Transmissible venereal tumor (TVT) is a transmissible cancer that typically affects the external genital organs in canines. It can spread to other parts of the body via auto- and hetero-transplantation in a way that neoplastic cells are inoculated into the degraded mucosa or skin during the interaction of the animals, such as licking and sniffing, or less commonly via hematogenous or lymphatic routes. Here, we presented the clinical, cytological, and histopathological characteristics of two rare cases of TVT that developed ocular involvement and were associated with a poor prognosis. Fine needle aspiration biopsy was the initial method of choice in the diagnosis which is rapid, minimally invasive, and effective. It was diagnostic in one case and aided in the diagnosis in the other. The latter was considered a malignant round cell tumor in the cytological examination that needed further clinical and histopathological examination for definitive diagnosis. TVT is a round cell tumor that should be considered in the differential diagnosis of ocular lesions in canines.