Bovine malignant catarrhal fever

Bovine Malignant Catarrhal Fever (BMCF) is a highly fatal disease affecting cattle worldwide. It is caused by a group of viruses within the Herpesviridae family, primarily by two distinct viruses: Ovine herpesvirus 2 (OvHV-2), which is prevalent in sheep, and Alcelaphine herpesvirus 1 (AlHV-1), found in wildebeest. Despite its name, BMCF can affect a wide range of ruminants beyond cattle, including deer, bison, and pigs, though sheep and wildebeest, the primary carriers, remain asymptomatic.

Symptoms and Diagnosis

The clinical signs of BMCF are diverse and can include high fever, corneal opacity, nasal discharge, lymphadenopathy (swelling of the lymph nodes), and erosions in the mucous membranes of the mouth and nose. Affected animals may also exhibit CNS (central nervous system) symptoms, such as depression, aggression, or other neurological signs due to the widespread inflammation caused by the virus.

Diagnosis of BMCF is challenging due to its nonspecific symptoms, which can resemble those of other diseases like foot-and-mouth disease, bluetongue, and mucosal disease. Laboratory tests, including PCR (polymerase chain reaction) and virus isolation, are necessary to confirm the presence of the causative herpesvirus.

Transmission and Epidemiology

BMCF is not directly contagious among cattle. Instead, transmission typically occurs through contact with infected sheep or wildebeest, which shed the virus in their secretions and excretions. The disease has a worldwide distribution but is more common in regions where cattle are raised in close proximity to sheep or wildebeest.

Prevention and Control

There is no vaccine available for BMCF, making prevention challenging. Control measures focus on minimizing contact between cattle and the reservoir species (sheep and wildebeest). This can include physical barriers or separate grazing periods. Early detection and culling of affected animals are also critical to prevent the spread of the disease within a herd.

Treatment

There is no specific treatment for BMCF. Management of the disease is supportive, focusing on relieving symptoms and preventing secondary infections. However, due to the high mortality rate, euthanasia is often recommended to prevent suffering.

Research and Future Directions

Research into BMCF is ongoing, with efforts focused on understanding the virus's pathogenesis, developing diagnostic tools, and exploring potential vaccines. Understanding the immune response in asymptomatic carriers like sheep and wildebeest may also provide insights into disease resistance and potential treatment strategies.

External Links

• Wikimedia Commons - for images related to BMCF and its causative agents.
• World Organisation for Animal Health (OIE) - for updates on BMCF and international standards for disease control.

See Also

• Herpesviridae
• Viral diseases of animals
• Zoonosis