In my experience the best choice for treatment of goats leptospirosis is penicillin + Streptomycin(Trade name is Penstrep) 5 ml mornning and 5 ml evening for 3 days.
The combination of penicillin G and dihydrostreptomycin acts additive and in some cases synergistic. Procaine penicillin G and benzathine penicillin G are ...