the North Sea. Virology of marine mammals is a relatively new field of study and few cell lines are established. Seal pox virus was first identified in California sea lions by Wilson in 1969. The histologic lesions of seal pox differ, depending on the species of pinniped affected. In California sea lion and harbor seal, there is marked acanthosis with hyperkeratosis and parakeratosis, causing upward proliferation of the epidermis.
