Gastrointestinal and respiratory infections caused by micro-organisms sensitive to doxycycline and/or gentamicin like Bordetella, Campylobacter, Chlamydia, E. coli, Klebsiella, Haemophilus, Mycoplasma, Pasteurella, Rickettsia, Salmonella, Staphylococcus and Streptococcus spp. in calves, goats, poultry, sheep and swine.