This study had the objective of elucidating factors involved in the causation of canine transmissible venereal tumour. Five hundred and two dogs brought to the animal clinic at Sokoine University of Agriculture were examined. Clinical examination and exfoliative cytology were used to distinguish dogs with ( n = 173) and without ( n = 329) the disease. Comparison was made between diseased and non-diseased dogs in terms of age, breed, sex, type of dog (use), and other extrinsic factors related to location and management. Management methods that allowed dogs to be in contact with each other predisposed them to the disease. Thus, guard dogs were noted to be at a higher risk of the disease than pets (odds ratio (OR) = 4.46). Dogs kept in high-density areas and in areas with high populations of stray dogs were more likely to contract canine transmissible venereal tumour compared to those raised in low-density areas and areas relatively free from stray dogs (OR = 6.13 and 6.78, respectively). It was concluded that management practices that allow unsupervised contact between dogs are among the important risk factors for canine transmissible venereal tumour.