Clinical and pathomorphological changes in a cat during the course of post-vaccination sarcoma

Prevention of infectious diseases in cats is a guarantee of their health. It is important to carry out routine annual vaccination in cats to maintain a stable titer of antibodies in the cat's blood. However, due to the injection of vaccines into the same part of the body every time, the risk of such a dangerous malignant tumor in the area of injection as post-vaccination sarcoma increases. This pathology occurs in every 13–16th vaccinated cat per 10 thousand heads. The article describes a clinical case of post-vaccination sarcoma in cat. A comprehensive examination of the sick animal was carried out using various diagnostic methods. Clinical and ultrasonographic methods of visual diagnosis, hematological studies of blood and cytological studies of punctate from the tumor, as well as histological examination of the neoplasm after surgical removal of the tumor were used. It has been established that post-vaccination sarcoma looks like a diffuse, non-painful, non-hot swelling that is localized in the subcutaneous tissue. Ultrasonographically, the tumor has a heterogeneous structure and central-type vascularization with infiltrative growth. Hematological indicators of blood in a sick cat are characterized by reactive leukocytosis with a shift of the nucleus to the left and an increase in the sedimentation rate of erythrocytes up to 15 mm/h. While on the 10th day after surgical removal, these indicators decrease to normal. Cytological examination of the neoplasm showed the presence of atypical giant multinucleated cells with polymorphic nuclei in which a large number of mitoses and lymphoid cells occur. Histological changes in the tumor are represented by spindle-shaped tumor cells with strongly expressed atypism and pathological forms of mitosis in tumor cells. The stroma of the tumor is permeated with blood vessels, which indicates the progressive aggressive growth of the neoplasm.