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Experimental infection of colostrum-deprived calves with bovine viral diarrhea virus type 1a isolated from free-ranging white-tailed deer (Odocoileus virginianus)
2011
Raizman, Eran A. | Pogranichniy, Roman M. | Lévy, Michel Louis | Negron, Maria | Van Alstine, William
The objective of this study was to experimentally infect calves with bovine viral diarrhea virus (BVDV) isolated from free-ranging white-tailed deer. Twelve colostrum-deprived male Holstein calves were used. Eight were inoculated intranasally with a BVDV type 1a isolated from free-ranging white-tailed deer, and the other four were inoculated with the cell culture medium only and served as a control group. Whole blood, saliva, and nasal and rectal secretions were collected on days 0, 3, 7, 10, 14, 17, and 21 after inoculation for virus isolation and real-time reverse-transcriptase polymerase chain reaction (RT-PCR). On days 14 and 21, 4 calves in the infected group and 2 in the control group were euthanized; multiple tissue samples were collected for histopathologic study. Histopathologic changes included thymic atrophy and lymphoid depletion of the Peyer's patches in all 8 infected calves. The RT-PCR gave positive results with the buffy coat of all 8 infected calves, the nasal samples of 7, and the saliva samples of 2. Virus neutralization testing of the serum gave positive results for 4 of the 8 infected calves, and enzyme-linked immunosorbent assay of the serum gave positive results for 3. All of the samples from the control calves yielded negative results.
Show more [+] Less [-]Cryptosporidiosis in a commercial dairy cattle farm in Malaysia
2011
Slamah B. | Julaida S. | Saudah S. | Rasidah A. L. | Norhamizah A. H.
Cryptosporidium spp. was detected in 3 cows from rectal pinch
samples. Direct smear stained with Acid Fast and Kinyoun stain was used to detect the organism. Subsequent samplings also indicated positive for Cryptosporidiosis, whereby one of the animals died due to dehydration and severe clinical signs of diarrhea. The farm had contaminated water supply where two out of the four ponds were
positive for Cryptosporidium spp. whereas the municipal water supply was negative. The management of the farm was poor in terms of nutrition and cleanliness which led to Cryptosporidium spp. infection in the cattle compounded by stress factors. The mortality of the adult dairy cattle and calves was also high reaching up to
40%. The most common cause of death was leg weakness, severe dehydration and pneumonia in calves as a result of severe infections. Cryptosporidiosis is zoonotic and thus needs to be controlled to prevent outbreaks in the human population.
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