Treatment of acute ocular Moraxella bovis infections in calves with a parenterally administered long-acting oxytetracycline formulation.
Acute ocular Moraxella bovis infections were induced in the UV-irradiated eyes of 10 calves. Eight calves developed corneal ulcers in at least 1 eye and were used for the treatment experiment. One randomly selected group of 4 calves with corneal ulcers and M bovis infections in 7 eyes was given a long-acting oxytetracycline formulation in 2 IM dosages of 20 mg/kg of body weight each, 72 hours apart. The other 4 calves with corneal ulcers in 6 eyes and M bovis in all 8 eyes served as nontreated controls. Bilateral ocular cultures were obtained and clinical observations were made daily for 20 days after treatment. After administration of the long-acting drug, new ulcers did not develop in the treated calves, whereas 5 new ulcers developed in the control-group calves during this time. The average durations of increased lacrimation/ulcerated eye were 2 and 12 days after treatment in the treatment and control groups, respectively; the average durations of blepharospasm were 3 and 8 days, respectively. Moraxella bovis was not isolated from any of the eyes of the treatment-group calves for the first 6 days after the antibiotic was administered, but was isolated from 1 eye of 1 treated calf on posttreatment day 7 and daily thereafter, for a total of 14 positive cultures of 160 ocular cultures obtained from the treatment-group calves after treatment. The bacterium was isolated from all eyes and from 144 of 160 cultures from the control-group calves during this time.
D000818:Animals; D001424:Bacterial Infections / Q000188:drug therapy / Q000662:veterinary*; D001764:Blepharospasm / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D003320:Corneal Ulcer / Q000188:drug therapy / Q000662:veterinary*; D003692:Delayed-Action Preparations; D005260:Female; D007637:Keratoconjunctivitis / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D009016:Moraxella; D010118:Oxytetracycline / Q000627:therapeutic use*; D013666:Tears / Q000378:metabolism
D003692:Delayed-Action Preparations; D010118:Oxytetracycline