Figure 1

Antibody titre (log₁₀) to E. equi in 10 lambs inoculated with E. phagocytophila on day 0. Eight lambs were treated with oxytetracycline on day 6, while 2 lambs were untreated controls. The treated lambs were either given long-acting tetracycline or 5 days short-acting tetracycline. One of the treated lambs did not seroconvert (not shown) ◆ Treated and still with rickettsemia 1–3 months after treatment (3 lambs) ■ Treated and without rickettsemia 1–3 months after treatment (4 lambs) $ only 3 lambs * only 2 lambs △ Infected controls (2 lambs)