The field of veterinary oncology has advanced greatly over the last decade, and veterinarians have an important role in advising owners on whether and when certain treatments, such as radiotherapy, are indicated for dogs and cats. Using an online questionnaire (N=636), we investigated what treatment Austrian, Danish and UK veterinarians would recommend for a cat and a dog in a disease scenario where adjunctive radiotherapy would be optimal (a cat with a feline injection-site sarcoma and a dog with a soft tissue sarcoma). In both scenarios, around 40% of the veterinarians suggested radiotherapy, around 10% advised against it and around 27% did not make any recommendation. No significant differences were found in the advice given based on species. However, we identified that Danish veterinarians were significantly less likely to suggest radiotherapy compared to their UK and Austrian colleagues. Further, we found that veterinarians with additional qualifications or a greater interest in advancing veterinary medicine were more likely to recommend radiotherapy. Even though veterinarians would recommend radiotherapy for both species equally, the fact that approximately one quarter of veterinarians would not make any recommendation raises a potential ethical challenge since it may lead to different access of treatment for animal patients suffering from cancer.