Bacterial Conjunctivitis in Cattle and Antibiotic Sensitivity of the Isolates

A field study was carried out between June 2006 to July 2008, in order to determine the incidences of the pathogenic bacteria with its rule in conjunctivitis in cattle and the effective antibiotics for ocular administration. Three hundred- fifty cattle of different breeds, ages and sexes showing clinical signs of conjunctivitis were examined; 287 cattle were suffered from unilateral conjunctivitis (82%) and 63 cattle were suffered from bilateral conjunctivitis (18%). Conjunctival swabs from both eyes of 350 cattle were sampled; a total of 169 were bacteriologically positive (48%).Young cattle below 1 year old were significantly more susceptible to bacterial conjunctivitis than older (p value 0.002). Bacteria were isolated from 217 of total 700 conjunctival swabs (31%). Streptococcus sp. were the predominant bacteria isolated, 98 (31.3%); then Staphylococcus sp., 73 (23.3%), while Moraxella sp., Escherichia coli were the predominant gram negative bacteria isolated (12.1, 10% respectively). Isolated Staphylococcus sp. was highly resistant to antibiotics. Danofloxacin, lincomycin, enrofloxacin, gentamicin, erythromycin and kanamycin were effective whereas amoxicillin/clavulanic acid, ampicillin/sulbactam and oxytetracycline were moderately effective on most of the isolates. Most isolated bacteria were resistant to sulpha/Trimethoprim, chloramphenicol and Cefuroxime.