Papillomavirus-induced dermatofibroma in cattle following tuberculin testing

Papillomavirus was identified in two fibromatous dermal nodules which were representative of those present in the caudal fold skin of the tail in 25 of 145 beef cattle tuberculin tested 3 months earlier. Bovine warts were endemic on the property and it is hypothesised that the papilloma virus was introduced intradermally by a virus-contaminated tuberculin syringe. At palpation, the well-circumscribed hard nodular lesions were atypical of the diffuse caudal fold swelling usually present in reactions to tuberculin. Provided tuberculin testing officers are aware of the risk of fibroma and papilloma induction by transmission of papillomavirus, and they are careful to prevent equipment coming into contact with warts at time of inoculation, this source of inaccuracy may be avoided.     

Papilloma-induced dermatofibroma in cattle following tuberculin testing

Papillomavirus was identified by avidin-biotin complex immunohistochemical testing of fibromatous nodules that developed in the caudal fold skin of the tail of two beef heifers. These tumours were representative of lesions identified in cattle tested, all of which had been tuberculin tested 3 months earlier. Bovine warts are endemic on the property and it is hypothesised that the papillomavirus was introduced intrader-mally by virus-contaminated vaccinal equipment.     

Papillomavirus-induced dermatofibroma in cattle following tuberculin testing

Papillomavirus was identified in two fibromatous dermal nodules which were representative of those present in the caudal fold skin of the tail in 25 of 145 beef cattle tuberculin tested 3 months earlier. Bovine warts were endemic on the property and it is hypothesised that the papilloma virus was introduced intradermally by a virus-contaminated tuberculin syringe. At palpation, the well-circumscribed hard nodular lesions were atypical of the diffuse caudal fold swelling usually present in reactions to tuberculin. Provided tuberculin testing officers are aware of the risk of fibroma and papilloma induction by transmission of papillomavirus, and they are careful to prevent equipment coming into contact with warts at time of inoculation, this source of inaccuracv mav be avoided.     

Evaluation of a number of ancillary tuberculin tests in cattle

Abstract

Extract

Two problems usually emerge when the incidence of bovine tuberculosis is reduced as a result of systematic tuberculin testing and removal of reactors. First, it is clear that certain organisms related to the bovine tubercle bacillus can induce tuberculin hypersensitivity resulting in many nonspecific responses to the tuberculin test. Examples of organisms that can give such reactions are those causing Johne's disease, avian tuberculosis, human tuberculosis, so-called “skin tuberculosis” and anonymous mycobacteria (Paterson, 1956 Paterson, A. B. 1956. The incidence and causes of tuberculin reactions in non-tuberculous cattle. Adv. Tuberc. Res., 7: 101–129.  [Google Scholar]). Secondly, in some herds tuberculosis is not eradicated despite repeated testing.