The effect of oxytetracycline treatment on immunity induced by Anaplasma centrale

• Published in: Veterinary microbiology Vol. 31; no. 1; p. 81
• Main Authors: Pipano, E, Krigel, Y, Markovics, A, Shkap, V
• Format: Journal Article
• Language: English
• Published: Netherlands 01-04-1992
• Subjects: Anaplasma - immunology; Anaplasmosis - drug therapy; Anaplasmosis - immunology; Animals; Bacteremia - drug therapy; Bacteremia - immunology; Bacteremia - veterinary; Bacterial Vaccines - immunology; Cattle; Cattle Diseases - drug therapy; Cattle Diseases - immunology; Female; Immunity, Active - drug effects; Oxytetracycline - pharmacology; Oxytetracycline - therapeutic use; Vaccination - veterinary
• ISSN: 0378-1135
• DOI: 10.1016/0378-1135(92)90143-H

Calves vaccinated with Anaplasma centrale were treated with 20 mg/kg of long-acting oxytetracycline (OTC/LA) before or simultaneously with vaccination or up to seven months later. Of 40 animals given one or two of OTC/LA from 3 to 13 days before vaccination, 23 become patent after vaccination, with an average prepatent period almost twice as long as that in non-treated vaccinated controls. Upon challenge with 2 x 10(8) A. centrale per dose all 17 previously non-patent calves showed average maximum parasitemias of 2 to 3.8%. Out of 30 calves treated with two to four doses of OTC/LA from one to four weeks after vaccination, 29 remained negative for A. centrale and reacted to challenge infection with average maximum parasitemias of 6.9-7.8%. Five out of 10 calves receiving OTC/LA simultaneously with the vaccination, and all of a separate group of 10 calves treated with a single dose seven days after vaccination, become patent an average of 51.6 and 63.5 d, respectively, after vaccination. Upon challenge, the five previously non-patent calves showed an average of 5.2% maximum parasitemia. In all groups, only rare parasites were seen in previously patent calves after challenge. Thirty calves treated with 2-4 doses of OTC/LA about six months after vaccination showed no or only a few parasites upon challenge. The above results show that treatment with single or multiple doses of OTC/LA a few weeks before or after administration of live A. centrale vaccine can interfere with elaboration of immunity.