There are few good scientific reports of effective treatments for pinkeye. Since spontaneous recovery is not uncommon, some treatment prescriptions have been unjustly credited with being more effective. Most strains of M. bovis appear to be sensitive to tetracyclines, penicillin, erythromycin and neomycin. The use of aerosol sprays and powders generally cause additional irritation to infected eyes. These products cause increased tear secretion that in turn washes away the antibiotic.
Eye drops or ointments are better alternatives for mild or early cases of pinkeye.
They are non-irritating and do not result in excessive tear secretion. They do, however, have to be given in repeated doses to sustain adequate drug levels. The injection of a mixture of antibiotics such as penicillin, streptomycin or gentamycin, under the lining of the affected eyelids is recommended in herd outbreaks where repeated treatments are impractical. Often one injection is sufficient, but the treatment will need to be repeated in three or four days for severe or advanced cases of pinkeye. An intramuscular treatment is generally not recommended because very high dosages of an antibiotic are required to ensure adequate levels of the drug reach the eyes and tear glands.