Hyperplastic and Inflammatory Nodules in the Canine Mammary Gland2

Techniques developed for demonstrating hyperplastic lesions in mammary glands of rodents were applied to whole mammary glands of untreated female beagle dogs. Any unusual structural change, as compared to the normal lobularity of the mammary gland, was considered an atypical nodule. Such nodules were classified histologically as normal, inflammatory, or proliferative. Evaluation of the mammary gland of the dog by the techniques described could substantially shorten the time required and improve the accuracy of oncologicand drug evaluation studies.