IntroductionThe prevalence of arrhythmias in dogs and the influence of sex, breed, age, and body weight were analysed over a seven-year span.Material and MethodsIn total, 1189 referrals for cardiological examination by electrocardiography were received at one academic centre in Poland between 2008 and 2014. The largest proportion of the examined dogs were cross-breeds with body weight below 25 kg (n = 153, 12.87%), followed by German Shepherds (n = 122, 10.26%), Labrador Retrievers (n = 68, 5.72%), Yorkshire Terriers (n = 63, 5.3%), and Boxers (n = 60, 5.05%). Retrospective analysis was made of 1201 standing or right recumbent electrocardiograms without pharmacological sedation. The prevalence of arrhythmias was examined in terms of sex, age, body weight, and breed of the dogs.ResultsA total of 630 (52.46%) electrocardiograms showed no signs of arrhythmia, but 96 (7.99%) and 475 (39.55%) pointed to physiological and pathological arrhythmias respectively. The most commonly diagnosed type was atrial fibrillation with 33.68% incidence, followed by ventricular arrhythmias (28%), sinus pauses (27.58%), supraventricular arrhythmias (24%), and atrioventricular blocks (22.95%). Pathological arrhythmias were most commonly found in male dogs and in German Shepherds.ConclusionsAtrial fibrillation predominated, followed by premature ventricular complexes. Male dogs were generally more prone to heart rhythm disturbances.

Background: Hypertrophic cardiomyopathy is the most common cardiovascular cause of death in cats. Although the majority of cats remain asymptomatic, some may develop signs of chronic heart failure due to diastolic failure, arterial thromboembolism (ATE) or sudden cardiac death. Therefore, it is crucial to identify individuals that are in high risk of developing cardiac complications before the onset of life-threatening signs. Oxidative stress is the imbalance between the production and neutralisation of reactive oxygen species. Uncontrolled reactive oxygen species overproduction leads to protein and lipid peroxidation and damages the DNA strands, injuring the cells and leading to their death. The aim of the study was to evaluate the oxidative state in cats with hypertrophic cardiomyopathy and healthy controls. Results: In total, 30 cats divided into three groups were assessed: animals with clinically evident hypertrophic cardiomyopathy (HCM; n = 8), subclinical hypertrophic cardiomyopathy (SUB-HCM; n = 11) and healthy controls (n = 11). The activity of superoxide dismutase was statistically significantly lower in animals with symptomatic and asymptomatic hypertrophic cardiomyopathy (HCM 0.99 ± 0.35 U/mL; SUB-HCM 1.39 ± 0.4 U/mL) compared to healthy cats (2.07 ± 0.76 U/mL, p < 0.01). The activity of catalase was significantly lower in the SUB-HCM group (19.4 ± 4.2 nmol/min/mL) compared to the HCM (23.6 ± 5.9 nmol/min/mL) and the control (30 ± 7.5 nmol/min/mL, p < 0.01) group. The activity of glutathione peroxidase was 4196 ± 353 nmol/min/mL in the HCM group, 4331 ± 451 nmol/min/mL in the SUB-HCM group and 4037 ± 341 nmol/min/mL in the control group and did not differ significantly between groups. The total antioxidant capacity of plasma was 602 ± 65.5 copper reducing equivalents (CRE) in the HCM group, 605.9 ± 39.9 CRE in the SUB-HCM group and 629 ± 77.5 CRE in the healthy cats and did not differ significantly between the groups. Conclusions: Activities of superoxide dismutase and catalase differed in cats with hypertrophic cardiomyopathy, however the activity of the latter was only significantly lower in asymptomatic stage of the disease. The potentially beneficial effect of antioxidative substances on the disease progression in the asymptomatic and symptomatic stage of this disease should also be examined.

Introduction: Pacemaker implantation is the only effective symptomatic treatment for life-threatening bradyarrhythmias. Major complications observed after implantation of cardiac pacemakers include lead dislocation, loss of pulse generator function, and inadequate stimulation. The aim of this retrospective single-centre study was to analyse the indications for pacemaker implantation and the incidence and types of complications associated with this procedure in dogs treated for symptomatic bradyarrhythmia. Material and Methods: The retrospective analysis included 31 dogs with symptomatic bradyarrhythmia, implanted with permanent cardiac pacemakers in 1992–2017. The list of analysed variables included patient age, breed, sex, indication for pacemaker implantation, comorbidities, and the incidence of procedure-related complications along with the type thereof. Results: The most common indication for pacemaker implantation was 3rd degree AVB, followed by SSS, advanced 2nd degree AVB, and PAS. Pacemaker implantation was associated with a 35% overall complication rate and 6.45% periprocedural mortality. There were no significant differences in terms of procedure-related complications with regard to age, sex, breed, indications for pacemaker implantation, or comorbidities. Conclusions: Cardiac pacing is the only effective treatment of symptomatic bradycardia, but as an invasive procedure, may pose a risk of various complications, including death.

AbstractIntroductionAlthough peripheral blood analysis has become increasingly automated, microscopy is the only available method for the diagnosis of anisocytosis and poikilocytosis. The aims of the study were to compare RBC volume data obtained with two different analysers and by manual assessment of smears and to compare this data between dogs in various stages of heart failure secondary to degenerative mitral valvular (DMV) disease. The impact of diuretic administration on RBC morphology was also assessed.Material and MethodsSixty-eight dogs, 56 in different stages of DMV disease and 12 as healthy controls, were studied. Impedance and flow cytometry haematological analyses were performed for each animal. Additionally, two smears were prepared for manual analysis. RBC structure, staining, and size differences were recorded.ResultsThere were no significant differences between the blood morphological parameters assessed using haematological analysers nor between dogs receiving diuretic treatment and those not treated. Based on the manual smear, significantly higher erythrocyte anisocytosis was observed in the dogs with symptomatic DMV disease than in the control group.ConclusionHaematological analysers based on impedance and flow cytometry provide reliable and comparable morphological results in dogs with heart failure. However, microscopic assessment of blood smears is a more reliable tool to detect erythrocyte anisocytosis.

BackgroundPrecise understanding of the dimensions of the vascular lumina is essential for accurate interpretation of cardiac vessels imaging. To the authors’ best knowledge, this is the first study focusing on the ultrasound measurement of the right coronary artery (RCA) in the horse. The aim of this study was to determine both the ultrasonographic range of the normal diameter and lumen area of the RCA in horses and the influence of gender, age and level of training on the RCA dimensions. An additional aim of the study was to assess intra- and inter-observer repeatability of the collected measurements.MethodsThirty-six privately owned, healthy horses were included in the study. The internal lumen diameter and the area of the RCA were measured in the right parasternal long axis view in the 3rd intercostal space during systole and diastole. The results were compared between groups using the analysis of variance (ANOVA) and Student’s t-test. The correlation between the physiological parameters and the RCA was assessed using Pearson correlation coefficient. Student’s t-test was used to compare the results obtained by two researchers and from two scanners.ResultsThe mean diameter of the RCA was 13.1 ± 1.5 mm in systole and 11.5 ± 1.3 mm in diastole, and the mean area was 1.3 ± 0.2 cm2 and 1.1 ± 0.2 cm2, respectively. There were no statistically significant measurement differences between geldings and mares. A positive correlation between body weight and RCA dimensions as well as height and RCA dimensions were seen. There was a negative correlation between the age and the RCA area. A statistically significant difference in the RCA area was seen between race and retired horses. Intra- and inter-observer agreement was strong with a few statistically significant differences.ConclusionsThe age, size, and level of training may affect the ultrasound measurement of the RCA in horses. Non-invasive transthoracic echocardiography may be used to assess the size of the right coronary vessel in various types of horses.