Introduction

The range of viral skin disease in animals is very wide and involves many agents which also have significant systemic effects. Comprehensive consideration of all of these infections is beyond the scope of this review and attention will therefore be concentrated on infections of terrestrial mammals and on diseases of the general body surface. Diseases in which the skin signs form a minor part will only be mentioned briefly. Zoonotic infection is not considered here but readers are referred to the CRC handbook on viral zoonoses.

Virus infections of the skin may be divided into those in which the skin disease is the principal feature (Tables 13.1–13.3 below) and those where skin lesions form a subsidiary part of the generalized disease (Tables 13.4 and 13.5 below). Although this division is arbitrary and does not allow for diseases in which severe skin and systemic infections coexist, it provides a framework for consideration of the large and diverse range of viral skin diseases.

The great majority of virus infections in which skin signs predominate are caused by DNA viruses and, in particular, the poxviruses (Table 13.1). RNA viruses are represented only by the retroviruses (feline sarcoma and feline leukaemia viruses), which are responsible for neoplastic disease (see Table 13.3).

Poxvirus infections

The poxviruses are composed of two subfamilies, of which only one, the Chordopoxvirinae, affects vertebrates.