The primary nasal canine transmissible venereal tumor (CTVT) is a rare disease that develops by the allografted transmission of neoplastic cells in the nasal cavity. The disease is uncommonly reported in free-roaming dogs, with the social behavior of excessive licking and vigorously sniffing the affected parts of the other dogs in an endemic population. Post-chemotherapeutic computed tomography (CT) scan features and correlation of vincristine sulfate with cellular phenotypes have been scarcely reported in previously available primary nasal CTVT studies. This study describes the radiographic, computed tomographic, and cellular phenotypic features in four dogs affected with stage-4 intranasal CTVTs. The post-chemotherapeutic features of the nasal cavity in fully recovered cases are also highlighted. All data were analyzed retrospectively. All four dogs had stage 4 modified Adam’s staging for nasal tumors due to the complete or partial lysis of the cribriform plate and lymphocytoid plasmacytoid (mixed) phenotype of the neoplastic cells based on the cellularity of cytological samples. All four dogs responded well to five cycles of vincristine sulfate and recovered completely. Two out of four dogs have follow-up scanning after chemotherapy. Based on the present study results, vincristine sulfate is still an effective monotherapy to achieve full recovery, although the number of cycles can vary, possibly depending on the expressed phenotype. Permanent loss of nasal turbinates is the sequelae of therapeutic chemotherapy. Prognosis is not correlated to the staging system but seems good with vincristine sulfate in mixed phenotype cases.

• Adams, W. M., Kleiter, M. M., Thrall, D. E., Klauer, J. M., Forrest, L. J., La Due, T. A., & Havighurst, T. C. (2009). Prognostic significance of tumor histology and computed tomographic staging for radiation treatment response of canine nasal tumors. Veterinary Radiology and Ultrasound, 50(3), 330–335. https://doi.org/10.1111/j.1740-8261.2009.01545.x

• Albanese, F., Poli, A., Millanta, F., & Abramo, F. (2002). Primary cutaneous extragenital canine transmissible venereal tumour with Leishmania-laden neoplastic cells: A further suggestion of histiocytic origin?. Veterinary Dermatology, 13(5), 243–246. https://doi.org/10.1046/j.1365-3164.2002.00301.x

• Bowles, K., DeSandre-Robinson, D., Kubicek, L., Lurie, D., Milner, R., & Boston, S. E. (2016). Outcome of definitive fractionated radiation followed by exenteration of the nasal cavity in dogs with sinonasal neoplasia: 16 cases. Veterinary and Comparative Oncology, 14(4), 350–360. https://doi.org/10.1111/vco.12115

• Brandão, C. V. S., Borges, A. G., Ranzani, J. J. Ti., Rahall, S. C., Teixeira, C. R., & Rocha, N. S. (2002). Transmissible venereal tumour in dogs: A retrospective study of 127 cases (1998-2000). Revista de Educação Continuada do CRMV-SP, 5, 25–31.

• Conte, F., Strack, A., Bastos-Pereira, A. L., & Pereira, M. L. (2022). Nasal transmissible venereal tumor (TVT) in dogs. Acta Scientiae Veterinariae, 50. https://doi.org/10.22456/1679-9216.117791

• Das, U., & Das, A. K. (2000). Review of canine transmissible venereal sarcoma. Veterinary Research Communications, 24(8), 545–556. https://doi.org/10.1023/A:1006491918910

• do Amaral, A. S., Bassani-Silva, S., Ferreira, I., da Fonseca, L. S., de Andrade, F. H. E., Gaspar, L. F. J., & Rocha, N. S. (2007). Caracterização citomorfológica do tumor venéreo transmissível canino [Cytomorphological characterization of transmissible canine venereal tumor]. Revista Portuguesa de Ciências Veterinárias, 102(563–564), 253–260.

• Foster, R. A. (2016). Male genital system. In M. Grant Maxie (Ed.), Jubb, Kennedy & Palmer’s pathology of domestic animals (6th ed., Vol. 3, pp. 465-510.e1). Elsevier. https://doi.org/10.1016/B978-0-7020-5319-1.00016-5

• Foster, R. A. (2017a). Female reproductive system and mammae. In J. F. Zachary (Ed.), Pathologic basis of veterinary disease (6th ed., pp. 1147-1193.e2). Elsevier. https://doi.org/10.1016/B978-0-323-35775-3.00018-7

• Foster, R. A. (2017b). Male reproductive system. In J. F. Zachary (Ed.), Pathologic basis of veterinary disease (6th ed., pp. 1194-1222.e1). Elsevier. https://doi.org/10.1016/B978-0-323-35775-3.00019-9

• Ganguly, B., Das, U., & Das, A. K. (2013). Canine transmissible venereal tumour: A review. Veterinary and Comparative Oncology, 14(1), 1–12. https://doi.org/10.1111/vco.12060

• Gimeno, E. J., Massone, A. R., Marino, F. P., & Idiart, J. R. (1995). Intermediate filament expression and lectin histochemical features of canine transmissible venereal tumour. APMIS, 103(7–8), 645–650. https://doi.org/10.1111/j.1699-0463.1995.tb01417.x

• Kabuusu, R. M., Stroup, D. F., & Fernandez, C. (2010). Risk factors and characteristics of canine transmissible venereal tumours in Grenada, West Indies. Veterinary and Comparative Oncology, 8(1), 50–55. https://doi.org/10.1111/j.1476-5829.2009.00204.x

• Komnenou, A. T., Thomas, A. L. N., Kyriazis, A. P., Poutahidis, T., & Papazoglou, L. G. (2015). Ocular manifestations of canine transmissible venereal tumour: A retrospective study of 25 cases in Greece. Veterinary Record, 176(20), 523–523. https://doi.org/10.1136/vr.102968

• Lawrence, J., Rohren, E., & Provenzale, J. (2010). PET/CT today and tomorrow in veterinary cancer diagnosis and monitoring: fundamentals, early results and future perspectives. Veterinary and Comparative Oncology, 8(3), 163–187. https://doi.org/10.1111/j.1476-5829.2010.00218.x

• Levy, E., Mylonakis, M. E., Saridomichelakis, M. N., Polizopoulou, Z. S., Psychogios, V., & Koutinas, A. F. (2006). Nasal and oral masses in a dog. Veterinary Clinical Pathology, 35(1), 115–118. https://doi.org/10.1111/j.1939-165X.2006.tb00100.x

• Mukaratirwa, S., & Gruys, E. (2003). Canine transmissible venereal tumour: Cytogenetic origin, immunophenotype, and immunobiology. A review. Veterinary Quarterly, 25(3), 101–111. https://doi.org/10.1080/01652176.2003.9695151

• Neer, T. M., Breitschwerdt, E. B., Greene, R. T., & Lappin, M. R. (2002). Consensus statement on ehrlichial disease of small animals from the infectious disease study group of the ACVIM. Journal of Veterinary Internal Medicine, 16(3), 309-315. https://doi.org/10.1111/j.1939-1676.2002.tb02374.x

• Nemzek, J. A., Lester, P. A., Wolfe, A. M., Dysko, R. C., & Myers, D. D. (2015). Biology and diseases of dogs. In J. G. Fox, G. M. Otto, M. T. Whary, L. C. Anderson, & K. R. Pritchett-Corning (Eds.), Laboratory animal medicine (3rd ed., pp. 511–554). Elsevier. https://doi.org/10.1016/B978-0-12-409527-4.00012-2

• Ojeda, J., Mieres, M., Soto, F., Arnes, V., Paredes, E., & Navarrete, M. (2018). Computer tomographic imaging in 4 dogs with primary nasal canine transmissible venereal tumor and differing cellular phenotype. Journal of Veterinary Internal Medicine, 32(3), 1172–1177. https://doi.org/10.1111/jvim.15125

• Papazoglou, L. G., Koutinas, A. F., Plevraki, A. G., & Tontis, D. (2001). Primary intranasal transmissible venereal tumour in the dog: A retrospective study of six spontaneous cases. Journal of Veterinary Medicine Series A, 48(7), 391–400. https://doi.org/10.1046/j.1439-0442.2001.00361.x

• Patsikas, M., Adamama-Moraitou, K., Thomas, A., Soultani, C., Chrissogonidis, I., Fotiadou, A., Trikoupi, G., Papadopoulou, P., Ilia, G., Kosmas, P., & Farmakis, P. (2018). Pre- and post-treatment computed tomographic findings of a primary intranasal transmissible venereal tumor in a canine patient. Journal of Biological Regulators and Homeostatic Agents, 32(3), 571–576.

• Raghunath, M., Chowdhary, R., Sagar, P. V., & Kumar, P. R. (2015). Genital and extra genital TVT in a bitch - A case report. The Indian Veterinary Journal, 91(5), 79-80.

• Rezaei, M., Azizi, S., Shahheidaripour, S., & Rostami, S. (2016). Primary oral and nasal transmissible venereal tumor in a mix-breed dog. Asian Pacific Journal of Tropical Biomedicine, 6(5), 443–445. https://doi.org/10.1016/j.apjtb.2016.03.006

• Robertson, J. F., Wilson, D., & Smith, W. J. (1990). Atrophic rhinitis: The influence of the aerial environment. Animal Science, 50(1), 173–182. https://doi.org/10.1017/S0003356100004578

• Rogers, K., Walker, M., & Dillon, H. (1998). Transmissible venereal tumor: A retrospective study of 29 cases. Journal of the American Animal Hospital Association, 34(6), 463–470. https://doi.org/10.5326/15473317-34-6-463

• Schuenemann, R., & Oechtering, G. (2014). Inside the brachycephalic nose: Conchal regrowth and mucosal contact points after laser-assisted turbinectomy. Journal of the American Animal Hospital Association, 50(4), 237–246. https://doi.org/10.5326/JAAHA-MS-6086

• Setthawongsin, C., Teewasutrakul, P., Techangamsuwan, S., & Rungsipipat, A. (2017). Cytomorphological study of canine transmissible venereal tumor. The Thai Journal of Veterinary Medicine Supplement, 47, 165–166.

• Strakova, A., & Murchison, E. P. (2014). The changing global distribution and prevalence of canine transmissible venereal tumour. BMC Veterinary Research, 10, 168. https://doi.org/10.1186/s12917-014-0168-9

• Sukhbir, R., & Sood, N. K. (2016). Management of primary transmissible venereal tumor in nasal cavity of a dog. Intas Polivet, 17(2), 546–548.

• Thamm, D. H. (2007). Miscellaneous tumors. In Withrow and MacEwen’s small animal clinical oncology (4th ed., pp. 785-823). Elsevier. https://doi.org/10.1016/B978-072160558-6.50035-6

• Tyagi, A., Arora, R., Ahmad, S. F., & Arora, N. (2018). Therapeutic management of transmissible venereal tumor in nasal cavity of a dog. Intas Polivet, 19(1), 160–161.

• Ujvari, B., Gatenby, R. A., & Thomas, F. (2017). Transmissible cancer: The evolution of interindividual metastasis. In Ecology and evolution of cancer (pp. 167–179). Elsevier. https://doi.org/10.1016/B978-0-12-804310-3.00012-0

• Veloso, J. F., de Andrade Oliveira, T. N., Andrade, L. P., Silva, F. L., Sampaio, K. M. O. R., Michel, A. F. R. M., de Lavor, M. S. L., & Carlos, R. S. A. (2018). Three cases of exclusively extragenital canine transmissible venereal tumor (cTVT). Acta Scientiae Veterinariae, 46, 8. https://doi.org/10.22456/1679-9216.86846