Chemoprophylaxis with tetracycline drugs in the immunisation of cattle against Theileria annulata infection

Gill B.S., Bhattacharyulu Y., Kaur D. and Singh A. 1978. Chemoprophylaxis with tetracycline drugs in the immunisation of cattle against Theileria annulata infection. International Journal for Parasitology8: 467–469. Three-month-old fully susceptible cross-bred calves were immunised against tropical theileriosis by treating 2-tick or 5-tick stabilate-induced Theileria annulata infections, with 1 or 2 doses of long-acting oxytetracycline (Pfizer) at 20 mg/kg body weight injected subcutaneously, or chlortetracycline at 16 mg/kg body weight daily for 8 days given orally. The treatment began on the day of the infection. After 45 days, the recovered calves were given severe 10-tick homologous stabilate challenge.The reactions were evaluated by noting fever, degree of anaemia, severity of the swelling of the regional lymph node, rate of parasitization of lymphocytes in the lymph node, and of erythrocytes in the peripheral circulation.The untreated calves developed a severe form of the disease with typical symptoms, which killed 1 of 4 and 2 of 5 calves receiving 2-tick and 5-tick stabilates, respectively. A total of 30 treated calves reacted mildly or not at all. Both the treated and untreated, recovered calves resisted completely the challenge infection which killed 3 of 4 susceptible controls. The effect of 1 dose of long-acting oxytetracycline was equal to that of 8 daily treatments with chlortetracycline; 2 doses of the oxytetracycline suppressed almost all clinical responses at immunisation.