Malignant catarrhal fever in cattle with suspected bracken poisoning

摘要

We would like to report an out-break of malignant catarrhal fever (MCF) in beef suckler cattle which also had evidence of bracken poisoning. At the time of the outbreak in August 2001, 85 Aberdeen Angus cross cows and youngstock had been co-grazingcontinuously with 300 Welsh mountain ewes and their lambs, lambing having occurred throughout the month of April. Grass growth had been poor from May to August and bracken fern, which was abundant, may have been consumed. On August 10,2001, three yearlings (A, B and C) were presented with pyrexia, each having a temperature of 41.6 deg C, serous to mucopurulent nasal discharge, salivation, and ulceration of the muzzle and oral mucosa. Within the next seven days, a further two yearlings (D and E) and a cow (F) developed similar clinical signs. Additional clinical signs included bilateral conjunctival petechial haemorrhages in yearling C and bilateral epistaxis in yearling E. All cases were treated by intravenous administration of an oxytetracycline preparation followed by intramuscular treatment with a long-acting oxvtetracvcline preparation the next day.