The study of paraneoplastic syndromes in humans has a long history, whereas for domestic animals – only since the beginning of the 21th century. There are various forms of paraneoplastic syndromes; many classifications based on pathogenetic, organ-system principles are described. In accordance with the modern classification, paraneoplastic syndromes are divided into endocrinopathies, hematological paraneoplastic syndromes, gastrointestinal, renal, dermatological, neurological, ophthalmological. The purpose of this study was to develop a scientifically based algorithm for diagnosing ophthalmopathies against the background of paraneoplastic syndrome in dogs, including a multifactorial system of “hormonal-drug treatment” of paraneoplastic ophthalmopathies. The work used a comprehensive methodological approach, including the collection of anamnestic data, clinical examination of the animal, examination of the area of the pathological process, hematological studies, cytomorphological studies, visual diagnostic methods with complete oncological and ophthalmological examinations using the necessary equipment. Treatment for cancer included surgical removal of the tumor, chemotherapy and radiotherapy. The choice of treatment protocol depended on the location of the disease, tumor phenotype (if present) and stage of the malignancy. The only chemotherapy was applied using complex protocols in the treatment of dog lymphomas. Treatment of melanoma in dogs was carried out using an integrated approach which combined methods of surgery, chemotherapy, and radiotherapy. The obtained results can be recommended for use in the diagnosis and treatment of paraneoplastic ophthalmopathies in dogs.