• Korean Journal of Veterinary Service
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• v.43 no.4
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• pp.245-250
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• 2020

Infectious bovine keratoconjunctivitis (IBK) is the most common ocular disease in cattle, manifesting as corneal opacity, corneal ulcerations and potentially vision loss. The present report describes a 10-month-old Holstein Friesian heifer with IBK treated by systemic tulathromycin, and subconjunctival injection of penicillin and dexamethasone. We investigated changes in the hematological indices and microorganisms related to IBK after treatment. Neutrophils and monocytes decreased during recovery, so it was assumed that these two types of white cells are associated with IBK. Moraxella bovoculi was cleared in the eye, nasal cavity, and oral cavity after treatment. The distribution of M. bovoculi before treatment indicated that a combined systemic and subconjunctival treatment was necessary. The lesioned eye was found to be overwhelmed by Mycoplasma bovoculi, while pathogen abundance was reduced in the nasal cavity and oral cavities. These results suggest that antibiotic treatment can alter the composition and relative abundance of microorganisms.

• Journal of Pharmaceutical Investigation
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• v.22 no.3
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• pp.35-47
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• 1992

Hydrogel coated ring shaped ocular inserts (containing the antibiotic, tylosin tartrate) were used in an evaluation of the effectiveness of polymeric ocular drug release devices for treating infectious bovine keratoconjunctivitis. The in vivo experiments represent the first experiments using hydrogel ocular inserts containing an antibiotic for treating infectious bovine keratoconjunctivitis. In the infection tests, ten calves. were challenged with $2.4{\times}10^8{\sim}1.6{\times}10^9$ Moraxella bovis (a bacterium) colonies per eye following two ten minute ultraviolet radiation eye preconditioning exposures. Ninety five percent of the eyes (19 of 20 eyes) were successfully infected by this method. All infected eyes were monitored for the presence of the bacteria quantitiatively, and clinical observations were made for 14 days. The test was performed by three consecutive steps: 1) inoculation with 2 ultraviolet (UV) radiations, 2) growth of bacterial colonies and 3) treatment with medicated ring-shaped devices. The first. bacteriological measurements after 2 UV exposures were performed at day 3 of the tests. At day 7 after inoculation of both eyes of a calf with M. bovis, a medicated or a non-medicated ring-shaped device was inserted into each eye of a calf. The eye receiving the non-medicated ring was taken as a control for comparison with the eye that received a medicated ring. During the next 7 day period following a medicated ring insertion, the number of bacteria in the treated eyes dropped dramatically to negligible levels (0 to 30 colony forming units/swab), while the control eyes which received a non-medicated ring still exhibited a relatively high number of bacteria ($10^3\;to\;10^6$ colony forming units/swab). The number of bacteria was significantly reduced by the antibiotic released from the medicated ocular insert.

• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.53-59
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• 1985

A group of 80 Holstein calves, many with clinical signs of infectious bovine keratoconjunctivitis in summer seasons, was assembled for bacteriologic and ophthalmologic studies at an integrated dairy farm. Observations were started from 1980 to 1984 but bacteriological study was only carried out from thor spring in 1981 and continued during the Autumn in 1981. Corneal lesions and drugs sensitivity were also observed and the results obtained were as follows: 1. Occurrences of IBK-affected cattle during the 5 years were predominent to calves in summer. 2. Among 142 eyes from 80 cattle, 53 isolates of Moraxella bovis(37.3%) were isolated from 37 cattle(46.3%). The prevalence of the infection for clinical eyes were higher than nonclinical eyes calves. 3. Miscellaneous organisms were found from age groups of 5 months to 9 months old. It were 8 hemolytic Neisseria spp., 3 Fungi, Mycoplasma sp. and 1 Pseudomonas sp., but 9 samples were unknown. 4. Prevalence of infection with M. bovis in bilateral clinical eyes were higher than unilateral eyes. 5. Incidence of corneal lesion was predominent in early stage as a watery tears(21.0%) and late stage as a leukomas of corneal opacity(22.8%). 6. The number of isolations of M. bovis and incidence of IBK varied from year to year; Higher incidence of IBK clinical signs were showed in calves from 5 months to 10 months old and the number of isolations of M. bovis was declined in order 8 months(100.0%), 4 months(75.0%), 5 months(66.6%) and 8 months(66.6%) old calves. 7. Chloramphenicol, Nitrofurantoin and Cephalothin were highly sensitive against M. bovis isolates and then Tetracycline, Neomycin, Erythromycin and Kanamycin were intermediate but low sensitive to Streptomycin, Colistin and Penicillin.