Melanomas in horses are most often associated with gray, older horses with an average age of over 16 years. Anaplastic malignant melanoma, however, can very rarely affect non-gray horses. Herein, we report a case of a 16-year-old Wielkopolski gelding with a chronic lameness caused by a mass in the hoof. The first resection of the lesion and histopathological examination confirmed the presence of a keratoma. The regrown mass and persistent lameness resulted in another mass resection. The second histopathological examination result suggested a neoplastic growth of melanocytic origin with a low histological malignancy. Less than 2 years after the first resection, the horse returned to the clinic with deformation of the hoof capsule and severe lameness. The result of the third histopathological examination indicated low-differentiated malignant neoplasm. The result of the immunohistochemically test indicates a tumor of melanocytic origin with high malignancy.

Background and Aim: Centroblastic lymphoma (CBL) is the most common morphological type of lymphoma found in dogs; it is usually identified through cytology in veterinary clinical practice. This study aimed to identify the demographic and clinical characteristics of dogs with CBL that was diagnosed with cytology and immunocytochemistry. Materials and Methods: Dogs with a suspicion of lymphoma were diagnosed by cytology supported by immunocytochemistry with the use of the updated Kiel classification adapted for dogs. During the analyzed time period, 336 lymphomas were diagnosed in dogs, including 171 cases of CBL. Epidemiological and clinical data from the dogs with CBL were provisionally collected. Results: The epidemiology analysis revealed an increased risk of CBL in Rottweilers, golden retrievers, and Bernese mountain dogs. At admission, most of the dogs displayed generalized lymphadenopathy with spleen and liver enlargement. The most common hematological abnormality was leukocytosis due to neutrophilia. The most common biochemical abnormality was elevated alanine aminotransferase and alkaline phosphatase activities and selective hypoproteinemia due to hypoalbuminemia. Conclusion: Rottweilers, Bernese mountain dogs, and golden retrievers appear to be overrepresented among dogs with CBL. CBL is usually diagnosed at an advanced clinical stage according to the World Health Organization; however, it is usually accompanied by only minor hematological and biochemical abnormalities.

Centroblastic lymphoma (CBL) is the most common type of lymphoma in dogs and it usually responds well to chemotherapy. The aim of the study was to provide useful prognostic factors for dogs with CBL. Data regarding sex, breed, age, signalment, treatment and clinical course of the disease from 52 dogs diagnosed with centroblastic lymphoma (CBL) with cytology and immunocytochemistry were provisionally collected and related to the treatment outcome and survival. More than 80% of dogs were treated with chemotherapy and achieved complete remission in 80% of cases. Among the prognostic factors positively related to the overall survival time of dogs with CBL were: the application of chemotherapy, achieving a complete remission, application of at least one additional chemotherapeutic agent to the basic protocol, especially the administration of mitoxantrone and asparaginase. Moreover, mitotic count 14 or higher measured in cytological slides in the area of 2,37 mm2 have been linked to shorter overall survival in dogs with CBL.

The aim of the present study was to analyse epidemiological, cytological, laboratory and clinical data from canine acute leukemia (AL) cases. The study was conducted from 2009 to 2015, and included 2384 dogs undergoing cytological examination in two veterinary practices in Warsaw. The analysis included dogs in which bone marrow cytology revealed acute leukemia, regardless of its subtype. Data on breed, age, sex, as well as clinical signs and results of haematological examination were collected for every dog. Breed predisposition to acute leukemia was calculated by statistical methods on the basis of the theoretical distribution of canine breeds in Poland. Acute leukemia was diagnosed in 31 dogs (24.7%) undergoing bone marrow cytology, that is, in 1.3% of all the dogs examined by cytology during the study period. The disease was diagnosed mainly in adults, and a strong predisposition was found particularly in German shepherds and Golden retrievers. The median duration of clinical signs from the onset to diagnosis was 14 days. The clinical signs were mostly non-specific (apathy, recurrent fever, lack of appetite), whereas lymphadenomegaly or/and splenomegaly were observed more seldom. Hematology revealed neoplastic leukocytosis in 75% of dogs, whereas anemia and trombocytopenia were observed in 86% and 85% of patients, respectively. Regardless of the leukemia subtype, prognosis was poor. In conclusion, it can be stated that according to current knowledge on canine acute leukemias, bone marrow cytology based on routine staining methods is sufficient for correct diagnosis in a vast majority of cases.

A free-living yearling male brown bear (Ursus arctos) was observed in the wild, exhibiting marked ataxia, and died shortly after undergoing a standard immo