The Cancer is a life threatening ailment and has a reputation of being a silent killer. Neoplasms gained much importance in pet animals owing to the love and increased awareness among the people towards animal sufferings and pain. The diagnosis and management of neoplasms is one of the major challenges before veterinarians. The present manuscript describes the histopathological features of common canine cutaneous and mammary neoplasms. The correlation with the cell proliferative markers; mitotic index, AgNOR count, PCNA and Ki-67 indices and evaluation of these markers for their utility in tumour diagnosis.The book depicts and describes different histological lesions of skin tumours like histiocytoma, cavernous hemangioma,mast cell tumour , perianal gland adenoma , fibroma, fibromyxoma, basal cell carcinoma, squamous cell carcinoma, fibrosarcoma, myxosarcoma,perianal gland adenocarcinoma , liposarcoma, epidermoid carcinoma and sebaceous basal cell carcinoma. The different mammary tumours described are cystic fibroadenoma, benign mixed mammary tumour, papillary adenoma myoepithelioma, malignant mixed tumour, papillary adenocarcinoma, adenocarcinoma and solid carcinoma.