The Treatment of Infectious Bovine Keratoconjunctivitis Under Field Conditions: Intrapalpebral Injection Versus Subconjunctival Injection of Oxytetracycline

The purpose of this study was to determine the efficacy of oxytetracycline when applied intrapalpebral (IPa) injection to the eye, compared with subconjunctival (SCo) injection, in the treatment of infectious bovine keratoconjunctivitis (IBK). Twenty eyes with severe clinical signs of IBK, of 15 Holstein Friesian female cattle aged 2–4 years were evaluated in this study. The affected animals had unilateral (n=10; 66.7%) and bilateral (n=5; 33.3%) symptoms. Moraxella bovis were identified in all ocular swabs samples on day 0 and all isolates were susceptible to oxytetracycline (100%). Oxytetracycline (100 mg/ml) was injected IPa (n=10) and SCo (n=10) at a total dose of 200 mg once daily on days 0, 3 and 6. After injections, the animals were re-examined for resolution of lesions associated with IBK weekly until the corneal ulcer healed. Microbiologic examination was repeated 3 times at intervals of 1 week. There is no effect of injection type on healing time of the lesion. Size and side of the lesion have a significant effect on healing time (p<0.001). It was found that small lesions had earlier clean in terms of the microbiologic evaluation. Lesion size has a significant effect on microbial growth (p<0.001). In conclusion, the same therapeutic effect was achieved in both applications. However, oxytetracycline given by IPa injection was comparatively easy, more comfortable and less invasive especially for painful eyes against IBK than SCo injection under the conditions of this study. In addition, it was enough for cattle with IBK at the dosage (200 mg, once daily on days 0, 3 and 6) of used in the study