FIG. 2. Unstained bovine fetal spleen cells 2 days postinfection with a high MOI of vesicular stomatitis virus, a Rhabdovirus, showing subtotal cell destruction; the cells appear pyknotic. Cells were observed using the 10X objective. (Lori Phalen and Carol Blair, Colorado State University, Fort Collins, CO)

FIG. 6. Unstained bovine fetal spleen cells 3 days postinfection with Orf virus, a Parapoxvirus, showing focal cell rounding at a low MOI. Cells were observed using a 4X objective. Note: you can see the CPE is focal at the low MOI, but it appears generalized at the high MOI. (Erica Suchman, Colorado State University, Fort Collins, CO)

FIG. 9. Unstained bovine fetal spleen cells 3 days postinfection with Orf virus, a Parapoxvirus, showing focal cell rounding at a high MOI. Cells were observed using a 10X objective. Note: the focal nature of the infection is easier to see under lower power magnification. (Erica Suchman, Colorado State University, Fort Collins, CO)

FIG. 10. Unstained bovine fetal spleen cells 4 days postinfection with a high MOI of bovine adenovirus, an Adenovirus, showing cell rounding and small amounts of clumping. Cells were observed using the 10X objective. (Erica Suchman, Colorado State University, Fort Collins, CO)

FIG. 12. Unstained bovine fetal spleen cells 3 days postinfection with a lower MOI than found in Fig. 11 of bovine viral diarrhea virus, a Flavivirus, showing generalized cell destruction and vacuoles, which are very difficult to see without staining. Cells were observed with a 10X objective. (Erica Suchman, Colorado State University, Fort Collins, CO)

FIG. 16. Unstained bovine fetal spleen cells 4 days postinfection with a low MOI of ovine parvovirus, a Parvovirus, showing generalized cell rounding (black arrows) and cell destruction (green arrows). Cells were observed with a 10X objective. (Erica Suchman, Colorado State University, Fort Collins, CO)

FIG. 17. Unstained bovine fetal spleen cells 4 days postinfection with a high MOI of bovine adenovirus, an Adenovirus, showing generalized enlarged cell rounding and cell clumping or clustering. Cells were observed with a 10X objective. Note, if observed very early in the infection, CPE will begin focally but rapidly becomes generalized. (Erica Suchman, Colorado State University, Fort Collins, CO)

FIG. 18. Unstained bovine fetal spleen cells 4 days postinfection with a low MOI of bovine adenovirus, an Adenovirus, showing generalized enlarged cell rounding and cell clumping or clustering. Cells were observed with a 10X objective. Note, if observed very early in the infection, CPE will begin focally but rapidly becomes generalized. (Erica Suchman, Colorado State University, Fort Collins, CO)