| Canarypox virus (CNPV) is an avipoxvirus and etiologic agent of canarypox, a disease of birds both in the wild and in commercial aviaries, where significant losses result. Canarypox has been described broadly as the poxviral disease of passeriform (song) birds, efficiently causing disease in passerine hosts compared to galliform (domestic fowl) and columbiform (pigeon) hosts. However, passerine host preferences exist, and current International Committee on Taxonomy of Viruses classification differentiates between CNPV and several other passerine isolates. CNPV produces clinical signs similar to generalized poxviral infections of other birds, including both cutaneous and diptheretic disease forms caused by the prototypical galliform avipoxvirus, fowlpox virus (FWPV), and including proliferative and necrotic changes in epithelial tissues of the dermis, notably around the eyes and commissures of the beak, feet, and respiratory tract. Canarypox, however, is generally associated with higher mortality rates than seen in fowlpox, commonly approaching 100%, and may occur without characteristic skin lesions. Histologically and ultrastructurally, CNPV undergoes morphogenic stages similar to FWPV and other chordopoxviruses (ChPV), causing type A and B intracytoplasmic inclusions in epithelial and mononuclear cells of permissive hosts; however, CNPV may have a broader tissue tropism than FWPV (Tulman et al., 2004). |
