Abstract
Canine transmissible venereal tumor (CTVT) is a transmissible cancer that affects the external genitalia of dogs. In this study, a female canine with CTVT in the vagina was treated with vincristine (0.75 mg/m2; intravenous (IV); weekly for eight cycles), the currently preferred drug for CTVT, but without any progress. Therefore, this case was considered resistant to vincristine, and the preferred alternative chemotherapy, doxorubicin, was suggested. However, based on echocardiographic evidence, the patient could not be administered doxorubicin. Thus, the administration of lomustine was proposed. Although there are no studies to support this decision, the authors based their decision on the fact that lomustine is effective for round cell tumors, and that CTVT belongs to this tumor group. After three doses (60 mg/m2; every 3 weeks) complete remission was achieved. The use of lomustine at a dose of 60 mg/m2 every 3 weeks for vincristine-resistant CTVT proved to be effective, without any harmful side effects. The treatment is cost-effective and simple to manage.
Highlights
Canine transmissible venereal tumor (CTVT) is a transmissible neoplasm that affects the external genitalia of dogs (Ganguly et al, 2013)
Cytological examination provides better evidence of CTVT than biopsy due to the complex histological form of CTVT that differentiates it from other round cell tumors such as mast cell tumors, histiocytoma, and lymphosarcoma
Calvert et al (1982) reported a complete remission of CTVT in a dog after the administration of 30 mg/m2 of doxorubicin (IV) doses three times a week, which initially not respond to vincristine therapy. This drug is an antitumor antibiotic that inhibits DNA and RNA synthesis. In another retrospective study of 29 dogs with CTVT (Rogers et al, 1998), one of the patients had a partial response to vincristine; doxorubicin (30 mg/m2 IV; three times a week for five treatments) was administrated, which resulted in complete remission, but with recurrence after 2 months
Summary
Canine transmissible venereal tumor (CTVT) is a transmissible neoplasm that affects the external genitalia of dogs (Ganguly et al, 2013). Lomustine therapy for vincristine-resistant canine transmissible venereal tumor: a case report variable size. Vincristine sulfate is generally considered to be the most effective treatment for canine CTVT (Gonzalez et al, 2000; Martins et al, 2005; Nak et al, 2005; Scarpelli et al, 2010; Reis Filho et al, 2020); some tumors are resistant to this drug. The authors treated a vincristine-resistant case of CTVT with lomustine, an alkylating agent that inhibits the replication of tumor cells. The tumor was Lomustine therapy for vincristine-resistant canine transmissible venereal tumor: a case report nearing complete reduction; a third dose was administered for complete remission (Figure 5). The patient did not manifest any secondary effects to the medication and was tumor-free for 24 months after the treatment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
