Immunoreactivity of p21, MMP-1 and CB2 receptor proteins in cutaneous canine mast cell tumours: an association with the three-tier grading system.

Introduction: Mast cell tumours (MCTs) arise in the dermis and subcutaneous tissues in animals and humans and are one of the most common neoplasms of the skin in dogs. Cannabinoid type 2 receptor (CB2R), cyclin-dependent kinase inhibitor (p21) and matrix metalloproteinase 1 (MMP-1) are potential targets for novel anti-tumour therapeutic strategies. This study evaluated by immunohistochemical means the reactivity of p21, MMP-1 and CB2R proteins in association with a three-tier grading system in cutaneous canine MCTs. Material and Methods: Formalin-fixed, paraffin-embedded canine MCTs were processed for histochemical analysis and immunohistochemical staining using antibodies against p21, MMP-1 and CB2R. The results were analysed statistically. Results: The strongest p21 immunolabelling was detected in grade 3 MCTs, while grade 1 tumours showed mild or no detectable p21 immunoreactivity (P-value < 0.001). Strong immunolabelling of MMP-1 was the most common in grade 1 tumours (P-value < 0.001) and CB2R was significantly less frequent in grade 3 tumours than in grade 1 (P-value < 0.001) and grade 2 (P-value < 0.001). Conclusion: High immunoreactivity of MMP-1 can be a marker of grade 1 MCTs in dogs, whereas p21 protein overexpression can be a marker of grade 3 canine MCTs. Strong CB2R immunoreactivity with simultaneous underexpression of p21 and high immunoreactivity of MMP-1 proteins may indicate that the use of cannabinoids in grade 1 MCTs in dogs is practicable.

Incidence and the risk of occurrence of benign and malignant canine skin tumours in Poland - a five-year retrospective study.

Introduction: The aim of the study was to compile data on the frequency and distribution of canine skin tumours and determine the risk of these being malignant as opposed to benign. This determination proceeded from tumour histogenesis and gave consideration to the dog's breed, sex, age and the anatomical location of tumours. Material and Methods: This retrospective five-year epidemiological study included 3,139 canine skin tumours collected in Poland. A univariable logistic regression analysis was performed to determine the odds ratios (ORs) with 95% confidence intervals (CIs). Results: Microscopic analysis showed a significant predominance of benign tumours (65.02%) as well as mesenchymal and melanocytic tumours (59.57%). The most frequently diagnosed were mast cell tumours, accounting for 13.79% of all skin tumours, and other common tumour types were lipomas (6.40%), haemangiopericytomas (5.96%) and malignant melanomas (4.65%). The risk of malignant versus benign tumours was 1.212 times higher in the female than in the male dogs. A higher risk of development of malignant epithelial tumours was found in boxers (OR 4.091), German shepherds (OR 4.085) and flat-coated retrievers (OR 43.596). A higher risk of development of malignant mesenchymal tumours was found in golden retrievers (OR 4.693), boxers (OR 2.342), bulldogs (OR 3.469) and Maltese (OR 2.757). Conclusion: The results may serve as a reference point for further studies of the complex biology of canine skin tumours.

Topoisomerase IIα immunoexpression in feline mammary carcinomas: A correlation with Ki67 immunoexpression and the mitotic count.

The aim of the study was to compare the immunohistochemical expression of topoisomerase IIα protein (Topo IIα) with Ki67 expression and mitotic count in feline mammary carcinomas (FMCs). Topo IIα is considered as a proliferation indicator as well as a molecular target of anthracycline chemotherapy. The studied material included 70 FMCs from female cats treated with mastectomy. Primary mouse monoclonal antibodies directed against Topo IIα and Ki67 were used in immunohistochemical reactions. The number of mitotic figures was counted at 400× magnification in a field of 2.37 mm2. Immunohistochemical reaction for Topo IIα occurred in cell nuclei. The Topo IIα index ranged from 6.12% to 54.60% and was positively correlated with the values of the Ki67 index (r = 0.7193) and the mitotic count (r = 0. 2858). This indicates the potential possibility of use of the immunohistochemical expression of Topo IIα to assess the rate of proliferation in FMCs. The wide range of expression of Topo IIα in individual tumorus found in the conducted studies allows us to hypothesize that its assessment could be used as a predictive marker in chemotherapy of FMCs with the use of anthracyclines. However, this requires confirmation in clinical trials.

Pharmacological Treatment of Perianal Gland Tumors in Male Dogs.

The presence of androgen (AR) and estrogen (ER) receptors has been demonstrated both in normal perianal (hepatoid) glands and in perianal tumors. The aim of this study was to demonstrate the relationship between the expression of AR and ER in perianal gland tumors and the effectiveness of antihormonal treatment. The study was performed on 41 male dogs with neoplastic lesions of the anal region. Histopathological evaluation of the lesions revealed 24 adenomas, 12 epitheliomas, and five carcinomas. Treatment was administered orally with tamoxifen at a dose of 1 mg/kg BW and cyproterone acetate at a dose of 5 mg/kg. Tumor diameters were measured regularly with calipers and recorded in millimeters starting with the measurement before treatment, and then after 1, 2, 3, 6, 12, 18, and 24 months of therapy. The results show that hepatoid adenomas that are characterized by high expression of AR and ER receptors respond positively to antihormonal therapy, resulting in complete tumor regression. For locally malignant hepatoid epitheliomas and carcinomas with low expression of AR and ER receptors, antihormonal therapy makes it possible to reduce the size of the tumor, but does not make it possible to cure it completely.

Assessment of health safety of pigs taking natural sorbents with feed.

BACKGROUND: The study assessed the effect of smectites (bentonite and zeolite) used as natural sorbents in the diet of pigs on feed digestibility, health parameters, the severity of anatomo-histological changes in organs, and the accumulation of volatile pollutants in organs. MATERIAL AND METHODS: The study was conducted using fattening pigs (crossbreds from multiple breeds) assigned to three groups - a control (C) and two experimental groups (A and B), with 240 pigs in each group (3 replicates × 80). The animals in group C received a standard complete diet, while groups A and B received diets with 1.5% composed smectite sorbents. The feed and faeces were analysed for content of dry matter, crude ash, crude protein, ether extract, and crude fibre. The content of P was determined using a Helios Alpha UV-VIS spectrophotometer. Whole blood was analysed for haematological parameters and serum for biochemical parameters. Tissue samples were collected for analysis of volatile substances and histological analysis. After slaughter, samples of the lungs, liver, kidneys and jejunum were collected for morphological evaluation, and samples of the perirenal fat, liver, kidneys, lungs and brain for headspace gas chromatography (GC) to determine the levels of volatile toxic substances. RESULTS: A statistical increase in the digestibility of crude fibre and an increase in that of P were observed in both experimental groups (A and B) in comparison to the control. The whole blood and serum of the pigs from the control group had statistically significantly higher levels of creatinine, urea, and Mg and a higher WBC count compared to both experimental groups (A and B). CONCLUSIONS: The feed additives were not shown to have a negative effect on the health parameters analysed or on accumulation of pollutants in selected tissues. No significant effect on the digestibility of most nutrients was observed; only an increase in the digestibility of crude fibre and a decrease in P digestibility were noted in the experimental groups.

Evaluation of the Proliferative Activity of Diffuse Large B-Cell Lymphoma (DLBCL) in Dogs with Respect to Patient Eligibility for Anthracycline-Based Chemotherapy.

Different types of canine lymphoma respond differently to chemotherapy and have different prognoses. Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in dogs. Topoisomerase II alpha (TOPIIα) protein has been shown to be a proliferation marker associated with prognostic significance. The aim of the study was to determine the relationship between TOPIIα expression, mitotic count (MC), and Ki67 antigen index in DLBCL in dogs, taking into account the applicability of these parameters to select the chemotherapy protocol with emphasis on the use of anthracycline drugs. Samples of formalin-fixed paraffin-embedded lymph nodes from 34 dogs with DLBCL were immunohistochemically labelled with anti-TOPIIα and Ki67. The number of positive cells and the intensity of the reaction were taken into account in order to assess TOPIIα expression. MC was estimated in the hematoxylin and eosin-stained slides in the area of 2.37 mm2. Positive association between TOPIIα and MC, but no association between TOPIIα and Ki67 was found. It can be concluded that the immunohistochemical determination of TOPIIα as a molecular target for drugs from the anthracycline group may be used in association with MC to establish a diagnostic-clinical protocol for selecting dogs with DLBCL for treatment with anthracycline drugs.

Androgen and Estrogen Receptor Expression in Different Types of Perianal Gland Tumors in Male Dogs.

Perianal gland tumors are modified sebaceous glands present in the skin of the perianal region in the dog. Hormonal stimulation may induce hyperplasia of the perianal glands or their neoplastic progression. The presence of androgen (AR) and estrogen (ER) receptors have been demonstrated both in normal perianal glands as well as in perianal tumors. The aim of the study was an immunohistochemical assessment of the expression of estrogen and androgen receptors in perianal gland tumors in dogs as an applicatory marker for antihormonal treatment. Biopsy samples of perianal masses were collected from 41 male dogs. A histopathological examination revealed 24 adenomas, 12 epitheliomas and five carcinomas. The immunohistochemical staining showed a mainly nuclear expression of AR and ER in the neoplastic cells. Both the androgen and estrogen receptors were expressed in adenoma, epithelioma and carcinoma cases; however, the highest expression of the receptors was stated in the adenoma and epithelioma. In the case of the carcinoma, the expression of sex hormone receptors was very weak. The differences of the number of cells expressing AR and ER as well as the observed differentiated intensity of staining in the studies demonstrated that the determination of the expression of the sex hormone receptors may be useful to elaborate a diagnostic and therapeutic algorithm.

Aggressive squamous cell carcinoma of the cranium of a dog.

BACKGROUND: The authors report a case of keratinized squamous cell carcinoma (SCC) in a 14-year-old dog with extensive cranial bone invasion. To our knowledge, this is the first description of such a case of cranial keratinized SCC with aggressive generalized osteolysis described in a dog. CASE PRESENTATION: The 14-year-old dog was referred for radiological examination with suspicion of head trauma with clinical signs of head deformation, exophthalmos and nasal discharge. The skull radiographs showed a large osteolytic defect of the frontal bone and parietal bone in the region of the external sagittal crest. Findings from the skull CT scan included generalized osteolysis in the region of parietal bone, frontal bones, maxilla on the right side and the nasal bone including the dorsal nasal concha. In the area of bone loss, new soft tissue formation with multifocal foci of mineralization was visible. The ultrasound examination revealed hypoechogenic changes with hyperechoic foci consistent with mineralization and poor vascularization. The brain and ocular structures were without visible changes. Fine needle aspiration cytology (FNAC) was performed, and squamous cell carcinoma was suspected. After 3 months, the re-presented to the clinic. The dog became progressively listless, his appetite was decreased, and he became acutely blind. Follow-up skull CT scan revealed significant osteolysis, which affected a significant aspect of the cranium. All bone defects had been replaced by new 3.5 cm-thick soft tissue formations with multifocal small 1-2 mm areas of mineralization. There was no evidence of metastasis. Histological examination confirmed the suspicion of squamous cell carcinoma. CONCLUSIONS: This paper is the first report of cranial SCC in a dog causing extensive bone osteolysis. The lesions in this dog originated from the frontal and parietal bones including frontal sinuses. There are variants of tumors that arise from squamous epithelium or resemble SCC in the skull. These examples include adenosquamous carcinoma and proliferating trichilemmal tumours. In addition, there is possible malignant transformation caused by papilloma viruses. In the veterinary literature, there is only one similar description of adenosquamous carcinoma in a cat with similar clinical manifestations. It is justified to suspect a process of neoplastic epithelial origin in all cases of aggressive and extensive skull bone lysis. This issue should be subject to further investigation.

Mutations of p53 Gene in Canine Sweat Gland Carcinomas Probably Associated with UV Radiation.

INTRODUCTION: Apocrine sweat gland carcinomas (ASGCs) are rare malignant skin tumours in dogs and humans. The literature published so far focuses mostly on the clinico-epidemiological aspect of these tumours, but little is known about their pathogenesis. In this study we aimed to determine whether the p53 gene is involved in the carcinogenesis of the apocrine sweat gland in dogs and whether ultraviolet radiation (UV) is related to it. MATERIAL AND METHODS: Forty canine ASGCs were submitted to laser capture microdissection to isolate neoplastic cells, from which DNA was subsequently extracted. PCR amplification and sequencing of p53 exons 2-8 was then performed, followed by computer analysis of the obtained sequences. RESULTS: Sixteen mutations within the p53 gene were found in 13 tumours. The mutations involved C → T, T → C, G → A, and CC → TT transitions, C → G transversion and adenine deletion, which are gene alteration types known to be related to UV radiation in the process of skin carcinogenesis in humans. Six of the thirteen tumour cases displayed the C → T transitions in the same location in exon 4 and three of the thirteen cases displayed T → C in the same location in exon 5. CONCLUSION: The results of the present study indicate both the participation of the p53 gene and the influence of UV radiation in the formation of ASGCs in dogs.

Translocation of intestinal bacteria as a cause of subcutaneous abscesses of the neck and head in American mink (Neovison vison) - a case report.

BACKGROUND: The problem of transmission of intestinal microorganisms to tissues occurs when intestinal epithelial cells do not adhere tightly (tight junction), which is caused by improper nutrition, usually associated with poor mucosal status. The impact on maintaining its proper condition in the case of animals also depends on the proper preparation and fragmentation of the ingredients of the feed. Intestinal microbiota disorders are increasingly indicated as one of the causes of many autoimmune, neurodevelopmental and metabolic diseases. However, there are no studies indicating damage to the intestinal barrier of animals resulting in the penetration of microorganisms from the gastrointestinal tract directly into the bloodstream which may result in the development of chronic inflammation. CASE PRESENTATION: On a mink (Neovison vison) farm with a foundation stock of 4,000 females, abscesses were observed in the head, followed by progressive deaths. Antibiotic treatment with amoxicillin and clavulanic acid added to the animals' feed was not successful. Macroscopic and microscopic changes indicated local suppurative inflammation of the skin and subcutaneous tissue with the presence of purulent fistulas. Microbiological analysis showed a significant increase in Escherichia coli in all samples taken from the abscesses. The results indicate the migration of intestinal bacteria through disturbance of the permeability of the intestinal barrier and their transfer to the blood. Symptoms were alleviated in all animals following changes in the feed components and in feed particle size. CONCLUSIONS: It is necessary to take into account the possibility of transmission of intestinal bacteria in the etiology of inflammatory diseases in animals. Conducting more research in this field will improve the understanding of the relationship between intestinal microbes and the health of the body as a whole.

Study of DNA topoisomerase IIa expression in canine lymphomas and its potential role as a marker of sensitivity to anthracycline-based chemotherapy in dogs.

INTRODUCTION: Canine lymphoma remains one of the most chemotherapy-responsive neoplasia in dogs. Many factors affect the prognosis in dogs treated for lymphoma, but indications for a specific treatment regimen in individual animals with lymphoma are poorly defined. Topoisomerase IIα (TOPIIα) is a key enzyme in DNA replication and a molecular target for TOPIIα inhibitors, including anthracyclines. The aim of this study was to determine the expression of TOPIIα in canine malignant lymphomas. The relationship between TOPIIα expression in canine lymphomas and potential sensitivity of neoplastic cells to anthracycline-based chemotherapy is discussed. MATERIALS AND METHOD: Samples of formalin-fixed paraffin-embedded lymph nodes from 47 dogs with different subtypes of non-Hodgkin's (34 B-cell and 13 T-cell) lymphoma were immunohistochemically labeled with anti-TOPIIα. The number of positive cells and the intensity of the reaction were taken into account in order to assess TOPIIα expression. RESULTS: TOPIIα expression was evident in all cases, although differences in the number of positive cells and intensity of the reaction were demonstrated between B-cell and T-cell lymphoma groups as well as within individual groups. Based on the established scoring system, in the B-cell lymphoma group statistically higher expression of TOPIIα was found compared to the T-cell lymphoma group (P = 0.006). In B-cell lymphoma group moderate (41.18%) and strong (32.35%) TOPIIα expression predominated, whereas among T-cell lymphoma group the majority were cases with a weak (46.15%) TOPIIα expression. CONCLUSION: These preliminary results indicate that further studies are needed to determine the prognostic value of TOPIIα expression with regard to the sensitivity of canine B-cell lymphomas to anthracycline-based chemotherapy regimen. Nevertheless, this study indicates the possibility of choosing the appropriate treatment of canine lymphoma based on TOPIIa expression.

Decorin concentrations in canine normal and neoplastic mammary gland tissues.

In the present study, the concentration of decorin in canine normal and neoplastic mammary gland tissues was examined to understand the potential role of decorin in development and progression of canine mammary tumours. The homogenates of 48 mammary gland tumours (10 benign and 38 malignant) and 10 samples of normal canine mammary gland tissue were used in the study. The presence and quantification of decorin was examined in the homogenates using Western blot and specific canine ELISA. Western blotting confirmed the presence of decorin both in the normal mammary gland tissues and in the mammary gland tumours. The concentration of decorin was significantly higher (p < .05) in the benign tumours and non-metastatic malignant tumours than in the normal mammary gland. The concentration of decorin was significantly lower (p < .05) in the malignant tumours with metastasis to regional lymph nodes compared with benign tumours and non-metastatic malignant tumours. No significant differences were found in the level of decorin between the benign and the non-metastatic malignant tumours. Both the histological type of malignant tumours and the histological grade did not significantly affect the concentration of decorin. These findings suggest that neoplastic transformation in the canine mammary gland leads to increase in the decorin protein synthesis. The reducing decorin concentration in canine malignant mammary tumours appears to facilitate the metastatic spread of these tumours.

Granular Cell Tumor in a Horse: Multifocal Pulmonary Distribution and Evidence of Autophagy in Tumorigenesis.

Granular cell tumor (GCT) is a soft tissue neoplasm characterized by abundant intracellular eosinophilic granules. The majority of GCTs are benign, although some display malignant behavior. Furthermore, GCTs may mimic other neoplasms. The clinical course and biology of GCTs are poorly understood. Regarding the histogenesis of GCT, a Schwann cell origin is currently favored in light of immunohistochemical and ultrastructural analyses. However, based on literature data, some of the primitive GCTs show non-neural origin; therefore, the histogenesis of this tumor has remained enigmatic. Granular cell tumors can arise in almost any location of the body and typically present as solitary lesions. This study illustrates equine primary GCT with multifocal pulmonary distribution. The presence of GCT in the respiratory tract becomes a diagnostic challenge on initial presentation. The morphologic details of this case are presented. Immunohistochemical evaluation confirmed the neuronal origin of equine GCT and the relation of intracytoplasmic granules formation to an autophagy phenomenon. Most of the discussion is related to GCT nature to help characterize molecular aspects associated with the biological behavior of this tumor and its heterogeneity.

Occurrence and Distribution of Canine Cutaneous Mast Cell Tumour Characteristics Among Predisposed Breeds.

INTRODUCTION: Breed predisposition to cutaneous mast cell tumours (MCT) in a population of dogs in Poland affected by various skin tumours was assessed, and the distribution of MCT characteristics such as histological grading, sex, age, and location, in predisposed breeds was evaluated. MATERIAL AND METHODS: The retrospective epidemiological study included 550 dogs affected by cutaneous MCTs with a reference group of 2,557 dogs diagnosed with other skin tumours. RESULTS: A univariable logistic regression analysis was performed to determine the odds ratios (ORs) with 95% confidence intervals. The risk of high-grade MCTs was the highest for Shar-Peis (OR: 26.394) and American Staffordshire Terriers (OR: 2.897). Boxers (OR: 6.619), Labrador Retrievers (OR: 2.630), French Bulldogs (OR: 2.050), Golden Retrievers (OR: 1.949), and American Staffordshire Terriers (OR: 2.592) were mainly affected by low-grade MCTs. The high risk of MCT was calculated to be at the age of 4-6 years for Labrador Retrievers (OR: 2.686) and 7-10 years for Boxers (OR: 2.956) and French Bulldogs (OR: 9.429). MCTs were significantly more often located on the trunk in French Bulldogs (OR: 4.680), American Staffordshire Terriers (OR: 2.520), and Labrador Retrievers (OR: 1.948). There was no statistically significant correlation between gender and the occurrence of MCTs in the breeds. CONCLUSIONS: The breed-predicated differences in the clinical course of MCTs suggest a genetic background for the tumours.

Immunohistochemical expression of p63 protein and calponin in canine mammary tumours.

The aim of this study was to compare the expression of p63 protein and calponin in terms of their affinity and specificity for myoepithelial cells in canine mammary tumours. The studied material included 10 benign and 32 malignant mammary tumours from female dogs treated with mastectomy. Primary mouse monoclonal antibodies directed against p63 protein clone 4A4 and calponin clone CALP were used in single- and doublestain system of immunohistochemical reaction. The investigations have shown that majority of myoepithelial cells in benign tumours and carcinomas in situ exhibited strong positive labelling for both markers. In other malignant tumours strong immunoreactivity was observed in resting myoepithelial cells (MECs) and hypertrophic myoepithelial cells (HMECs), while the immunoreactivity in spindle-stellate myoepithelial cells (SMECs) and rounded myoepithelial cells (RMECs) was moderate. The granular-diffuse nuclear expression of p63 protein was observed only in myoepithelial cells. In terms of calponin, diffuse cytoplasmic expression was noted not only in myoepithelial cell but also in some stromal fibroblasts and vascular smooth muscle cells. The epithelial cells did not exhibit specific expression of the investigated markers. The obtained results indicate that p63 is a sensitive and more specific marker of myoepithelial cells in canine mammary tumours compared with calponin. These findings suggest that the immunohistochemical analysis peformed with the use of p63 can be a valuable complement of routine histological examinations of canine mammary tumours facilitating identification of tumours with myoepithelial component.

Heteroplasmic Mutations and Polymorphisms in the Cyb Gene of Mitochondrial DNA in Canine Mast Cell Tumours.

AIM: Identification of mutations and polymorphisms in the cytochrome b gene (Cyb) of mitochondrial DNA (mtDNA) in canine mast cell tumours and determinatiion of their association with the process of neoplastic transformation. MATERIALS AND METHODS: The samples comprised tumour tissues and blood obtained from 34 dogs of various breeds. Mutations and polymorphisms in the Cyb gene were detected using amplification and sequencing methods. RESULTS: Heteroplasmic mutations were detected at seven positions of mtDNA in 86% of the individuals. Blood and tumour heteroplasmy were recorded at five nucleotide positions of the Cyb gene, whereas tumour heteroplasmy was detected at two positions. Polymorphisms were detected at 14 Cyb gene positions in in the blood of 91% of dogs with mast cell tumours. CONCLUSION: The presence of numerous mutations and polymorphisms of Cyb in the blood and tumour tissues and the high frequency of heteroplasmy indicate their involvement in the process of neoplastic transformation in dogs.

Epidemiological assessment of the risk of canine mast cell tumours based on the Kiupel two-grade malignancy classification.

BACKGROUND: The degree of differentiation of mast cell tumours (MCTs) is the most important feature and reflects the morphological characteristics and metastatic potential of the tumour and its likely response to treatment and the prognosis. The aim of this study was to epidemiologically analyse the risk of MCT development in dogs according to breed, age, sex, size and anatomical location of the tumour using the Kiupel grading system. The analysis involved 492 dogs selected based on a histopathological assessment of 2763 canine skin tumours. A logistic regression analysis was performed to determine the odds ratios (ORs) with 95% confidence intervals. RESULTS: Mast cell tumours accounted for 17.8% of all diagnosed canine skin tumours. The highest risk of high-grade MCTs was noted in the Shar-Pei (OR 28.18, P < 0.001) and Weimaraner (OR 6.45, P = 0.023). The highest risk of low-grade MCTs was determined in the Boxer (OR 6.72, P < 0.001), and Pug (OR 6.13, P = 0.027). The scrotum (OR 31.72, P < 0.001), inguinal area (OR 17.69, P < 0.001) and axilla (OR 6.30, P < 0.001) had the highest risk of high-grade MCTs. The risk of high-grade MCTs increased with age and peaked in the oldest dogs, aged 11-16 years (OR 9.55, P < 0.001). A higher risk of low-grade tumours was noted in younger dogs (aged 4-6 years) (OR 8.54, P < 0.001) and females (OR 1.43, P = 0.001). Statistical analysis further revealed a higher risk of both low (OR 3.47, P < 0.001) and high-grade MCTs (OR 1.71, P = 0.006) in medium-sized dogs. CONCLUSIONS: This study demonstrated relationships between Kiupel grading system and phenotypic traits, age and location of canine MCTs confirming the complex biological nature of this tumour.

Identification of additional mitochondrial DNA mutations in canine mast cell tumours.

BACKGROUND: Research has revealed the presence of somatic mutations in mitochondrial DNA (mtDNA) of certain types of tumours. As this has not been studied for canine mast cell tumours, the aim of this study was to identify mutations in the hypervariable region of mtDNA in mast cell tumours in dogs and determine their association with the process of neoplastic transformation. RESULTS: Samples from 17 dogs with histopathologically confirmed mast cell tumours were analysed. The samples consisted of tumour tissues (n = 17), normal tissues (n = 17), and blood (n = 17). Amplicons of the displacement loop (D-loop) were sequenced and the obtained nucleotide sequences were subjected to bioinformatics analyses. Somatic mutations were detected in seven positions of the D-loop nucleotide sequences in 47 % of the dogs, while polymorphisms were identified in 94 % of the dogs. Most of these changes were homoplasmic, while heteroplasmy was detected in two individuals. Six new haplotypes were established as being characteristic for canine mast cell tumours. There was no association between the presence of the mutations and sex, haplotype, or malignancy grade assessed in 3 and 2-grade scales. CONCLUSIONS: Differences in the frequency of somatic mutations imply their direct association with the neoplastic transformation. However, their functional consequences and clinical significance are not clear. The mutations may be used for diagnosis and prognosis of canine mast cell tumours in the future.

Epidemiological and pathological features of primary cardiac tumours in dogs from Poland in 1970-2014.

Primary heart tumours affect less than 1% of dogs. Due to their rare incidence, every research showing the frequency of cardiac tumours is valuable. Routine diagnostics is often complemented with immunohistochemical analysis. This study was conducted on 110 patient records from all veterinary faculties in Poland from dogs diagnosed with heart tumours between 1970 and 2014. The dogs' age, breed and sex with tumour localisation and histopathological diagnosis were analysed. Because of its most common incidence, samples of haemangiosarcoma underwent further examination with assessment of the expression of cell markers that have not been evaluated earlier (i.e. minichromosome maintenance proteins and beta-catenin). We noted 111 tumours including 88.3% malignant and 10.8% benign ones. Haemangiosarcoma and aortic body tumour were the most frequent cardiac neoplasms in the dogs examined (45.9% and 27.9% of all tumours, respectively). Immunohistochemical analysis of haemangiosarcoma showed a positive expression of all markers examined. CD31, vimentin, and beta-catenin showed a positive reaction in all 11 samples examined. At least one proliferative marker (Ki-67, MCM-3 or MCM-7) showed a positive reaction in each sample. MCM-3 showed a higher expression than the two other proliferative markers (P = 0.006), but only Ki-67 showed a positive correlation with the mitotic index (P > 0.05, r = 0.89). Although beta-catenin, MCM-3 and MCM-7 showed a positive reaction in the haemangiosarcomas examined, their usefulness as diagnostic and prognostic factors should be a topic of further research.

Reclassification of Eimeria pogonae Walden (2009) as Choleoeimeria pogonae comb. nov. (Apicomplexa: Eimeriidae).

The presented paper provides a reclassification of Eimeria pogonae from Pogona vitticeps into the correct genus Choleoeimeria. A description of exogenous and endogenous stages of biliary coccidium is given. Sporulation of the oocysts was endogenous. The mature oocysts contained four sporocysts each with two sporozoites. Oocysts were ellipsoidal in shape, with average length/width ratio 1.7 and measured 28.4 (SD1.5) × 16.8 (SD 1.5). The micropyle, residuum, and polar granules were absent from the sporulated oocysts. Ovoidal in shape, sporosysts without Steida bodies contained residuum and two elongated and boat-shaped sporozoites. The endogenous stages of the coccidia were located mainly in the epithelium of bile ducts; however, single-epithelium cells of the gallbladder were also infected.