Intraocular Chondrosarcoma in a Rabbit.

Post-traumatic intraocular sarcomas are rarely reported in domestic animals and are most common in cats. An 8-year-old rabbit (Oryctolagus cuniculus) was referred to a veterinary clinic due to ocular discharge, uveitis and protein precipitate in the anterior chamber of the right eye. The eye was enucleated and histopathological examination revealed a poorly demarcated tumour within the ciliary body with invasion to adjacent eye structures. Neoplastic cells formed chaotic cartilage lacunae and were immunopositive for vimentin but immunonegative for pancytokeratin. On this basis, the neoplasm was diagnosed as a chondrosarcoma. To the best of our knowledge, this is the first report of intraocular chondrosarcoma in a rabbit. There was no history of previous ocular trauma but as there was serological evidence of Encephalitozoon cuniculi infection, inflammation could have been a predisposing factor to development of the neoplasm.

Canine and Feline Oral Cavity Tumours and Tumour-like Lesions: a Retrospective Study of 486 Cases (2015-2017).

Oral cavity tumours and tumour-like lesions are common in dogs and cats, and their diagnosis and classification requires histopathological examination. The aim of this study was to analyse retrospectively oral cavity lesions in dogs and cats in order to evaluate the distribution of inflammatory, hyperplastic and neoplastic lesions manifested as tumours. A total of 486 oral cavity tumours and tumour-like lesions (340 canine; 146 feline), diagnosed routinely from 2015 to 2017, were included. The lesions were classified as inflammatory, hyperplastic or neoplastic (benign and malignant). Histopathological diagnosis was based on haematoxylin and eosin staining and, when necessary, May-Grünwald-Giemsa (for mast cell tumours) or Masson's Fontana (for melanomas) stains or immunohistochemistry (for CD3, CD79α and S100 markers). For dogs, 29.11% (99/340) of the lesions were benign tumours, 24.12% (82/340) were hyperplastic lesions and 14.7% (50/340) were inflammatory lesions. For cats, 4.79% (7/146) were benign tumours, 15.07% (22/146) were hyperplastic lesions and 57.53% (84/146) were inflammatory lesions. Furthermore, 23.24% (79/340) of canine cases were diagnosed with gingival hyperplasia and 19.12% (65/340) were diagnosed with peripheral odontogenic fibroma, while 43.84% (64/146) of feline cases were diagnosed with chronic lymphoplasmacytic stomatitis. Malignant tumours in dogs and cats constituted 32.06% (109/340) and 21.91% (32/146) of the lesions, respectively, with high-grade melanoma in dogs and squamous cell carcinoma in cats being the most common.

Influence of simvastatin on hepatocytes - histopathological and immunohistochemical study.

The present study was undertaken to highlight the influence of simvastatin administration on hepatocyte morphology, proliferation, and apoptosis. The study included 48 gilts aged 3 months (weighing ca. 30 kg) divided into groups I (control; n=24) and II, receiving 40 mg/animal simvastatin orally (simavastatin; n=24) for 29 days. The animals were euthanized on days subsequent to the experiment. The livers were sampled, fixed, and processed routinely for histopathology, histochemistry, and immunohistochemistry (for proliferating cell nuclear antigen, Bcl-2, and caspase-3). Apoptosis was visualized by terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL). Simvastatin administration caused acute hepatocyte swelling, glycogen depletion, hyperaemia, multifocal hepatocyte proliferation with occasional pseudoacinar formation, connective tissue hyperplasia, eosinophil infiltration, and interface hepatitis. The proliferating cell nuclear antigen index, mean diameter of argyrophilic nucleolar organizer regions, and Bcl-2 immunoexpression were lower compared to control, and mean caspase-3 immunoexpression was higher in group II compared to control. On day 25 and 29 single hepatocytes in the simvastatin- treated group were TUNEL-positive. Simvastatin caused morphological alteration which became more intense over time. The results from the present study suggest that simvastatin treatment may cause glycogen, lipid metabolism and cell membrane permeability distortion, fibrosis, interface hepatitis, reduction in hepatocyte proliferation and transcriptional activity, and enhanced vulnerability to apoptosis. Summing up the results, it can be concluded that simvastatin caused liver damage with similar morphological changes seen in autoimmune-like liver injury, which may indicate that simvastatin may induce autoimmune-like drug induced liver injury.

Effect of feed supplementation with kynurenic acid on the morphology of the liver, kidney and gills in rainbow trout (Oncorhynchus mykiss Walbaum, 1792), healthy and experimentally infected with Yersinia ruckeri.

Kynurenic acid (KYNA) is an endogenous substance produced on the kynurenine pathway which is primarily known for its neuroactive properties. Recently, it has been proven that KYNA is a selective ligand for G protein-coupled receptor (GPR 35), presented on immunocompetent cells such as T lymphocytes. This opens up new possibilities of its application as an immunostimulating substance in aquaculture. Thus far, no histopathological investigations in fish have been completed to evaluate influence of KYNA supplementation in feed. This study has been undertaken to determine the effect of feed supplementation with KYNA (2.5, 25, 250 mg kg-1 of feed) for 28 days on the liver, gills and kidney in healthy fish and experimentally infected with Yersinia ruckeri. In a control group were observed a fatty liver, which is natural for this fish species in the autumn and winter season. As the dose of the supplement was increased, the fat liver changed, it decreased or completely disappeared. Additionally, inflammatory changes occurred in all the analysed organs, and their intensification was dose dependent. In the fish experimentally infected, KYNA caused aggravation of the signs in the liver, kidneys and gills, and the effect was dose dependent. The results implicate that KYNA may be a stressor for fish.

Morphology and immunoreactivity of canine and feline extramedullary plasmacytomas.

The aim of the study was the evaluation of morphology and immunophenotype of canine (19 cases) and feline (7 cases) extramedullary plasmacytomas. Tumours, located in skin, oral cavity and spleen were surgically excised, fixed and processed for histopathology and immunohistochemistry (CD79α, CD18, proliferating cell nuclear antigen, metallothionein). Histologically, tumours were classified into mature, cleaved, asynchronous, polymorphous blastic, hyalin, or monomorphous blastic type. All evaluated tumours showed cytoplasmic expression of CD79α antigen. The expression of CD18 was observed in canine cutaneous and splenic tumours. In canine tumours expression of metallothionein was low to moderate, while in feline plasmacytomas - absent or low. In canine tumours, the mitotic index and proliferating cell nuclear antigen index were positively correlated with the expression of metallothionein. In feline tumours no correlation between mitotic index, proliferating cell nuclear antigen and metallothionein was found. This is the first study describing expression of metallothionein in canine and feline extramedullary plasmacytoma.

Safety of the long-term application of QuikClot Combat Gauze, ChitoGauze PRO and Celox Gauze in a femoral artery injury model in swine - a preliminary study.

The purpose of this study was to examine the safety of the long-term application of QuikClot Combat Gauze, ChitoGauze PRO and Celox Gauze using a swine model. The study was conducted on nine pigs weighing approximately 30 kg, which were randomly divided into three groups. Under deep anesthesia, the pigs underwent complete transverse cutting of the femoral artery in the groin region. Hemostatic dressings were left in the wound for 24 hours. The animals were euthanized 24 hours after dressing application. In each group, macroscopic and microscopic severe changes and shock symptoms were observed in the lungs, liver, kidneys and heart. Fibrino-gaseous embolic material was found in the pulmonary artery of each group and in the lung vessels of the animals from the ChitoGauze PRO and Celox Gauze groups. In conclusion, the long-term application of the evaluated hemostatic dressings has the risk of coagulopathy and reaching the progressive stage of shock. The residues from the hemostatic dressings can ingress into the systemic circulation, thereby increasing the risk of embolus formation. Because of these harmful effects, the evaluated hemostatic dressings are not appropriate for long-term use. Future studies are needed on the consequences of the long-term application of these hemostatic agents.

Histopathological studies of the heart in three lines of broiler chickens.

The aim of this study was to analyse the morphological lesion pattern of the heart of broiler chickens (Cobb 500, Hubbard F15 and Ross 308) during fattening with no clinical signs of disease and to determine the most susceptible period for the occurrence of morphological lesions. The most frequently diagnosed lesions in each genetic line were degeneration of the fibres with vacuolation, congestion of cardiac muscle, oedema and vacuolisation of the Purkinje cells. The highest numbers of morphological lesions were observed on d 38, 31 and 10 of life. The lesions were most numerous in the septum, followed by the left and right ventricles. Ischaemic cardiomyocytes were also most numerous on d 38 of life and in the left ventricle. Overload of cardiac muscle, prolonged hypoxia and increasing body weight on d 38 are the likely reasons for the largest number of lesions and ischaemic fibres, which may lead to heart failure.

Effect of low-energy laser irradiation and antioxidant supplementation on cell apoptosis during skeletal muscle post-injury regeneration in pigs.

The aim of this study was to evaluate the effect of low-energy laser irradiation, coenzyme Q10 and vitamin E supplementation on the apoptosis of macrophages and muscle precursor cells during skeletal muscle regeneration after bupivacaine-induced injury. The experiment was conducted on 75 gilts, divided into 5 experimental groups: I--control, II--low-energy laser irradiation, III--coenzyme Q10, IV--coenzyme Q10 and vitamin E, V--vitamin E. Muscle necrosis was induced by injection of 0.5% bupivacaine hydrochloride. The animals were euthanized on subsequent days after injury. Samples were formalin fixed and processed routinely for histopathology. Apoptosis was detected using the TUNEL method. The obtained results indicate that low-energy laser irradiation has a beneficial effect on macrophages and muscle precursor cell activity during muscle post-injury regeneration and protects these cells against apoptosis. Vitamin E has a slightly lower protective effect, limited mainly to the macrophages. Coenzyme Q10 co-supplemented with vitamin E increases the activity of macrophages and muscle precursor cells, myotube and young muscle formation. Importantly, muscle precursor cells seem to be more sensitive to apoptosis than macrophages in the environment of regenerating damaged muscle.

Aggressive, solid variant of alveolar rhabdomyosarcoma with cutaneous involvement in a juvenile labrador retriever.

An 8.5-month-old male Labrador retriever presented with a cutaneous mass in the right maxillofacial region and swelling of the gingiva. The dog received antibiotic and anti-inflammatory treatment. After 3 weeks the dog returned, presenting with disseminated cutaneous tumours on the neck, trunk and groin. One of the nodules was resected and a cutaneous round cell tumour was diagnosed on microscopical examination. The dog was humanely destroyed. Necropsy examination revealed disseminated tumours in the skin, internal organs and skeletal muscles. Microscopically, all of the tumours were composed of small round cells, arranged in nests. Immunohistochemically, the neoplastic cells expressed vimentin, desmin, MyoD1, myogenin and smooth muscle actin, but were negative for CD3, CD18, CD79αcy, cytokeratin AE1/AE3, chromogranin A, class II molecules of the major histocompatibility complex, neuron-specific enolase and S100. The average Ki67 index was 89.5%. The final diagnosis was a solid variant of alveolar rhabdomyosarcoma (ARMS). This is the first report of the cutaneous multifocal form of ARMS in veterinary oncology.