Effect of imidocarb dipropionate prophylaxis on the infectivity and immunogenicity of a Babesia bovis vaccine in cattle

Abstract

Imidocarb dipropionate (IDP), a potent prophylactic drug against Babesia bovis infections in cattle, was tested for its effect on the infectivity and immunogenicity of a live B. bovis vaccine marketed in Australia. At the recommended prophylactic dose rate of 3 mg/kg, IDP suppressed infectivity of the vaccine for at least 6 weeks. The vaccine infected all cattle inoculated either 8 weeks after treatment with 3 mg/kg, or 4 weeks after treatment with the recommended therapeutic dose of 1.2 mg/kg. These infections were, however, partially suppressed and the level of immunity to a subsequent heterologous virulent challenge was reduced. Cattle that failed to become infected after vaccination were fully susceptible to the challenge. It is concluded that where B. bovis vaccination is contemplated, prophylactic use of IDP should be avoided.

Chemoprophylaxis for babesiosis and anaplasmosis in cattle: case report

“…Imidocarb dipropionate has either chemoprophylactic action (dose of 1-2 mg/kg) or therapeutic action (dose of 4-5 mg/ kg) against B. bovis and B. bigemina (Kuttler & Johnson, 1986). Its half-life in plasma ranges from three to six weeks (de Vos et al, 1986;Vial & Gorenflot, 2006). After three weeks, the circulating levels start to gradually decrease, which allows controlled development of parasitemia and, thus, formation of immunity against the pathogenic agents, without developing the illness (Vial & Gorenflot, 2006).…”

“…Its use eliminates or prevents infection by these hematozoa and, as the plasma concentration decreases, gradual development of parasitemia takes place. This allows the animals to develop their own immunity, without any occurrence of clinical cases (Kuttler & Johnson, 1986;de Vos et al, 1986;Vial & Gorenflot, 2006).…”