The aim of this study was to evaluate the impact of ovine infectious keratoconjunctivitis in a flock of Texel crossbred sheep on tropical pastures and the evolution of the disease under different oxytetracycline-based treatment protocols. Clinical signs observed in ewe lambs and ewes were conjunctivitis, photophobia, and epiphora, progressing to superficial to deep ulcerative keratitis. Experimental protocols are based on injectable oxytetracycline and flunixin, depending on the severity of the disease. A cost analysis of the disease control measure was conducted, considering the costs of sanitary inputs. To identify the etiological agent, samples of ocular secretion were collected from the affected animals. The etiologic agent identified was Mycoplasma conjunctivae. A total of 101 clinical observations were made on 23 ewe lambs, and 371 clinical observations were made on 65 ewes. The protocol of three consecutive injections of oxytetracycline every 72 hours was the most used for lambs and ewes during the outbreak. The cost of sanitary input for ewe lambs and ewes was US$ 73.62 and US$ 551.57, respectively. The recommendations described in this study are fundamental to reducing the impact of the disease on pasture sheep flocks and can be applied on farms to control outbreaks of infectious ovine keratoconjunctivitis.