Histologically confirmed inadequate treatment resulted in a lower than expected recurrence percentage in dogs with haemangiopericytoma (38%) and mastocytoma (30%). Clinical suspicion of inadequate tumour treatment did not always correlate with the histologically assessed inadequacy, nor with the appearance of local recurrence. Local recurrence did not seem to be correlated with histological grade of malignancy and tumour size. Local injection ofC. parvumvaccine did not result in a lower percentage of local recurrence or longer recurrence free intervals in any of the three tumour groups (canine haemangiopericytoma, canine mastocytoma, feline mammary carcinoma). Nor was palliative local adjuvant injection of Cp successful in dogs and cats with soft tissue sarcomas or in dogs with gingival melanoma. Re‐operation of locally recurrent tumour was successful in some dogs with haemangiopericytoma, in a few with mastocytoma, but not in cats with mammary carcinoma. A trend toward histological progression of recurrences and metastases, when compared with the primary tumours, was not evident. The possible reasons for the relatively low recurrence rate of some tumour types and for the failure of Cp‐treatment are discussed.