Cattle in upland areas of Scotland and northern England are substantially more prone to alimentary cancer than those of the immediately neighbouring lowlands, and epidemiological evidence implicates a combination of papilloma virus and bracken in the aetiology of the disease. Here Professor Jarrett outlines the circumstantial case against these agents and discusses its implications.

Danofloxacin is a new fluoroquinolone antibacterial, developed specifically for veterinary use. Its in vitro activity and pharmacokinetic properties have been investigated to assess its potential for use in the therapy of respiratory disease in cattle. The minimum inhibitory concentration of danofloxacin against 90% (MIC90) of contemporary European and North American field isolates of Pasteurella haemolytica, Pasteurella multocida and Haemophilus somnus, the most important bacterial respiratory pathogens of cattle, was 0.125 micrograms/ml. The plasma and lung kinetics of danofloxacin following parenteral administration of 1.25 mg/kg were evaluated in two studies. Danofloxacin was rapidly absorbed following intramuscular and subcutaneous injection and bioavailability was virtually complete (101% and 94% respectively). Plasma concentration profiles of danofloxacin were similar for intramuscular and subcutaneous routes with no significant differences in the area under the plasma concentration-time curves (AUC) following one, three or five consecutive daily doses, although slightly higher peak plasma concentrations were achieved by the intramuscular route. Following intramuscular administration, the mean peak lung concentration of danofloxacin was 4.1 times greater than that of plasma. Similarly, the AUC for lung tissue was 3.7 times greater than that for plasma. These data indicate that danofloxacin should be particularly appropriate for the therapy of bacterial respiratory disease in cattle.

The clinical features of 60 pathologically confirmed cases of bovine leucosis (lymphosarcoma) are described. The majority of cases could be classified into one of four distinct clinical forms, ie, juvenile multicentric, thymic, skin and adult multicentric. Diagnosis of leucosis in animals with these forms was possible on clinical grounds alone. Five animals, four of which were adult, could not be thus classified and diagnosis required haematological and, or, pathological examinations. The clinical, epidemiological and serological findings would suggest that the cases were examples of sporadic bovine leucosis.

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