Studies on Malignant Catarrhal Fever in Wild Ruminants

Wild and domestic animals inhabiting Sofia and Varna zoos showing clinical symptoms of malignant catarrhal fever (MCF) were investigated. Clinical and pathological studies were carried out with 16 wild and 8 domestic ruminants. Typical clinical symptoms for MCF were confirmed. Samples for virus isolation and molecular biological investigations were obtained from dead animals. Ten percent suspensions from the lymph nodes, spleens, lungs, brain samples, and buffy coats in phosphate buffered saline (PBS) were used for viral isolation. Primary and permanent cell cultures: rabbit kidney, Madin Darby bovine kidney (MDBK), embryonic bovine trachea (EBTR). Bovine trachea (TTr) and VERO cells were used. Viruses with peculiarities of herpesviruses were isolated from bison , yak, camel, Cameroon goats and hippopotamus on MDBK cell culture. The isolated strains were confirmed as MCF viruses by classical and nested polymerase chain reaction (PCR). The size of the amplicons after classical PCR was 422 bp, and 238 bp after nested PCR. Thirty seven serum samples originated from 17 sheep, 13 Cameroon goats, 5 mouflons and two bison were investigated serologically by a competitive-inhibition ELISA for spread of MCF. In 21.4% of sheep sera, 30.7% of Cameroon goat sera, and 50% of bison sera antibodies against MCF were found. The total distribution of MCF antibodies in wild and domestic ruminants was 27%.