An outbreak of ringworm in a group of young cattle

In an outbreak of ringworm, 30 out of 32 bull calves being reared intensively for beef showed infection. Weekly observations were made from their arrival at the farm at about one week old until slaughter at approximately 10 1/2 to 12 months of age. The outbreak lasted for 33 weeks and appeared to originate from two animals brought into the unit. Lesions occurred first, and most commonly, in the head region. The disease in individual animals lasted eight weeks and each lesion had a mean duration of 3.6 weeks. New lesions occurred after those elsewhere on the same animal had healed. The mean incubation period was estimated at 4.6 weeks. Spread of ringworm was probably mainly due to the licking and grooming activities of the calves' tongues.