Risk Factors for Atrial Fibrillation in the Dog: A Systematic Review.

Different risk factors for atrial fibrillation (AF) development have been identified in numerous studies on humans, but this information is less clearly available on the dog. The aim of this systematic review is to determine the risk factors for AF in the dog. Following the PRISMA 2020 guidelines, we conducted a comprehensive search using the Web of Science and Scopus databases for articles reporting on cases of spontaneously occurring AF in dogs. The level of evidence was assessed using the Evidence Quality Grading System of the National Institute of Health. One thousand forty-three studies were initially identified, and twenty of them were included in this systematic review involving 2,359,275 dogs, of which 4807 showed spontaneously occurring AF. Genetics, for the Irish Wolfhound, increased body weight, and left atrial enlargement were the main risk factors for the development of AF in dogs with different cardiac diseases, particularly myxomatous mitral valve disease (MMVD) and dilated cardiomyopathy (DCM). However, some differences were found between these two cardiac diseases regarding additional risk factors. In particular, the presence of congestive heart failure and echocardiographic evidence of increased left atrial pressure or the presence of right atrial enlargement emerged as risk factors in dogs with MMVD or DCM, respectively. Furthermore, significant differences in risk factors were observed between dogs and humans. In particular, advanced age and male sex are not reliable indicators of an increased risk of AF in dogs.

Monocytes Count, NLR, MLR and PLR in Canine Inflammatory Bowel Disease.

This is an observational retrospective study on 85 client-owned dogs, 60 with IBD and 25 clinically healthy dogs. This study aims to assess the clinical relevance of some easy to obtain and cost-effective hematological parameters including red blood cell distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) in dogs with IBD. Comparison of clinical and laboratory parameters between dogs with IBD and control dogs was carried out and the ability to distinguish between these two groups of dogs was evaluated by calculating the area under the receiver-operating characteristic curve (AUCROC). Univariate and multivariable logistic regression analysis estimated the odds ratio (OR) of developing IBD with a 95% confidence interval (CI). MLR and monocytes count had the highest accuracy in facilitating the discrimination of dogs with IBD from control dogs with an AUCROC of 0.839 and 0.787 at the cut-off of >0.14% and >3.7 cells*102/µL, respectively. According to two multivariable models, monocytes count (OR = 1.29; p = 0.016), NLR (OR = 1.80; p = 0.016), and MLR > 0.14 (OR = 8.07; p < 0.001) and PLR > 131.6 (OR = 4.35; p = 0.024) were significant and independent predictors of IBD for models one and two, respectively. Monocytes count and the hematological ratios MLR, NLR, and PLR can be useful in the diagnostic work-up of dogs with IBD.

Factors related to longevity and mortality of dogs in Italy.

Besides its translational value, an improved understanding of dog longevity and mortality is necessary to guide health management decisions, breed selection, and improve dog welfare. In order to analyse the lifespan of dogs in Italy, identify the most common causes of death, and evaluate possible risk factors, anonymised medical records were collected from 9 veterinary teaching hospitals and 2 public health institutions. Data regarding breed, sex, neuter status, age, diagnosis, and mechanism of death were retrieved. Cause of death (COD) was classified by pathophysiologic process (PP) and organ system (OS). Of the 4957 dogs that died between 2004 and 2020 included in the study, 2920 (59.0%) were purebred, 2293 (46.2%) were female, 3005 (60.6%) were intact, 2883 (58.2%) were euthanised. Overall median longevity was 10.0 years. Median longevity was significantly longer for crossbreds, females, neutered dogs, and small-sized breeds. The breeds with the highest median age at death were the Yorkshire terrier, English cocker spaniel, West Highland white terrier, Italian volpino, and Shih Tzu, whilst the American bulldog, English bulldog, American pit bull terrier, Bernese mountain dog and the Maremma and the Abruzzes sheepdog had the lowest median age at death. The most frequent COD by PP was neoplasia (34.0%), which occurred more frequently in large breeds, namely German shepherd, Labrador retriever and Boxer. Degenerative diseases mostly affected small-sized dogs like Miniature pinscher and Dachshund. Regarding the OS involved, diseases of the renal/urinary system were most frequently responsible for COD (15.0%), prevalently degenerative and inflammatory/infectious. Substantial variation in median longevity according to causes of death by PP and OS was observed. These data are relevant for breeders, veterinary practitioners, and owners, to assist breed selection, facilitate early diagnosis, guide choice when purchasing a purebred dog and making health management decisions, and ultimately improve dog welfare.

Red Blood Cell Distribution Width as a Novel Parameter in Canine Disorders: Literature Review and Future Prospective.

Red blood cell distribution width (RDW) is a quantitative laboratory parameter applied for the measurement of anisocytosis and is a reliable and inexpensive method for clinical classification of anemia. An increased RDW reflects a great heterogeneity in the size of red blood cells typical of regenerative and iron-deficiency anemia. In humans, numerous and recent studies have shown a relationship between increased RDW and the risk of morbidity and mortality in patients with various disorders. In particular, a strong association has been established between changes in RDW and the risk of adverse outcome in humans with diseases affecting different organs or systems. Following the human literature, some studies have recently been conducted trying to clarify the clinical role of RDW in various animal disorders, particularly in dogs. In this review, we summarize and critically evaluate the results of the studies based on the measurement of RDW in dogs. We also emphasize the need for further and more extensive studies on the use of this simple and inexpensive parameter in animals.

Prevalence and prognostic role of L wave and selected clinical and echocardiographic variables in dogs with atrial fibrillation.

BACKGROUND: Information regarding the frequency of L waves and their prognostic relevance in dogs with secondary atrial fibrillation (AF) is limited. HYPOTHESIS/OBJECTIVES: To determine whether L waves occur and ascertain their prognostic role, as well as the role of other clinical and echocardiographic variables in dogs with AF. ANIMALS: Fifty-five dogs with AF associated with myxomatous mitral valve disease or dilated cardiomyopathy. METHODS: Retrospective, multicenter observational study. In addition to L waves analysis, other clinical and echocardiographic variables, including type of antiarrhythmic treatment, were evaluated. A survival analysis was performed to test for predictors of cardiac death and all-cause mortality using Cox proportional hazards regression models. RESULTS: L waves were evident in 33/55 dogs (60%, 95% confidence interval [CI] = 47%-72%) but their presence did not influence outcome. Increased left ventricular end-systolic diameter normalized for body weight (LVSDn) was a significant predictor of both cardiac death (hazard ratio [HR] = 4.41, 95% CI = 1.18-16.54; P = .03) and all-cause mortality (HR = 9.39, 95% CI = 2.49-35.32; P < .001). Heart rate assessed during echocardiography (Echo-HR) represented an additional significant predictor of cardiac death (HR = 1.01, 95% CI = 1.00-1.01; P = .04) and all-cause mortality (HR = 1.01, 95% CI = 1.00-1.01; P = .04). CONCLUSIONS AND CLINICAL IMPORTANCE: L waves occurred frequently in dogs with AF, but held no prognostic relevance. Conversely, LVSDn and Echo-HR represented independent predictors of negative outcome in these animals.

Development of an artificial intelligence-based method for the diagnosis of the severity of myxomatous mitral valve disease from canine chest radiographs.

An algorithm based on artificial intelligence (AI) was developed and tested to classify different stages of myxomatous mitral valve disease (MMVD) from canine thoracic radiographs. The radiographs were selected from the medical databases of two different institutions, considering dogs over 6 years of age that had undergone chest X-ray and echocardiographic examination. Only radiographs clearly showing the cardiac silhouette were considered. The convolutional neural network (CNN) was trained on both the right and left lateral and/or ventro-dorsal or dorso-ventral views. Each dog was classified according to the American College of Veterinary Internal Medicine (ACVIM) guidelines as stage B1, B2 or C + D. ResNet18 CNN was used as a classification network, and the results were evaluated using confusion matrices, receiver operating characteristic curves, and t-SNE and UMAP projections. The area under the curve (AUC) showed good heart-CNN performance in determining the MMVD stage from the lateral views with an AUC of 0.87, 0.77, and 0.88 for stages B1, B2, and C + D, respectively. The high accuracy of the algorithm in predicting the MMVD stage suggests that it could stand as a useful support tool in the interpretation of canine thoracic radiographs.

Biological Variation and Reference Change Value of Routine Hematology Measurands in a Population of Managed Bottlenose Dolphins (Tursiops truncatus).

Hematological analyses are particularly useful in assessing a dolphin's health status. However, the creation of appropriate reference intervals for this species is difficult due to the low number of reference individuals. The implementation of individual reference intervals (iRIs) allows researchers to overcome this limitation and, moreover, also consider the within-individual variability. The aims of this study were (1) to evaluate the biological variations in some hematological measurands, including erythrocytes (RBC), hematocrit (Hct), mean cellular volume and hemoglobin content (MCV and MCHC, respectively), RBC distribution width (RDW), leukocytes (WBC), and platelets (PLT); and (2) to calculate the index of individuality (IoI) and reference change value (RCV), which enable the production of iRIs, in healthy managed bottlenose dolphins. Seven dolphins were included, and the results of six hematological exams were analyzed for each animal. Analytical imprecision (CVa), within-dolphin variation (CVi), and between-dolphins variations (CVg) were calculated, and the IoI and RCV were derived for each measurand. All the hematological measurands had intermediate IoI except WBC, for which Iol was low. The calculated RCV ranged from 10.33% (MCV) to 186.51% (WBC). The results reveal that the majority of hematological measurands have an intermediate level of individuality in dolphins, and thus the application of iRIs is appropriate. The calculated RCV can also be applied to other managed dolphins and could be useful in interpreting serial CBC exams.

Serum Protein Concentration and Serum Protein Fractions in Bottlenose Dolphins (Tursiops truncatus) under Human Care Using Agarose Gel Electrophoresis.

Serum protein electrophoresis (SPE) is the most used and reliable method to determine the percentage of serum protein subfractions. The interpretation of the kinetics of total proteins and albumin and globulin fractions is receiving increased attention in wild animals, as well as in domestic animals, due to the possibility of identifying typical pathologic patterns. However, the interpretation of these data had to be performed in light of an appropriate method-and species- specific reference intervals (RIs). In marine mammals, as well as other non-domestic species, specific attention should also be given to the different environment (free ranging vs. human managed) and the associated different exposure to environmental stimuli. The aim of this report was to establish RIs for the serum protein fractions evaluated using agarose gel electrophoresis (AGE) in bottlenose dolphins under human care. Peripheral blood samples were collected from 40 bottlenose dolphins during standard veterinary procedures to evaluate their health status. Total protein concentration was determined using the biuret method while AGE was performed using an automated system. A pooled dolphin's serum sample was used to determine the intra-assay and inter-assay imprecision of AGE. The RIs were calculated using an Excel spreadsheet with the Reference Value Advisor set of macroinstructions. The intra and inter-assay imprecisions were 1.2% and 2.5%, respectively, for albumin; 2.9% and 5.7%, respectively, for α-globulins; 3.8% and 4.0%, respectively, for ß-globulins; and 3.4% and 4.8%, respectively, for γ-globulins. The total protein, albumin, α-globulin, ß-globulin, and γ-globulin concentrations were 65.5 ± 5.4 g/L, 45.5 ± 4.9 g/L, 8.0 ± 1.0 g/L, 5.0 ± 2.0 g/L, and 7.0 ± 2.0 g/L, respectively. We established the RIs for the total protein and serum protein fractions using AGE in bottlenose dolphins under human care.

Risk factors for atrial fibrillation in dogs with dilated cardiomyopathy.

Introduction: Atrial fibrillation secondary to dilated cardiomyopathy (DCM) frequently affects large-breed dogs. The aim of the present study was to identify risk factors for the development of atrial fibrillation in dogs of different breeds with an echocardiographic diagnosis of DCM. Methods: In this multicenter retrospective study, we searched the electronic databases of five cardiology referral centers for dogs with an echocardiographic diagnosis of DCM. A comparison of clinical and echocardiographic variables was performed between dogs developing atrial fibrillation and those not developing atrial fibrillation and the ability to distinguish between these two groups of dogs was evaluated by receiver operating characteristic curve analysis. Univariate and multivariable logistic regression analysis estimated the odds ratio (OR) with 95% confidence interval (CI) of developing atrial fibrillation. Results: We included 89 client-owned dogs with occult and overt echocardiographic DCM. Of these, 39 dogs (43.8%) had atrial fibrillation, 29 dogs (32.6%) maintained a sinus rhythm, and 21 dogs (23.6%) showed other cardiac arrhythmias. Left atrial diameter had high accuracy (area under the curve = 0.816, 95% CI = 0.719-0.890) to predict the development of atrial fibrillation at the cut-off of >4.66 cm. After multivariable stepwise logistic regression analysis, only increased left atrial diameter (OR = 3.58, 95% CI = 1.87-6.87; p < 0.001) and presence of right atrial enlargement (OR = 4.02, 95% CI = 1.35-11.97; p = 0.013) were significant predictors of atrial fibrillation development. Discussion: Atrial fibrillation is a common complication of DCM in the dog and is significantly associated with increased absolute left atrial diameter and right atrial enlargement.

Malassezia overgrowth in dogs in northern Italy: frequency, body distribution, clinical signs and effects of pharmacologic treatments.

The present study describes Malassezia populations in clinically healthy dogs (HD) and dogs with Malassezia overgrowth (MO), and evaluates the correlation with clinical signs and previous treatments. Thirteen clinically HD and 84 dogs with MO were enrolled. Clinical history and previous treatments were recorded. After a complete physical and dermatological examination, Canine Atopic Dermatitis Extent and Severity Index_03 scores were calculated. Samples for cytology and mycological cultures were obtained from four body regions and from skin lesions. Malassezia overgrowth was diagnosed by cytology. A global score (GS) for quantitative evaluation of the population of Malassezia was calculated. In dogs with MO, the highest frequency of yeast detection was found in skin lesions (82%, P < 0.001). Sum of GS (GSs) obtained from dogs with MO (68, 0­621) was significantly higher compared to those of HD (3, 0­48, P < 0.001). GSs in dogs previously treated with antibiotics (312.5, 30­975) was significantly higher compared to those of dogs that not have received antibiotics (80, 0­975, P = 0.015). No difference was found between dogs treated and those not treated with steroids.

Radiographic features of cardiogenic pulmonary oedema in cats with left-sided cardiac disease: 71 cases.

OBJECTIVES: The aims of this study were to describe the radiographic features of cardiogenic pulmonary oedema (CPE) in a large group of cats with left-sided cardiac disease, and to determine the association between the radiographic features of CPE and the underlying cardiac disease. METHODS: Thoracic radiographs of cats with CPE and echocardiographic evidence of left-sided cardiac disease and left atrial enlargement (LAE) were reviewed, and cardiac silhouette, pulmonary vessels and pulmonary parenchyma evaluation were performed. Interstitial and/or alveolar patterns were classified according to their distribution (ie, diffuse, multifocal or focal) and location (ie, craniodorsal, cranioventral, caudodorsal, caudoventral and perihilar). A Student's t-test and Mann-Whitney U-test, or the two-proportion z-test, were used to compare continuous or categorical variables, respectively, between cats affected by the two most represented cardiac diseases, namely hypertrophic cardiomyopathy (HCM) and restrictive cardiomyopathy (RCM). RESULTS: Seventy-one cats were included; among them, 46 (64.7%) and 13 (18.3%) had presented for HCM and RCM, respectively. Subjective and objective cardiomegaly, and subjective and objective LAE were detected in 97.2% and 91.9% of cats and in 80.3% and 40.6% of cats, respectively. Pulmonary artery abnormalities, in particular caudal pulmonary artery dilation, were found in 77.5% of cats. Pulmonary artery to pulmonary vein ratio = 1 was found in 71.8% and 55% cats on right lateral and ventrodorsal or dorsoventral views, respectively. Interstitial (57.8%) and mixed interstitial-alveolar (38%) pattern, multifocal (84.5%) and symmetrical (75%) distribution with prevalent ventrocaudal (65.6% of cats) and ventrocranial (60.9% of cats) locations were most frequently observed. No difference was found for any of these radiographic features between cats with HCM and RCM. CONCLUSIONS AND RELEVANCE: Moderate-to-severe cardiomegaly and LAE, caudal pulmonary artery and vein dilation, as well as a ventral, multifocal and symmetrical interstitial pulmonary pattern, were the main radiographic features of CPE in evaluated cats. Underlying cardiac disease did not influence the aforementioned radiographic features.

Prognostic Role of Red Cell Distribution Width and Other Routine Clinico-Pathological Parameters in Dogs with Acute Pancreatitis.

This study aimed to assess the prognostic value of red cell distribution width (RDW) RDW-to-calcium ratio (RDW/Ca), neutrophils-to-lymphocytes ratio (N/L), platelets-to-lymphocytes ratio (P/L) and other easy to obtain and inexpensive hematological and biochemical parameters in dogs with acute pancreatitis. This is a multicenter, retrospective cohort study including 70 client-owned dogs. The accuracy of clinical and laboratory variables to predict short-term death (i.e., dead by 14 days) was tested by calculating the area under the receiver-operating characteristic curve (AUC). Independent predictors of death were identified using the multivariable Cox proportional hazards regression model. The survival rate was 72.9% (51 dogs) and 19 dogs died within 14 days of admission from AP. RDW and blood urea nitrogen (BUN) had good accuracy to predict short-term dead with AUC of 0.74 and 0.70 at the cut-off of >12.7% and >42 mg/dL, respectively. According to the multivariable model, RDW (hazard ratio and 95% confidence interval [HR, 95% CI] = 5.08, 95% CI = 1.14−22.67; p = 0.03), BUN (HR = 1.00, 95% CI = 1.00−1.01; p < 0.01) and bilirubin (HR = 2.46, 95% CI = 1.38−4.39; p < 0.01) were independent predictors of death. The results indicate that RDW, BUN and bilirubin are useful predictors of short-term death in dogs with acute pancreatitis.

Left Pulmonary Artery Coarctation Associated with Pneumonia and Pulmonary Hypertension in a Cat.

A five-month-old European shorthair female kitten was referred because of recurrent episodes of respiratory distress. Results of physical examination, thoracic radiography, and echocardiography led to a presumptive diagnosis of severe precapillary pulmonary hypertension (PH) and interstitial pneumonia associated with right-sided cardiac remodeling. The cat rapidly died because of respiratory insufficiency. Pulmonary and cardiovascular pathological findings evidenced left pulmonary artery coarctation, severe right-sided cardiac hypertrophy, and bilateral pneumonia. This is the first report of pulmonary artery coarctation associated with pneumonia and PH in a cat.

Red Cell Distribution Width Has a Negative Prognostic Role in Dogs with Myxomatous Mitral Valve Disease.

Red cell distribution width (RDW) is a quantitative measurement of anisocytosis. This hematological parameter is an important prognostic biomarker for different cardiovascular disorders in humans but its influence on survival has been poorly investigated in dogs with cardiovascular disease. The RDW and various clinical, complete blood count, serum biochemical and echocardiographic variables were retrospectively investigated in 146 client-owned dogs with myxomatous mitral valve disease (MMVD) at various disease stages, with or without concurrent diseases and treatment. Laboratory variables, including RDW, urea, and white blood cell (WBC), in addition to the echocardiographic variable left atrium to aorta ratio were found to be independent predictors of all-cause mortality at six months in a multivariable Cox proportional hazards regression model. In particular, the hazard ratio of RDW was 1.203 (95% confidence interval = 1.045-1.384; p = 0.010). The negative effect of increased RDW on outcome was confirmed using Kaplan-Meier curve analysis. The results of this study indicate that RDW acted as an independent predictor of negative outcome in dogs with MMVD.

Lorenz Plot Analysis in Dogs with Sinus Rhythm and Tachyarrhythmias.

The Lorenz plot (LP), a graphical representation of heart rate variability, has been poorly studied in dogs to date. The present study aimed to describe the graphic features of LP in dogs with sinus rhythm (SR) and tachyarrhythmias, and to analyze the usefulness of its pattern recognition. One hundred and nineteen canine Holter recordings were retrospectively evaluated. Cardiac rhythms were classified as: SR; SR with frequent (>100) premature ectopies (atrial, SR-APCs; ventricular, SR-VPCs; atrial and ventricular, SR-APCs-VPCs); atrial fibrillation (AF); and AF with frequent VPCs (AF-VPCs). Lorenz plots were studied qualitatively and quantitatively, and classified by distinct LP patterns (LPPs). Repeatability and reproducibility of LPP classification and diagnostic value were determined. Recordings included: 48 SR, 9 SR-APCs, 35 SR-VPCs, 5 SR-APCs-VPCs, 4 AF, and 18 AF-VPCs. Ten LPPs were identified: comet (n = 12), torpedo (n = 3), Y-shaped (n = 6), diamond (n = 10), diamond with a central silent zone (n = 17), double side-lobe (DSL) (n = 47), triple side-lobe (n = 1), quadruple side-lobe (n = 2), fan (n = 18), and fan with DSL (n = 3). Repeatability and reproducibility of LPP classification were excellent. The DSL pattern was both highly sensitive (91.3%) and specific (94.5%) for SR with frequent premature ectopies, either APCs, or VPCs, or both. The remaining LPPs had lower diagnostic value (high specificity but low sensitivity). Distinct rhythms imprint distinct and reproducible LPPs in dogs. The majority of canine LPPs are specific but insensitive indicators of SR and tachyarrhythmias.

Correction: Effect of temperature variation on hospital admissions and outcomes in dogs with myxomatous mitral valve disease and new onset pulmonary edema.

[This corrects the article DOI: 10.1371/journal.pone.0227807.].

Plasmatic Dimethylarginines in Dogs With Myxomatous Mitral Valve Disease.

Plasmatic dimethylarginines, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) are considered biomarkers of endothelial and renal dysfunction, respectively, in humans. We hypothesize that plasmatic concentration of dimethylarginines in dogs with myxomatous mitral valve disease (MMVD) is influenced by heart disease stage. Eighty-five client-owned dogs with MMVD, including 39, 19, and 27 dogs in ACVIM stages B1, B2, and C+D, respectively, and a control group of 11 clinically healthy dogs were enrolled. A prospective, multicentric, case-control study was performed. Each dog underwent a complete clinical examination, arterial blood pressure measurement, thoracic radiography, six-lead standard electrocardiogram, transthoracic echocardiography, CBC, biochemical profile, and urinalysis. Plasmatic concentration of dimethylarginines was determined through high-performance liquid chromatography coupled with tandem mass spectrometry. Median ADMA was significantly increased in dogs of group C+D (2.5 µmol/L [2.1-3.0]) compared to those of group B1 (1.8 µmol/L [1.6-2.3]; p < 0.001) and healthy dogs (1.9 µmol/L [1.7-2.3]; p = 0.02). Median SDMA was significantly increased in dogs of group C+D (0.7 µmol/L [0.5-0.9]) compared to those of groups B1 (0.4 µmol/L [0.3-0.5]; p < 0.001), B2 (0.4 µmol/L [0.3-0.6]; p < 0.01), and the control group (0.4 µmol/L [0.35-0.45]; p = 0.001). In the final multivariable analysis, ADMA and SDMA were significantly associated with left atrium to aorta ratio (p < 0.001), and creatinine (p < 0.001), respectively. Increased plasmatic concentrations of dimethylarginines suggest a possible role as biomarkers of disease severity in dogs with decompensated MMVD.

Diagnostic Imaging of Cardiovascular Disease in Small Animals.

Cardiovascular disease (CVD) has always been an important field of application for diagnostic imaging in small animal practices and, vice-versa, diagnostic imaging has greatly expanded the diagnostic capabilities of veterinary clinicians dealing with CVD [...].

Symmetric dimethylarginine in dogs with myxomatous mitral valve disease at various stages of disease severity.

Symmetric dimethylarginine (SDMA) is a serum biomarker of renal damage in dogs. Moreover, SDMA concentration is an independent predictor of development of severe heart failure (HF) in humans with cardiac disease. This study evaluates whether the serum concentration of SDMA in dogs with myxomatous mitral valve disease (MMVD) is influenced by the severity of heart disease, pulmonary hypertension (PH) and treatment of HF. A total of 99 client-owned dogs were included in this retrospective case-control study; 78 dogs were affected by MMVD and classified according to the American College of Veterinary Internal Medicine (ACVIM) guidelines, and 21 were healthy controls. For each dog, history, physical examination, complete blood count, biochemical profile, thoracic radiography, 6-lead standard electrocardiogram and trans-thoracic echocardiography were available. Comparisons were performed between groups of dogs belonging to different ACVIM stages and between dogs with and without PH. The median SDMA concentration was neither significantly different among groups of dogs in different disease stages (overall P = 0.010), nor among dogs with MMVD, nor between those with [14.5 µg/dl (10.5-18.8)] and without PH [13 µg/dl (9-17.2)] (P = 0.295). The concentration of SDMA did not differ between dogs when considering the combined effect of the ACVIM group and cardiac treatment (overall P = 0.486). Furthermore, no correlation was found between SDMA concentration and radiographic and echocardiographic parameters associated with increased MMVD severity. In conclusion, this study failed to demonstrate the presence of renal impairment in dogs with MMVD, and the increase in renal parameters in some dogs in the more advanced stage of MMVD could be attributed to pre-renal azotemia.

Effect of temperature variation on hospital admissions and outcomes in dogs with myxomatous mitral valve disease and new onset pulmonary edema.

The effect of seasonal variation on hospital admissions and outcomes in humans with cardiovascular disease and congestive heart failure (CHF) has been described. This study evaluates the effect of temperature variation on admissions and outcomes in dogs with myxomatous mitral valve disease (MMVD) and first onset CHF. Ninety-three client-owned dogs with MMVD and a first occurrence of pulmonary edema were included in this retrospective clinical cohort study. Recorded clinical and echocardiographic variables were accumulated and analyzed with dogs allocated into groups in a temperature-wise manner that considered the mean of the average (Tave) and maximum ambient temperature (Tmax) of the 14 days preceding hospital admission. A survival analysis was also performed. No difference was found in the percentage of dogs decompensating in three different temperature periods (i.e., cold, intermediate, and hot temperature) according to both Tave and Tmax. Dogs developing CHF during the intermediate temperatures according to Tmax died earlier from cardiac-related causes (median survival time 280 days, 95% CI = 147-486 days) compared to those decompensating during hot temperatures (median survival time 518 days, 95% CI = 344-819 days, P = 0.039). However, an effect of the ambient temperature on survival was not confirmed by Cox proportional hazard analysis. In conclusion, this study failed to show that ambient temperature has an effect on the first occurrence of CHF and outcomes in dogs with MMVD.