BackgroundEndocardiosis is the most common heart disease in Dachshunds and is therefore an important cause of cardiac morbidity and death. In recent years we have observed an increasing interest in the development of new genetic and genomic markers of heart disease. The discovery of miRNAs circulating in biofluids such as plasma or serum aroused researchers’ interest in using them as potential biomarkers. In the present study we analysed the expression of 9 miRNAs described in literature as being involved in cardiovascular pathology in the plasma of dogs suffering from endocardiosis.ResultsExpression analysis using the Real-time PCR method revealed that two out of nine miRNAs were significantly downregulated: the expression of miR-30b differed between ACVIM stage B and stage A (control) dogs; the expression of mi-133b differed ACVIM stage C and stage A dogs. 5 miRNAs (miR-125, miR-126, miR-21, miR-29b and miR-30b) showed a trend of downregulation in the ACVIM C group. Levels of miR-423 were the same in healthy and diseased dogs. Expression of miR-208a and 208b was not detected.ConclusionsmiR-30b could be a potential biomarker of ACVIM stage B heart failure in Dachshunds with endocardiosis and miR-133b could be a potential biomarker of ACVIM stage C. The lack of expression or lack of significant changes in expression in 7 miRNAs which are potential biomarkers of heart diseases in humans proves that findings from human medicine are not always directly reflected in veterinary medicine.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-014-0205-8) contains supplementary material, which is available to authorized users.

Cancer immunosuppression that facilitates tumor progression and metastasis evolves by development of an immunosuppressive network. The aim of this study was to assess this network in dogs with benign or malignant tumors with or without confirmed metastasis. The authors showed that the number of various T cell subpopulations was constant during tumor development; however the number of regulatory T cells (Tregs) was significantly higher in tumor-bearing dogs than in healthy individuals. The number of myeloid-derived suppressor cells (MDSCs) and their p-STAT3 expression (which is a negative regulator of hematopoiesis and regulates VEGF expression) were higher in cancer patients than in control dogs, however their number increased significantly in late-stage cancer patients. Canine mammary carcinomas with confirmed metastases to either lymph nodes or internal organs had greater MDSCs and Treg infiltration than benign mammary tumors or malignant mammary tumors for which metastases had not been detected. Similarly, expression of p-STAT3 and VEGF-C was the highest in tumors with confirmed metastases. This research shows changes occurring in the blood (n = 30 patients) and tumor tissue of patients (n = 100) during canine mammary tumor development. The findings should be considered preliminary because of the small number of samples. Nonetheless, the findings suggest that a high level of Tregs and MDSCs as well as high expression of p-STAT3 and VEGF-C may significantly contribute to mammary tumor progression and metastasis in dogs.

SummaryThe aim of the study was to assess the frequency of congenital heart defects in a population of dogs in Poland and to determine which breeds were affected by particular defects. A retrospective study of the medical records of cardiologically examined dogs revealed 301 cases of echocardiographically confirmed congenital heart defects. Dogs with congenital heart defects made up 2.7% of the dogs that underwent a cardiologic examination. The age at diagnosis ranged from 2 weeks to 190 months. Mixed breeds (33 dogs, 11%), Bull Terriers (31, 10%), Boxers (28, 9%), German Shepherds (17, 6%), Yorkshire Terriers (17, 6%), and French Bulldogs (16, 5%) were the most frequently affected breeds. Subaortic stenosis (120 cases, 33.9%), pulmonic stenosis (64, 18.1%), patent ductus arteriosus (59, 16.7%), mitral valve dysplasia (56, 15.8%), ventricular septal defect (24, 6.8%) and tricuspid valve dysplasia (17, 4.8%) were the most frequent congenital heart defects recognized in this study. Isolated congenital heart disease occurred in 258 dogs (86%), while multiple heart defects were noted in 43 dogs (14%). Most (60%) congenital heart defects were recognized in dogs older than 1 year. Early recognition of congenital heart defects is important for better patient care. Collecting information on the frequency of congenital heart defects in particular breeds will be useful in educating breeders and thus in improving the overall health of the breed.

BackgroundChronic mitral valve disease is frequently seen in the Dachshund. Dachshunds (n=207) made up 11.73% of the dogs admitted to the Cardiology Service at the Small Animal Clinic, Warsaw University of Life Sciences, Poland (first visits only).ResultsOf these, 35 dogs had no clinically detectable heart disease while 172 had chronic valve disease with the mitral valve affected most often (130 dogs), both mitral and tricuspid valves infrequently (39 dogs) and rarely the tricuspid valve (3 dogs). Males were affected more frequently than females and the average age of dogs with chronic valve disease was 11.9 years for females and 11.3 years for males. A majority of the diseased Dachshunds were classified as ISACHC 2 (79), followed by ISACHC 1 (60). Most frequent clinical signs noted by owners included coughing, exercise intolerance, dyspnea and tachypnea. Heart murmurs were generally louder with increased disease severity; however there were 20 dogs in the ISACHC 1 group with no audible heart murmurs. The most frequent electrocardiographic abnormalities included an increased P wave and QRS complex duration, increased R wave amplitude and tachycardia. With increased disease severity, echocardiography revealed an increase in heart size. A higher ISACHC class was related to increased heart size (based on echocardiography) and increased percentage of patients exhibiting enlargement of both left atrium and left ventricle (based on radiography).ConclusionsThe Dachshund is often affected by chronic mitral valvular disease with a late onset of associated clinical signs and few cardiac complications.

BackgroundIn recent years advances have been made in the investigative methods of molecular background of canine heart disease. Studies have been conducted to identify specific genes which, when pathologically expressed, could lead to the dysfunction of the canine heart or are correlated with heart failure. For this purpose genome wide microarray experiments on tissues from failing hearts have been performed. In the presented study a whole genome microarray analysis was used for the first time to describe the transcription profile of peripheral blood nuclear cells in dogs with heart failure. Dogs with recognized heart disease were classified according the ISACHC (International Small Animal Cardiac Health Council) classification scheme as class 1 (asymptomatic) - 13 dogs, class 2 (mild to moderate heart failure) - 13 dogs and class 3 (severe heart failure) - 12 dogs. The control group consisted of 14 healthy dogs. The clinical picture of the animals included: animal history, clinical examination, echocardiographic examination and where applicable electrocardiographic and radiographic examinations.ResultsIn the present study we identified four sets of differentially expressed genes, namely heart-failure-specific genes and ISACHC1-specific genes, ISACHC2-sepcific genes and ISACHC-3 specific genes. The most important set consisted of genes differentially expressed in all dogs with heart failure, despite the ISACHC stage. We identified 71 heart-failure-specific genes which were involved in two statistically significant receptor signalling pathways, namely angiotensinR - > CREB/ELK-SRF/TP53 signalling and ephrinR - > actin signalling. The number of ISACHC1-specific genes was 83; ISACHC2-specific genes - 1247 and ISACHC3-specific - 200.ConclusionsThe transcriptomic profile of peripheral blood nuclear cells in dogs with heart failure seems to reflect the presence of clinical signs of the disease in patients based on the observation that the largest number of differentially expressed genes was identified in ISACHC 2 group of patients. This group consists of dogs just starting to show clinical signs of heart failure. A set of genes was also found to have changed expression in all dogs with heart failure, despite the stage of the disease.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-509) contains supplementary material, which is available to authorized users.