A probable case of "lumpy jaw" in early medieval (11th - 12th c.) cattle from a stronghold in Kruszwica, Poland.

OBJECTIVE: The purpose of this article is to try to determine the probable cause of the disease from which the study animal suffered. MATERIALS: The skeletal material included a caudal fragment of a cattle mandible. The specimen, exhibiting chronic disease was separated from approximately 10,000 early medieval cattle remains discovered during excavations of the former Kruszwica stronghold. METHODS: The bone was underwent macroscopic, radiological and histopathological examination. RESULTS: Location, macroscopic, microscopic and X-ray images of the lesions within the examined mandible indicate it could have been caused by the actinomycosis. CONCLUSIONS: In the face of infection, no effective therapies were undertaken in the Middle Ages. SIGNIFICANCE: Descriptions of lumpy jaw in the paleopathological literature are rare. This disease, due to its background and course, eliminated animals from breeding for centuries until the era of antibiotics. The case described in our paper is in an advanced stage, but its adult age suggests that efforts were possibly made to keep the cow alive as long as possible, indicating the significant economic importance of the animal. LIMITATIONS: This analysis is limited by the absence of other anatomical elements of the affected animal, which impacts the interpretation of the palaeopathological bone. SUGGESTIONS FOR FURTHER RESEARCH: It is recommended that similar studies are conducted on better preserved and more numerous cattle assemblages.

Canine urothelial carcinoma: expression of Periostin in spontaneous canine urothelial carcinoma and its correlation with histological features.

The tumor microenvironment is considered one of the main players in cancer development and progression and may influence the behavior of cancer cells. Periostin (POSTN) is an extracellular matrix protein, and its main functions are induction of fibrillogenesis, fibroblastic cell proliferation and migration, enhancing regeneration in normal tissue, and promoting metastasis in case of neoplasia. POSTN has already been studied in humans in several normal tissues, inflammatory processes, and neoplasms, revealing an important role in tumor progression in various types of cancer, such as colon, lung, head and neck, breast, ovarian, and prostate. In these latter, high levels of POSTN are usually associated with a more aggressive tumor behavior, tumor advanced stages, and poor prognosis, while in human bladder urothelial carcinoma (BUC), unlike in most tumors, POSTN expression seems to be downregulated. The expression of this marker has been poorly investigated in veterinary medicine; thus, this study aimed to immunohistochemically investigate the presence and the intensity of POSTN expression in canine BUCs and to determine a possible relationship between POSTN expression and histopathological features such as mitotic count and muscular and vascular invasions. For the present retrospective study, archived samples from 45 canine BUCs and 6 non-neoplastic canine bladders were considered for histological evaluation and immunohistochemical examination for the expression of POSTN. POSTN expression was semi-quantitatively assessed considering both the percentage of the neoplastic stroma positive for POSTN and the intensity of the immunohistochemical labeling. Histologically, 38 out of 45 tumors were papillary and 7 out of 45 were non-papillary. All tumors were infiltrating, being that 21 were muscle-invasive, and a significant correlation between this feature and vascular invasion emerged (P = 0.0001). In normal bladder tissue, as reported in humans, a thick and strongly positive belt of POSTN was visible, and in canine BUCs, stating that the expression is comparable with human benign as well as malignant bladder tissue, a general decrease in POSTN expression was observed except for a strongly labeled ring of POSTN observed around some neoplastic nodules infiltrating the muscle layer. Moreover, POSTN expression and mitotic count were significatively inversely correlated (P = 0.0015). The fact that POSTN protein is less expressed in urothelial carcinomas than in the normal bladder supports what was reported in human BUCs and, together with the negative correlation between mitotic count and protein expression that emerged in the present retrospective study, encourages further prospective follow-up studies to verify the possible role of POSTN in canine BUCs as a prognostic marker, and also as a possible target for the development of future anticancer therapies.

Study on the expression of testin in the testes of dogs.

Introduction: Testin is a protein involved in cell mobility, adhesion and colony formation. In rats, testin presence has been reported in the testes, and its possible role in spermatogenesis has been suggested. Studies in humans also suggest a possible role of testin as a cancer suppressor protein. In the dog, which represents both an important pet species and a good animal model for studying biological and pathological testicular processes, the presence of testin has never been reported. Material and Methods: In the present study, the expression of testin in foetal, prepubertal, adult and aged canine testes was investigated. Testes from 5 adult and 3 aged dogs, from 2 one-month-old puppies and from 2 foetuses miscarried at the end of pregnancy were immunohistochemically examined with a commercial antibody against testin. Results: Testin was intensely expressed in Sertoli cells in every testis examined. Spermatids were also positive for testin in mature dogs and in the testicular areas of the aged ones which were not atrophic. Weak expression of testin was also detected in all testes examined. Conclusion: The present study, the first demonstrating the presence of testin in canine testes, provides the basis for further dog-human comparative research and for studies on the role of this protein in canine physiology, reproduction and testicular pathologies.

First report of primary testicular leiomyosarcoma in two dogs.

BACKGROUND: Testicular tumours are common in dogs and, among them, interstitial cell tumours, seminomas and sustentacular cell tumours are the most reported. Mesenchymal testicular tumours are rarely reported in humans as in veterinary medicine where only three cases of sarcomas (leiomyomas and leomyosarcomas) have been described in two stallions and in a ram. CASE PRESENTATION: The present cases regarded a 12-year-old mixed-breed dog and a 10-year-old American Staffordshire Terrier that underwent bilateral orchiectomy. Formalin fixed testes were referred for histopathological diagnosis. At gross examination, in one of the testes of both dogs, a white, firm and variably cystic testicular mass, effacing and replacing the testicular parenchyma was detected. Samples were collected from both neoplastic and contralateral testes, routinely processed for histology and serial sections were also examined immunohistochemically with primary antibodies against cytokeratins, vimentin, Von Willebrand factor, inhibin-α, α-smooth muscle actin, smooth muscle myosin and desmin. Histopathological features as well as the immunohistochemical results, positive for vimentin, actin, myosin and desmin, confirmed the mesenchymal origin and the myoid phenotype of both testicular tumours supporting the diagnoses of leiomyosarcoma. CONCLUSIONS: To the authors knowledge these are the first cases of primary testicular sarcoma reported in the canine species. However, even rare, these tumours deserve to be considered in routine diagnosis when a testicular spindle cell tumour is observed. The immunohistochemical panel applied was useful to distinguish the present tumours from undifferentiated Sertoli cell tumours confirming the diagnosis of leiomyosarcoma.

Prevalence of Tumours and Tumour-like Lesions in Domestic and Exotic Animals from Lower Silesia and its Surrounds in Poland in 2014-2017.

Introduction: An analysis of samples originating from domestic and exotic animals from Lower Silesia but also from other parts of Poland was carried out based on research conducted in 2014-2017. Material and Methods: The materials used for the study were 11,338 tumour samples taken in vivo during surgery and as biopsies and posthumously during necropsies. They were sent to the Department of Pathology at Wroclaw University of Environmental and Life Sciences for histopathological diagnosis. Results: The largest group were canine tumours, of which there were 9,745 (85.95%), followed by feline tumours, totalling 1,397 (12.32%), tumours from exotic animals (186; 1.64%), from horses (7; 0.06%), and from cows (2; 0.02%). A significant number of cases of animals suffering from more than one tumour were also found, which had not been frequently diagnosed previously. Conclusion: The number of neoplasms diagnosed in pets and exotic animals is increasing every year. The average animal age at diagnosis continues to fall. The greatest number of neoplasms were diagnosed in mixed-breed dogs and cats, and the number of tumours in a pure breed strictly correlated with breed's popularity in the research period. Mesenchymal tumours are still the most prevalent type of tumours in dogs, while in cats epithelial tumours predominate. The neoplasm case pattern in animals conforms to that in humans in the same area.

Tracheal Hemangioma Causing Lung Emphysema and Pneumopericardium in a Rabbit-A Case Report.

A pet rabbit (female, 8 years old, and mixed breed) with symptoms of dyspnea, apathy, and weight loss was treated for an acute respiratory infection. Due to the lack of improvement, it was referred to the Imaging Diagnostics Laboratory of the Department and Clinic of Surgery for a computer tomography scan of the thoracic cavity. The examination revealed the presence of air in the pericardial sac, a pneumopericardium, along with pulmonary emphysema. A few minutes after the examination, the rabbit developed circulatory and respiratory failure and died. Necropsy confirmed the presence of a pneumopericardium and pulmonary emphysema, and revealed, in the tracheal lumen, the presence of a tumor histologically consistent with hemangioma. A spontaneous pneumopericardium occurs when air from the respiratory system moves into the pericardial sac. This is the first case of the simultaneous occurrence of tracheal hemangioma and a pneumopericardium in a rabbit.

Simultaneous poisoning of 48 birds of prey - bendiocarb determination with the use of UHPLC-ESI-MS/MS method in fatal case from Eastern Europe.

Aim: Bendiocarb is used against a wide range of insects but has already been withdrawn from the market in some countries. It poses a high risk to birds as they can accidentally ingest it while searching for food, followed by toxic effects. This paper presents the results of toxicological and histopathological studies of 48 cases of intentional birds of prey poisoning with bendiocarb in Eastern Europe, specifically Poland. Material and methods: A novel ultra-high-performance liquid chromatography-triple quadrupole-tandem mass spectrometry (UHPLC-ESI-MS/MS) method for bendiocarb determination in animal liver samples was developed and fully validated. The sample preparation technique was based on one-step precipitation of proteins with cold acetonitrile. The internal standard used was carbaryl-d7. Full time of analysis was less than 10 minutes. The application of the UHPLC-ESI-MS/MS method allowed us to achieve the lowest LOQ (1 ng/g) of bendiocarb in biological samples to date. Results: Necropsies and histopathological examinations of common ravens (Corvus corax), western marsh harriers (Circus aeruginosus), red kites (Milvus milvus), and a white-tailed eagle (Haliaeetus albicilla) revealed multi-organ toxicity manifested as congestion, oedema, or stagnation of blood. An analytical investigation confirmed the presence of bendiocarb in liver in the 1808-7721 ng/g range. Furthermore, the presence of this compound was qualitatively confirmed in the stomach and beak contents and also in the bait located near the deceased animals. Conclusions: A comprehensive forensic examination is crucial to monitor wildlife fatalities, especially applying a combined analytical and histopathological approach to identify and eliminate highly toxic substances which pose a threat to the ecosystem.

Case report laparoscopy-assisted pre-pubic urethrostomy as a palliative procedure for resection of distal urethral tumor in a female dog.

BACKGROUND: This paper presents the first described case of laparoscopy-assisted prepubic urethrostomy and laparoscopic resection of a tumor of the distal part of the urethra in a female dog as a palliative treatment. CASE PRESENTATION: An intact, 11 -year-old, mixed breed female dog, weighing 15 kg, was admitted with signs of urinary obstruction and difficulty with catheterization. Vaginal, rectal, and endoscopic examinations revealed a firm mass in the pelvic cavity at the level of the pelvic urethra. Ultrasound and computed tomography examination showed enlargement of the urethral wall (5.5 cm width and 3 cm thick), which was significantly restricting the patency of the urethra. The lesion affected only the distal part of the urethra without the presence of local or distant metastatic changes. The affected portion of the urethra was laparoscopically removed while performing pre-pubic urethrostomy with laparoscopy. The patient regained full consciousness immediately after the end of anesthesia, without signs of urinary incontinence. Histopathological examination of the removed urethra revealed an oncological margin only from the side of the bladder. In the period of 2.5 months after the procedure, the owner did not notice any symptoms that could indicate a postoperative recurrence, which was diagnosed three months after the procedure. CONCLUSIONS: Pre-pubic urethrostomy can be successfully performed with the assistance of laparoscopy. The use of minimally invasive surgery will allow, in selected cases, removal of the urethral tumor, and in inoperable cases, to perform a minimally invasive palliative pre-pubic urethrostomy.

Does open ovarian biopsy in prepubertal age affect ovarian reserve in a rat model?

BACKGROUND: Partial resection of the ovary carries a possible risk of fertility reduction. We studied the influence of open ovarian biopsy on ovarian reserve, including anti-Müllerian hormone and follicle-stimulating hormone serum level evaluation, in a prepubertal rat model. METHODS: Interventions - the initial surgery was unilateral ovarian biopsy (38 rats, group B1, B2) or unilateral ovarian biopsy and ovarian resection of the contralateral gonad (38 rats, group BR1, BR2). The second operation was bilateral ovarian resection and total resection of the remaining ovary. All rats had hormone serum levels evaluated. The control group had only a blood test taken and bilateral ovarian resection done at the second intervention (30 rats, group C1, C2). The collected tissue was examined estimating follicle count and anti-Müllerian hormone immunoexpression. RESULTS: Anti-Müllerian hormone levels were significantly lower at the second intervention in the group BR2 but significantly higher in the group C2. Follicle-stimulating hormone levels were significantly higher in all but one group (BR2). CONCLUSIONS: Biopsy itself might not reduce ovarian reserve if done properly but we should know its possible negative effects in the case of a single remaining ovary.

Urothelial cancer of the prostate gland. Immunohistochemical analysis of two cases of rare canine cancer.

INTRODUCTION: The study aimed to diagnose urothelial cancer of prostate gland (UCPG) in dogs as the primary focus and in its metastasis based on the expression of specific proteins used in immunohistochemical diagnosis of prostate cancer in men. MATERIAL AND METHODS: The study was carried out on specimens collected during a post-mortem examination from macroscopic lesions of the prostate glands from two dogs. The immunoexpression of the following proteins was verified: prostate-specific antigen (PSA), high molecular weight cytokeratins (HMWCK), cytokeratin 7 and 20 (CK-7,-20), E-cadherin, von Willebrand factor, cyclooxygenase-2 (COX-2), microsomal PGE2-1 synthase (mPGES-1) and component of the minichromosome 7 maintenance complex (MCM7). RESULTS: All markers, except for PSA, were expressed both at the primary tumour site and in the metastasis. CONCLUSIONS: The immunohistochemical approach was more useful for the diagnosis of UCPG in dog than typical histopathological staining methods because it allowed for precise determination of features, type and grade of the tumour that may affect its early detection and treatment.

Expression of Periostin in Mammary Cancer Cells of Female Dogs.

BACKGROUND/AIM: Periostin (POSTN) has a significant role in proliferation and migration of tumour cells as well as tumour progression. This study aimed to determinate POSTN expression in cancer cells in malignant and benign tumours of the mammary gland in female dogs. MATERIALS AND METHODS: All together 83 cancers, 24 adenomas and 7 unchanged fragments of the mammary glands of bitches were investigated. Immunohistochemistry was performed using anti-POSTN, Ki-67 and HER2 antibodies. RESULTS: POSTN expression was observed in cancer cells in 31.3% of malignancies and 12.5% of benign tumours. A significantly positive correlation between expression of POSTN in cancer cells and the degree of histological malignancy, expression of Ki-67 antigen and expression of POSTN in CAFs was found. CONCLUSION: The obtained results suggest the possible participation of POSTN in the process of carcinogenesis and progression of mammary tumors in bitches.

A modified Sydney system for the diagnosis of chronic gastritis in dogs.

BACKGROUND: The Sydney system for assessing inflammatory lesions in the gastric mucosa is based on endoscopic and histological examinations. This study aimed to apply the Sydney system to diagnose gastritis in dogs. The study also compared the results of endoscopic and histological examinations conducted on gastric mucosal biopsy specimens. A total of 56 dogs with chronic vomiting were analyzed in the study. The physical appearance of the gastric mucosa was assessed through endoscopic examination, while the severity of the gastric inflammation, inflammation activity, glandular atrophy, and intestinal metaplasia were assessed by histopathological examination. RESULTS: The endoscopic examination confirmed the presence of inflammatory lesions affecting the gastric corpus and pylorus in all the dogs, although the severity of these lesions differed between the individuals. Reflux gastritis was the most commonly observed gastric inflammation. In the histopathological examination of the gastric mucosal samples, inflammatory lesions were found in the gastric corpus of 53 dogs, while 55 dogs had lesions in the pylorus. This corresponds to a 96.4% agreement between the methods. CONCLUSIONS: The Sydney system is a useful tool for macroscopic and microscopic assessment of changes in the gastric mucosa as it enables the determination of inflammation type and severity, which helps the canine gastroenterologists to reliably compare the results of the tests performed in different facilities. Besides, the use of the Sydney system in diagnosing lesions facilitates the selection and effective monitoring of treatment. However, despite a high rate of agreement between the results of endoscopic and histopathological examinations, it is recommended to use both these methods for the assessment of the gastric mucosa in dogs.

Expression of Periostin in Cancer-associated Fibroblasts in Mammary Cancer in Female Dogs.

BACKGROUND/AIM: Mammary neoplasms, like breast neoplasms in women, are one of the most common tumours in female dogs. Cancer-associated fibroblasts (CAFs) found in the tumour stroma play a role in angiogenesis and increase cell migration, contributing to tumour growth and progression, as well as metastasis. The aim of our work was to determine the level of periostin (POSTN) expression in CAFs in mammary tumours of female dogs. MATERIALS AND METHODS: The research material consisted of 77 carcinomas and 24 adenomas of the mammary ridge in female dogs. Immunohistochemistry tests were performed using antibodies directed against the antigens POSTN, Ki-67, ERB-B2 receptor tyrosine kinase 2 (HER2), vimentin, and alpha smooth muscle actin (αSMA). Expression of POSTN at the mRNA level was determined using real-time polymerase chain reaction methods in 20 cases of mammary neoplasms. RESULTS: Expression of POSTN in CAFs was observed in 92% of mammary cancer samples and in 25% of mammary adenoma samples in female dogs. A statistically significant increase in POSNT expression in CAFs was found in the carcinomas compared with mammary adenomas in female dogs. Expression of POSTN in CAFs in mammary carcinomas in female dogs positively correlated with the histological malignancy grade of tumours and the expression of Ki-67 proliferative antigen. CONCLUSION: Our results suggest a role of POSTN on the pathogenesis of mammary tumours in female dogs. Moreover, POSTN may prove to be a useful marker in the evaluation of cancerous stroma of mammary tumours in female dogs, and may have prognostic significance.

Expression of Podoplanin in Mammary Cancers in Female Dogs.

BACKGROUND/AIM: Mammary neoplasms are very common tumours in female dogs. Cancer-associated fibroblasts (CAFs) play an important role in the oncogenesis process. One of the useful proteins used in the diagnostics of CAFs cells is podoplanin (PDPN). The aim of our study was to assess the expression of PDPN in mammary cancer in female dogs. MATERIALS AND METHODS: Our study cohort included 61 cancers and 21 adenomas of the mammary tumour in bitches. Expression of podoplanin, Ki-67 and HER2 was determined using the Immunohistochemical (IHC) method. PDPN expression at the mRNA level was determined using real-time PCR. RESULTS: Expression of PDPN in CAFs was observed in 22.9% of cases of mammary cancers in bitches, with no PDPN expression in adenomas. A positive correlation was found between the expression of PDPN in CAFs and the grade of histological malignancy and expression of Ki-67. CONCLUSION: PDPN plays a significant role during the process of carcinogenesis of mammary tumours in female dogs.

Fatal pulmonary hemorrhage in a horse during bronchoalveolar lavage - single case report.

BACKGROUND: Pulmonary hemorrhage is a rare cause of death in horses. Hemorrhage within the respiratory tract has many causes, including mycosis of the guttural pouch, invasive procedures causing serious trauma to nasal conchae, or lung biopsy. We report on a rare case of a fatal pulmonary hemorrhage in a horse after a severe cough during bronchoalveolar lavage. To the best of our knowledge, this is the first report of spontaneous hemorrhage in a horse during bronchoalveolar lavage. CASE PRESENTATION: A 21-year-old mare which belonged to the didactic herd of The Faculty of Veterinary Medicine underwent BAL procedure for training purposes. Clinical examination prior to the procedure did not reveal any abnormalities and the horse had been classified as healthy. The horse was sedated with 0.01 mg/kg of detomidine and 0.01 mg/kg of butorphanol. The silicon BAL catheter was passed through the nasal passage into the trachea and then into the bronchus. Before catheter was wedged, the mare began to cough heavily and massive haemorrhage from mouth and nostrils occurred. Despite fluid therapy, shock occurred within 15 min and the mare was euthanized. Upon necropsy, site of hemorrhage was identified in the left lobar caudal bronchi, from a large blood vessel running directly beneath the bronchial wall. Upon histology, a chronic lympho-plasmocytic inflammatory process in left bronchi was identified. Moreover, Masson's trichrome staining revealed severe, perivascular fibrosis. CONCLUSION: Although BAL is a relatively safe procedure, and such complications should be treated as extremely rare, this case indicates that, in some individuals with specific subclinical problems, even mild physical force such as a cough can lead to rupture of the artery.

Identification of probable telangiectatic osteosarcoma from a dog skull from multicultural settlement Polwica-Skrzypnik in Lower Silesia, Poland.

This report presents canid cranial skeletal pathology from an excavation associated with the Przeworsk culture (III c. BC - V c. AD). The dog skull, an intentional inhumation, was dated to the Roman influence and the Migration period (I - V c. AD. The dog was a relatively large animal with a shoulder height calculated as approximately 60 cm. Massive bone changes localized on the facial surface of the left maxilla required a multistage diagnostic protocol. In addition to traditional macroscopic and morphometric evaluation, we used modern diagnostic imaging techniques such as digital radiography, computed tomography and 3D reconstruction. These, along with histopathological studies, allowed us to identify a primary malignant bone tumor: telangiectatic osteosarcoma.

Cardiomyocyte marker expression in dogs with left atrial enlargement due to dilated cardiomyopathy or myxomatous mitral valve disease.

INTRODUCTION: Dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD) are common heart conditions in dogs. They have different etiology and pathogenesis and although other studies focused on changes in the left ventricles of the affected hearts, the aim of our study was to assess the expressions of some intrinsic proteins in the enlarged left atria. MATERIAL AND METHODS: We performed an immunohistochemical analysis of left atrial specimens obtained from 15 dogs with DCM, 35 dogs with MMVD and six control dogs. We assessed the expression of following proteins: SERCA1, SERCA2, sarcomeric actinin, smooth muscle actin, and dystrophin. RESULTS: We noted a higher percentage of SERCA1-positive cells in the MMVD group and lower percentage of dystrophin-positive cells in the DCM group as compared to control group. The expression of other proteins was similar in the hearts of control dogs and dogs with heart diseases. CONCLUSIONS: The observed changes in the expression patterns of some proteins in the atria of dogs with DCM and MMVD suggest that atrial enlargement relies not only on volume overload, but also alterations of the intrinsic proteins can contribute to the pathogenesis of dilated cardiomyopathy.

The immunohistochemical evaluation of selected markers in the left atrium of dogs with end-stage dilated cardiomyopathy and myxomatous mitral valve disease - a preliminary study.

BACKGROUND: Dilated cardiomyopathy (DCM) and myxomatous mitral valve disease (MMVD) are the most common diseases noted in dogs. Although their pathogenesis varies, both include a significant enlargement of the left atrium. The study was carried out on left atrial specimens obtained from 56 dogs, including those from 34 dogs with clinically diagnosed MMVD, 15 dogs with DCM and 7 dogs without heart disease (control group). Dogs in the MMVD and the DCM groups presented with left atrial enlargement and stage D heart failure. The specimens underwent immunohistochemical examination using desmin, vimentin, periostin and caspase-3 antibodies. RESULTS: There were alterations in the expression of the studied proteins in the study groups compared to the control group. The changes included: irregularity of desmin cross-striation and desmosomes, a higher amount of vimentin-positive cells, a change in the periostin expression pattern from cytoplasmic to extracellular, and a lower expression of caspase-3. The alterations were more pronounced in the DCM group than in the MMVD group. CONCLUSIONS: During heart failure, the pattern of desmin, vimentin, periostin and caspase-3 expression alters in the left atrium, regardless of the cause. The changes are more pronounced in dogs with DCM than in dogs with MMVD and similar left atrial enlargement, suggesting that volume overload may not be the only cause of myocardial changes in DCM.

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.

A comparison of the histopathologic pattern of the left atrium in canine dilated cardiomyopathy and chronic mitral valve disease.

BACKGROUND: Dilated cardiomyopathy (DCM) and chronic mitral valve disease (CMVD) in dogs are associated with heart chamber enlargement, also of the left atrium. DCM is often accompanied by rhythm disturbances (mainly atrial fibrillation or ventricular arrhythmias). In CMVD, arrhythmias are observed less frequently. It is still unclear whether left atrial enlargement in these diseases results from volume overload or if it is also connected with other factors (e.g. rhythm disturbances). This study was conducted on the left atrial myocardial specimens from 31 dogs, including those from 16 dogs with clinically diagnosed DCM and 15 dogs with CMVD. After fixation and staining (using haematoxylin-eosin and Masson-Goldner trichrome stain), the specimens underwent evaluation. Parenchymal changes (fibrosis, fatty infiltration, and vessel narrowing), degenerative changes (loss of striation, changes in cardiomyocyte structure, and abnormal cell nuclei) and the presence of inflammatory infiltrates were assessed. RESULTS: More interstitial fibrosis (median 4 vs. 2.5 grid fields; p < 0.05) and less perivascular fibrosis (median score 1 vs. 2; p < 0.05) was observed in the DCM group compared to the CMVD group. Moreover, less distinct vessel narrowing was observed in the DCM group than in the CMVD group (median lumen area ratio 0.3 vs. 0.26 respectively; p < 0.05). Dogs with DCM showed more strongly defined degenerative changes than the CMVD dogs (median nuclei enlargement score 3 vs. 1, median loss of striation score 3 vs. 2 and median structural alterations score 3 vs. 2, respectively; p < 0.05). CONCLUSION: The obtained results indicate a different nature of changes occurring in the left atrial myocardium of dogs with DCM compared to dogs with mitral valve disease, including differences in vessel narrowing, cardiomyocyte degeneration and in the distribution of connective tissue.