Jeopardy of Lyssavirus infection in relation to hemato-biochemical parameters and diagnostic markers of cerebrospinal fluid in rabid calves

Abstract

Rabies is caused by a single-stranded virus with ribonucleic acid belonging to the genus Lyssavirus in the Rhabdoviridae family. This disease causes 100% fatality of exposed non-vaccinated humans and animals. Many aspects of rabies still ambiguous; therefore, the hemato-biochemical effects of Lyssavirus infection and the potential diagnostic markers of cerebrospinal fluid (CSF) in rabid calves were investigated. Six female Frisian cross-bred calves (6–7 months of age) were accidentally exposed to bites from stray dogs. Twenty days later, the calves showed anorexia, severe ptyalism, erected ears, fatigue, cough, and neurological signs including continuous mooing for the majority of the day and sometimes rubbing their heads against hard objects. The rabid calves died within 4–6 days after the appearance of these aforementioned signs. The cerebellum showed lymphocytic leptomeningitis with or without hemorrhage, along with characteristic Negri bodies; in the respiratory system, pronounced suppurative bronchopneumonia occurred. There were mild vicissitudes in the erythrogram without significant vicissitudes in the blood indices. The leucogram showed significant leucopenia, lymphopenia, and monocytopenia with marked granulocytosis. Blood gas analysis publicized mixed respiratory and metabolic acidosis. Laboratory findings of cerebrospinal fluid (CSF) revealed pleocytosis, lymphocytosis, and significant increases in glucose, cholesterol, S–100B, total proteins, globulins, IgA, haptoglobin, TNF-α, and IL-1 levels. We concluded that presence of lymphocytic pleocytosis along with the elevation of glucose, cholesterol, S–100B, and pro-inflammatory cytokines could be used as a potential markers for rabies in bovines. Also, presence of pneumonia with mixed respiratory and metabolic acidosis in raid claves could be complications for Lyssavirus infection.