A 3-month-old fawn from a group of 12 captive white-tailed deer (Odocoileus virginianus) displaying cutaneous lesions was presented to the Mississippi Veterinary Research & Diagnostic Laboratory for necropsy. Postmortem examination identified multiple discrete, round, alopecic, flat, proliferative dermal lesions scattered along the skin of the lips, muzzle, pinna, ventral thorax, medial limbs, and most notably the abdomen. Multiple ulcers were present on the commissures of the lips, dorsal surface of the tongue, and left caudal buccal surface of the oral cavity. The abdomen was filled with fibrinopurulent exudate and ruminal contents. Multiple to coalescing transmural ulcers were identified in the rumen. Histopathological evaluation of the skin revealed markedly thickened epidermis and focal areas of superficial dermal fibrosis, intracytoplasmic, eosinophilic inclusions in swollen keratinocytes and lymphocytic and plasmacytic perivascular dermatitis. The rumen ulcers were surrounded with necrotic cellular debris mixed with fibrin, bacteria, hemorrhages, and a collection of mixed inflammatory cells. Some swollen ruminal mucosal epithelia had eosinophilic intracytoplasmic inclusions. Poxvirus was isolated from the skin and rumen tissue specimens. Electron microscopy detected viral particles with poxvirus morphology. Polymerase chain reaction assays detected A21, a gene conserved within family Poxviridae, in the skin and rumen tissues. Phylogenic analysis of the A21 sequences indicated that the viral isolate (M10-9055) was closely related to known members of genus Cervidpoxvirus. In conclusion, findings indicate that Deerpox virus can produce extensive lesions in white-tailed deer.

Bovine viral diarrhea virus 1 (BVDV-1) is associated with mild or subclinical infections, whereas BVDV-2 is frequently implicated in outbreaks of severe thrombocytopenia and acute fatal disease. In the present study, the carcass of a beef breed cow and tissue samples of a beef calf were received for laboratory diagnosis. Both animals exhibited severe clinical signs compatible with thrombocytopenia or hemorrhagic syndrome. Direct fluorescent antibody test (DFAT) failed to detect BVDV antigen in the tissue specimens of both cases. However, immunohistochemistry (IHC) revealed the presence of BVDV antigen in oral and esophageal mucosa and Peyer patches of the beef breed cow. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) detected BVDV-2 in selected tissues of both animals. Subsequently, BVDV was isolated from both cases and subjected to genetic and serologic characterizations. Mutations in the 5'-untranslated genomic region (5'-UTR) primer and probe binding sites and the E2 gene were associated with reduced efficiency of an established real-time RT-PCR assay and amino acid alterations in the E2 glycoprotein, respectively. Both viral isolates were classified by real-time RT-PCR and phylogenetic analysis as BVDV-2 subgenotype a. Unlike BVDV reference strains Singer and 125c, the isolates cross-reacted with anti-BVDV-1 and anti-BVDV-2 reference sera, indicating antigenic variations in field isolates. The isolates also showed reduced reactivity to porcine anti-BVDV antiserum (the raw serum used to produce BVDV DFA conjugate). In summary, data from the present investigation indicated that genetic and antigenic variations affected the performance of detection assays, especially DFAT, highlighting the need for regular evaluation and modification of BVDV tests.