The vertebral right heart index: A new radiographic method to assess right heart enlargement in dogs.

In veterinary medicine, the radiographic assessment of right heart enlargement (RHE) is essentially subjective. The aim of this study was to evaluate the vertebral right heart index (VRHi) as a new quantitative radiographic method to detect RHE in dogs. This was a multicenter, retrospective, observational study, including dogs with RHE and control dogs. All dogs had to have a thoracic radiographic study and a complete echocardiography on the same day. Right heart enlargement was defined as the presence of right atrial enlargement, right ventricular enlargement, and/or hypertrophy based on echocardiography. For the radiographic study, all the radiographic views available for each case were considered for measurement: right lateral (RL), left lateral (LL), ventrodorsal (VD), and dorsoventral (DV). The VRHi was measured using LL, RL, VD, and DV views. A total of 204 dogs were included: 91 dogs with RHE and 113 control dogs. The VRHi (RL), the VRHi (LL), and the VRHi (VD) were significantly greater in dogs with RHE compared with controls (P < .0001). The best diagnostic accuracy was observed for VRHi (LL) (area under the curve [AUC] 0.86, P < .0001; cutoff ≥ 3.5 vertebrae, sensitivity [Se] 71%, specificity [Sp] 89%), followed by VRHi (RL) (AUC 0.85, P < .0001; cutoff ≥ 3.5 vertebrae, Se 68%, Sp 86%) and VRHi (VD) (AUC 0.80, P = .0004; cutoff ≥ 3.0 vertebrae, Se 57%, Sp 95%). In conclusion, the lateral VRHi in LL and RL and the VD VRHi could represent useful radiological tools for the detection of RHE in dogs.

Accuracy of the modified vertebral heart score and the cardio-vertebral ratio for radiographic evaluation of cardiomegaly in ferrets.

Thoracic radiography is commonly used to assess the size of the heart and diagnose cardiac disease in ferrets. Several standardized radiographic heart size indicators have been introduced in this species and values in healthy ferrets have been reported. To date, none of these indicators has been tested in ferrets with cardiac disease. The aim of this prospective and retrospective, analytical observational design study was to assess the accuracy of the modified vertebral heart score (mVHS) and the cardio-vertebral ratio (CVR) in the radiographic detection of cardiomegaly in ferrets. Thoracic radiographs of 24 ferrets with confirmed heart diseases, 22 ferrets with non-cardiac diseases and normal-sized hearts on echocardiogram, and 24 healthy ferrets were mixed and examined by three independent and blinded radiologists who measured mVHS and CVR in right lateral (RL) and ventrodorsal (VD) radiographs. For all readers, ferrets with cardiac disease had significantly higher mVHS and CVR than ferrets without cardiac disease on echocardiography. Optimal cut-points for predicting cardiac enlargement were 6.25 vertebrae and 7.25 vertebrae for RL-mVHS and VD-mVHS, and 1.58 and 1.80 for RL-CVR and VD-CVR, respectively. Using these cut-points, the accuracy was good for indicators measured in RL radiographs (92.9% for RL-mVHS; 91.4% for RL-CVR) and moderate for indicators measured in VD radiographs (88.6% for VD-mVHS; 85.7% for VD-CVR). Findings supported the use of mVHS and CVR for evaluating the size of the heart in diseased ferrets, with caution in values interpretation when pericardial fat prevents precise delineation of the cardiac silhouette contour especially on VD radiographs.

Heart failure in a cat due to hypertrophic cardiomyopathy phenotype caused by chronic uncontrolled hyperthyroidism.

A 16-year-old castrated male Persian cat was presented with weight loss, anorexia and dyspnoea. Tachycardia and tachypnoea were observed upon presentation. The cat was previously diagnosed with hyperthyroidism and left ventricular hypertrophy and received methimazole, but was subsequently not followed up and treated appropriately. Thoracic radiography revealed mild pleural effusion, interstitial lung pattern, moderate cardiomegaly and moderate-to-severe dilation of the pulmonary artery and pulmonary vein. On echocardiography, the left ventricular hypertrophy, identified earlier, shoed partial regression. Therefore, the previous myocardial hypertrophy was diagnosed as a hypertrophic cardiomyopathy phenotype related to hyperthyroidism. ST-segment elevation was identified on electrocardiography, and the thyroid profile examination revealed increased total thyroxine and free thyroxine and decreased thyroid-stimulating hormone levels, suggesting myocardial injury and uncontrolled hyperthyroidism, respectively. In addition, normal N-terminal pro-B-type natriuretic peptide and high cardiac troponin I levels were found. Based on these findings, the observed congestive heart failure was considered as a sequel of myocardial injury caused by uncontrolled hyperthyroidism. Clinical signs resolved after intravenous administration of furosemide and butorphanol, oxygen supply and thoracocentesis. Furosemide and pimobendan were additionally administered, and the cat was discharged. This case demonstrates that myocardial damage due to chronic uncontrolled hyperthyroidism may cause heart failure in cats.

Unusual diagnosis of feline cardiac lymphoma using cardiac needle biopsy.

BACKGROUND: Cardiac tumors in cats are relatively rare, with lymphoma accounting for more than half of all cases. However, feline cardiac lymphoma is often diagnosed post-mortem, and it is difficult to diagnose while the cat is still alive. It is the first report of a direct, rather than estimative, diagnosis with cardiac needle biopsy of a living cat with cardiac lymphoma. CASE PRESENTATION: A 3-year-old domestic short-haired male cat experienced loss of energy and loss of appetite. Thoracic radiography and transthoracic echocardiography showed cardiomegaly with slight pleural effusion and cardiac tamponade due to pericardial effusion, respectively. In addition, partial hyperechoic and hypertrophy of the papillary muscle and myocardium were observed. Blood test showed an increase in cardiac troponin I levels. Pericardial fluid, removed by pericardiocentesis, was analyzed; however, the cause could not be determined. With the owner's consent, pericardiectomy performed under thoracotomy revealed a discolored myocardium. Cardiac needle biopsy was performed with a 25G needle, and a large number of large atypical lymphocytes were collected; therefore, a direct diagnosis of cardiac lymphoma was made. Pathological examination of the pericardium diagnosed at a later date revealed T-cell large cell lymphoma. The cat underwent chemotherapy followed by temporary remission but died 60 days after the diagnosis. Postmortem, two-dimensional speckle-tracking echocardiography (data when alive) revealed an abnormal left ventricular myocardial deformation, which corresponded to the site of cardiac needle biopsy. CONCLUSIONS: This rare case demonstrates that cardiac lymphoma should be added to the differential diagnosis in cats with myocardial hypertrophy and that the diagnosis can be made directly by thoracotomy and cardiac needle biopsy. In addition, the measurement of cardiac troponin I levels and local deformation analysis of the myocardium by two-dimensional speckle-tracking echocardiography may be useful in the diagnosis of cardiac tumors.

A case of a complete atrioventricular canal defect in a ferret.

BACKGROUND: Atrioventricular canal defect is a rare congenital disorder of the heart and describes the presence of an atrial septal defect, a variable presentation of ventricular septal alterations including ventricular septal defect malformations in the mitral and tricuspid valves. The defect has been described in human beings, dogs, cats, pigs, and horses. CASE PRESENTATION: This paper describes the case of a complete atrioventricular canal defect in a four-year-old intact male pet ferret (Mustela putorius furo), which was presented due to posterior weakness, ataxia, and decreased appetite. A loud systolic murmur, dyspnea, and hind limb paraparesis were detected during the clinical examination. Thoracic radiographs showed generalized cardiomegaly and lung edema. ECG showed sinus rhythm with prolonged P waves and QRS complexes. Echocardiography showed a large atrial septal defect, atrioventricular dysplasia, and a ventricular septal defect. Palliative treatment with oxygen, furosemide, spironolactone, enalapril, diltiazem, and supportive care was chosen as the therapy of choice. The ferret recovered gradually during hospitalization. A follow-up examination at three and six months showed stabilization of cardiac function. CONCLUSIONS: To the authors knowledge, this is the first time an atrioventricular canal defect has been described in a pet ferret.

Evaluation of radiographic predictors of left heart enlargement in dogs with known or suspected cardiovascular disease.

Radiographic assessment of heart size is important for clinical management of dogs with cardiovascular disease (CVDz). We sought to compare the ability of vertebral heart size (VHS), vertebral left atrial size (VLAS), and radiologists' assessment of left atrial size (RadLAE) to predict echocardiographic left atrial size (EchoLAE), an important marker of left heart disease severity. We also compared the ability of VHS and VLAS to predict echocardiographic criteria for ACVIM stage B2 (EchoB2) in dogs with myxomatous mitral valve disease (MMVD). This prospective observational study enrolled 183 dogs with known or suspected CVDz that had an echocardiographic examination and thoracic radiographs obtained within 24 h. Compared to increased VHS, VLAS >2.3 was a more accurate predictor of EchoLAE (P = .002). VLAS >2.3 and RadLAE (both P <.0001) were independently associated with EchoLAE but VHS was not (P = .45). Optimal cutoffs for VLAS and VHS to predict EchoLAE were >2.3 vertebrae (sensitivity [Sn] = 90.3%, specificity [Sp] = 73.6%) and >11.1 vertebrae (Sn = 75.8%, Sp = 76.0%), respectively. Diagnostic accuracy of VLAS (AUC 0.84, 95% CI 0.73-0.92) and VHS (AUC 0.78, 95% CI 0.66-0.88) to predict EchoB2 in dogs with subclinical MMVD (n = 64) were not significantly different (P = .17). Results demonstrate that VLAS and RadLAE were superior indicators of EchoLAE compared to VHS in dogs with known or suspected CVDz. Both VLAS and VHS are useful predictors of EchoB2 in dogs with subclinical MMVD. When echocardiography is unavailable, VLAS represents a useful radiographic measurement to aid clinical management of dogs with known or suspected CVDz.

Interpretation of cardiac chamber size on canine thoracic radiographs is limited and may result in the false identification of right-sided cardiomegaly in the presence of severe left-sided cardiomegaly.

Qualitative assessment of individual cardiac chamber enlargement on thoracic radiographs was assessed using echocardiography as the gold standard in dogs. Using this method, the presence of severe left-sided cardiomegaly was hypothesized to contribute to the false identification of right-sided cardiomegaly on radiographs. 175 dogs with three-view thoracic radiographs were retrospectively included in this diagnostic accuracy study if echocardiography was done within 24 h, and no rescue therapy was provided in the interim. All radiographic studies were reviewed by two groups of five board-certified veterinary radiologists with greater and less than 10 years of experience for grading of cardiac chamber enlargement as normal or mildly, moderately, or severely enlarged. The agreement, sensitivity, and specificity of the radiologists' interpretation of cardiac chamber size on thoracic radiographs to measured echocardiographic grades were evaluated. A total of 147 cases had complete echocardiographic data available for analysis. Intragroup agreement was moderate for the evaluation of left atrial enlargement and slight to fair for all other cardiac chambers. Between the mode of the radiologists' responses in the two groups and the echocardiographic grades, there was slight agreement for all cardiac chambers with higher severity grades reported using echocardiography. When moderate to severe left-sided cardiomegaly was identified on echocardiography, the sensitivity, specificity, and accuracy of radiographs were low, identifying dogs with radiographic evidence of right-sided cardiomegaly in the absence of corresponding right-sided cardiomegaly on echocardiography. Therefore, thoracic radiographs should be used with caution for the evaluation of cardiac chamber enlargement, particularly in the presence of severe left-sided cardiomegaly.

A radiographic study of breed-specific vertebral heart score and vertebral left atrial size in Chihuahuas.

Although echocardiography is the gold standard for the diagnosis of cardio-structural disease, thoracic radiography is a rapid, cost-effective, and widely accessible method for evaluating cardiac size in dogs. The vertebral heart score (VHS) and the vertebral left atrial size (VLAS) are established as objective measures of cardiomegaly on thoracic radiographs. However, several studies have shown significant variations in the VHS among different breeds. The Chihuahua is predisposed to both congenital and acquired cardiac diseases. The aim of this prospective, single-center, cross sectional study was thus to evaluate the VHS and the VLAS in healthy adult Chihuahua dogs. A total of 30 Chihuahuas were included. The VHS values in our sample population of Chihuahuas were 10.0 ± 0.6 (95% range, 8.9-11.0). This was significantly greater than the canine reference value of 9.7 ± 0.5 established by Buchanan and Bücheler (P = .002). The VLAS of Chihuahuas in our study was 1.8 ± 0.2 (95% range, 1.3-2.1). This was significantly lower than the values previously reported by Malcolm et al (2.07 ± 0.25; P = .0004). The VHS and the VLAS were not influenced by sex, body weight, short or long hair, and body condition score in normal Chihuahuas. Our results indicated that breed-specific reference values for radiographic VHS and VLAS are needed. In Chihuahuas, the values found in this study can be used as a normal reference in order to help avoid overinterpretation of cardiomegaly in these dogs.

Supplemental 25-hydroxycholecalciferol Alleviates Inflammation and Cardiac Fibrosis in Hens.

Broiler breeder hens with efficient feed conversion rate under restricted feed intake (R-hens) or allowed unlimited access to feed (Ad-hens) progressed with cardiac functional failure and suffered early sudden death. A supplement of 69 µg 25-hydroxycholecalciferol (25-OH-D3)/kg feed improved heart health and rescued livability in both R- and Ad-hens throughout laying stage (26-60 wks). Improvements occurred through cardiac hypertrophic remodeling, reduced arrhythmias, and pathological cues. Here, we further demonstrated consistently decreased circulating and cardiac IL-6 and IL-1ß levels in conjunction with reduced cardiac chemoattraction and leukocyte infiltration by 25-OH-D3 in Ad-hens and in R-hens at later time points (35 and 47 wks) (p < 0.05). Supplemental 25-OH-D3 also ameliorated cardiac fibrosis, endoplasmic reticulum (ER) stress, and autophagy, mostly in Ad-hens, as both collagen content and expression of COL3A1, as well as CCAAT box binding enhancer homologous protein (CHOP) and activating transcription factor 6 (ATF6), were consistently decreased, and suppression of microtubule-associated protein 1 light Chain 3 beta (LC3B) and Sequestosome 1 (SQSTM1) was rescued at 35 and 47 wks (p < 0.05). Vitamin D receptor-NF-κB signaling was shown to mediate these beneficial effects. The present results demonstrate that ER stress and autophagic processes along the sequence from inflammation to fibrotic changes contribute to pathological cardiac remodeling and functional compromise by Ad-feed intake. 25-OH-D3 is an effective anti-inflammatory and anti-fibrotic supplement to ameliorate cardiac pathogenesis in broiler breeder hens.

Artificial intelligence evaluating primary thoracic lesions has an overall lower error rate compared to veterinarians or veterinarians in conjunction with the artificial intelligence.

To date, deep learning technologies have provided powerful decision support systems to radiologists in human medicine. The aims of this retrospective, exploratory study were to develop and describe an artificial intelligence able to screen thoracic radiographs for primary thoracic lesions in feline and canine patients. Three deep learning networks using three different pretraining strategies to predict 15 types of primary thoracic lesions were created (including tracheal collapse, left atrial enlargement, alveolar pattern, pneumothorax, and pulmonary mass). Upon completion of pretraining, the algorithms were provided with over 22 000 thoracic veterinary radiographs for specific training. All radiographs had a report created by a board-certified veterinary radiologist used as the gold standard. The performances of all three networks were compared to one another. An additional 120 radiographs were then evaluated by three types of observers: the best performing network, veterinarians, and veterinarians aided by the network. The error rates for each of the observers was calculated as an overall and for the 15 labels and were compared using a McNemar's test. The overall error rate of the network was significantly better than the overall error rate of the veterinarians or the veterinarians aided by the network (10.7% vs 16.8% vs17.2%, P = .001). The network's error rate was significantly better to detect cardiac enlargement and for bronchial pattern. The current network only provides help in detecting various lesion types and does not provide a diagnosis. Based on its overall very good performance, this could be used as an aid to general practitioners while waiting for the radiologist's report.

Pilot study: Application of artificial intelligence for detecting left atrial enlargement on canine thoracic radiographs.

Although deep learning has been explored extensively for computer-aided medical imaging diagnosis in human medicine, very little has been done in veterinary medicine. The goal of this retrospective, pilot project was to apply the deep learning artificial intelligence technique using thoracic radiographs for detection of canine left atrial enlargement and compare results with those of veterinary radiologist interpretations. Seven hundred ninety-two right lateral radiographs from canine patients with thoracic radiographs and contemporaneous echocardiograms were used to train, validate, and test a convolutional neural network algorithm. The accuracy, sensitivity, and specificity for determination of left atrial enlargement were then compared with those of board-certified veterinary radiologists as recorded on radiology reports. The accuracy, sensitivity, and specificity were 82.71%, 68.42%, and 87.09%, respectively, using an accuracy driven variant of the convolutional neural network algorithm and 79.01%, 73.68%, and 80.64%, respectively, using a sensitivity driven variant. By comparison, accuracy, sensitivity, and specificity achieved by board-certified veterinary radiologists was 82.71%, 68.42%, and 87.09%, respectively. Although overall accuracy of the accuracy driven convolutional neural network algorithm and veterinary radiologists was identical, concordance between the two approaches was 85.19%. This study documents proof-of-concept for application of deep learning techniques for computer-aided diagnosis in veterinary medicine.

Effect of expiratory phase for radiographic detection of left heart enlargement in dogs with mitral regurgitation.

Radiography is a standard diagnostic test for characterizing left heart enlargement in dogs however limited information is available on the effects of respiratory phases. This prospective and retrospective method comparison study investigated the respiratory effect on the size and shape of the left heart in dogs to determine the usefulness of expiratory radiographs to detect enlargements in the left atrium (LA) and left ventricle (LV). Thoracic radiographs taken at full inspiration and expiration were evaluated in 20 normal beagles and 100 dogs diagnosed with mitral regurgitation (MR). Vertebral heart score (VHS), vertebral left atrial size, elevation of the carina, and dorsal bulging of LA on lateral view and lateral bulging of the left auricular appendage and LV on ventrodorsal view were assessed. In normal dogs, there were no significant differences in the evaluative factors between inspiration and expiration. In dogs with MR, VHS did not change according to respiration. However, bulging of the LA, left auricular appendage, and LV had sharp margin during expiration compared with inspiration. The expiratory radiographic finding of LA bulging had a higher correlation with the LA to aorta ratio compared with LA bulging in the inspiratory radiography. Using a LA to aorta echocardiographic ratio greater than 1.5 as the gold standard, the radiographic sensitivity for LA enlargement was higher during expiration than inspiration. These findings of our study indicated that expiratory radiography can be helpful to support the detection of left heart enlargement, although it can overestimate LA enlargement in dogs with MR.

Chronic Pressure Overload Induces Cardiac Hypertrophy and Fibrosis via Increases in SGLT1 and IL-18 Gene Expression in Mice.

Increased gene expression levels of sodium-glucose cotransporter 1 (SGLT1) are associated with hypertrophic and ischemic cardiomyopathy. However, it remains unclear whether chronic pressure overload increases SGLT1 expression, which in turn induces hypertrophic cardiomyopathy. We hypothesized that pressure overload could increase SGLT1 gene expression, leading to the development of hypertrophic cardiomyopathy.To create pressure overload-induced cardiomyopathy, transverse aortic constriction (TAC) was performed in SGLT1-deficient (SGLT1-/-) and wild-type (WT) mice. Six weeks after surgery, all mice were investigated. We observed a reduction of left ventricular fractional shortening and left ventricular dilatation in TAC-operated WT but not in TAC-operated SGLT1-/- mice. SGLT1, interleukin 18, connective tissue growth factor, and collagen type 1 gene expression levels were increased in TAC-operated WT mouse hearts compared with that of sham-operated WT mouse hearts. Moreover, heart/body weight ratio and ventricular interstitial fibrosis were increased in TAC-operated WT mice compared with that of sham-operated WT mice. Interestingly, these factors did not increase in TAC-operated SGLT1-/- mice compared with that of sham-operated WT and SGLT1-/- mice. Phenylephrine, an adrenergic α1 receptor agonist, caused cardiomyocyte hypertrophy in neonatal WT mouse hearts to a significantly larger extent than in neonatal SGLT1-/- mouse hearts.In conclusion, the results indicate that chronic pressure overload increases SGLT1 and IL-18 gene expressions, leading to the development of hypertrophic cardiomyopathy. These results make SGLT1 a potential candidate for the therapeutic target for hypertension-induced cardiomyopathy.

Prevalence of Trypanosoma cruzi and organ alterations in Virginia opossums (Didelphis virginiana) from western Mexico - short communication.

Small populations of Virginia opossum (Didelphis virginiana) in western Mexico are endangered by hunting and natural predators as well as by different kinds of diseases. After two serological analyses using Serodia® latex particle agglutination and indirect haemagglutination (IHA) tests, 35 (53.03%) of 66 collected opossums in two small towns in western Mexico were positive for the presence of Trypanosoma cruzi. Twenty-eight of the 35 seropositive opossums had pathological lesions: 11 had changes in only one organ, 13 in two organs, and four had pathological changes in three organs. Splenomegaly was the most common finding in the examined opossums, followed by hepatomegaly. These potentially fatal pathological changes could contribute to the scarcity of the opossum population, even leading to the extinction of this species in western Mexico.

A valentine-shaped cardiac silhouette in feline thoracic radiographs is primarily due to left atrial enlargement.

Conflicting information has been published regarding the cause of a valentine-shaped cardiac silhouette in dorsoventral or ventrodorsal thoracic radiographs in cats. The purpose of this retrospective, cross-sectional study was to test the hypothesis that the valentine shape is primarily due to left atrial enlargement. Images for cats with a radiographic valentine-shaped cardiac silhouette and full echocardiography examination were retrieved and independently reviewed. A subjective scoring system was used to record severity of radiographic valentine shape. Subjective radiographic evidence of left atrial enlargement in a radiographic lateral projection and a final diagnosis based on medical records were also recorded. A total of 81 cats met inclusion criteria. There was a strong positive correlation (P < 0.001) between echocardiographic left atrial size and severity of radiographic valentine shape. There was no effect of echocardiographic right atrial size on the severity of valentine shape, except when concurrent with severe left atrial enlargement. In this situation, right atrial enlargement increased the likelihood of observing a severe valentine shape. There was no effect of right atrial enlargement on the shape of the cardiac silhouette when left atrial enlargement was absent or only mild to moderate. There was no correlation between the category of final diagnosis of cardiac disease and the severity of valentine shape. Findings from this study supported the hypothesis that a valentine-shaped cardiac silhouette in radiographs is due primarily to left atrial enlargement in cats, with right atrial enlargement only impacting the shape if concurrent with severe left atrial enlargement.

PULMONARY ARTERIAL DISEASE ASSOCIATED WITH RIGHT-SIDED CARDIAC HYPERTROPHY AND CONGESTIVE HEART FAILURE IN ZOO MAMMALS HOUSED AT 2,100 M ABOVE SEA LEVEL.

Subacute and chronic mountain sickness of humans and the related brisket disease of cattle are characterized by right-sided congestive heart failure in individuals living at high altitudes as a result of sustained hypoxic pulmonary hypertension. Adaptations to high altitude and disease resistance vary among species, breeds, and individuals. The authors conducted a retrospective survey of right-sided cardiac hypertrophy associated with pulmonary arterial hypertrophy or arteriosclerosis in zoo mammals housed at Africam Safari (Puebla, México), which is located at 2,100 m above sea level. Seventeen animals with detailed pathology records matched the study criterion. Included were 10 maras (Dolichotis patagonum), 2 cotton-top tamarins (Saguinus oedipus oedipus), 2 capybaras (Hydrochaeris hydrochaeris), and 1 case each of Bennet's wallaby (Macropus rufogriseus), nilgai antelope (Boselaphus tragocamelus), and scimitar-horned oryx (Oryx dammah). All had right-sided cardiac hypertrophy and a variety of arterial lesions restricted to the pulmonary circulation and causing arterial thickening with narrowing of the arterial lumen. Arterial lesions most often consisted of medial hypertrophy or hyperplasia of small and medium-sized pulmonary arteries. All maras also had single or multiple elevated plaques in the pulmonary arterial trunk consisting of fibrosis, accompanied by chondroid metaplasia in some cases. Both antelopes were juvenile and died with right-sided congestive heart failure associated with severe pulmonary arterial lesions. To the authors' knowledge, this is the first description of cardiac and pulmonary arterial disease in zoo mammals housed at high altitudes.

A quantitative trait locus for ascites on chromosome 9 in broiler chicken lines.

A genome-wide SNP survey was used to identify chromosomal regions that showed linkage disequilibrium with respect to ascites susceptibility and ventricular hypertrophy in an F2 cross between previously described ascites-resistant and -susceptible lines. Variable number tandem repeats were used to obtain genotype data to further characterize these regions. A region on chromosome 9 (12 to 13 Mbp in 2011 assembly) shows association with ascites in the ascites lines and in several commercial broiler breeder lines with a significant sex effect. There are 2 candidate genes, AGTR1 (an angiotensin II type 1 receptor) and UTS2D (urotensin 2 domain containing), in this region that have been associated with hypertension and hypoxic response in mammals.

Cardiac hypertrophy and structural and metabolic remodeling related to seasonal dormancy in the first annual cycle in tegu lizards.

Morpho-functional adjustments in the heart of juvenile tegu lizards (Tupinambis merianae) were analyzed at distinct seasonal periods to investigate how the demands of growth and of energy saving are reconciled during the first annual cycle. The relative ventricular mass (Mv) was 31% and 69% larger in late autumn and winter dormancy, respectively, compared to early autumn. This effect did not persist during unfed arousal, suggesting that protein accumulates in the heart during hypometabolism and is degraded on arousal. Both the hypertrophy and the atrophy were disproportionate in the largest individuals. In contrast, Mv was smaller in lizards that were starved during spring activity compared to fed lizards, this effect being larger in smaller individuals. In late autumn and winter dormancy the spongy myocardium had 8% of the section area covered by lacunary spaces, which expanded after food intake during arousal and reached 29% in spring activity together with higher density of cardiomyocytes. Total and soluble proteins per mass unity were unchanged, and maximum activities of selected enzymes suggest sustained glycolytic and aerobic capacities during hypometabolism. Results indicate that important structural adjustments occur in the heart in anticipation of dormancy, and that the protein balance in the tissue is maintained at winter temperatures ~17°C.

Epidemiological, clinical, radiographic, echocardiographic findings and outcome in client-owned guinea pigs (Cavia porcellus) with cardiac disease: 80 cases (2010-2021).

OBJECTIVE: To characterize epidemiological, clinical, radiographic, and echocardiographic features of cardiac diseases in guinea pigs examined at a referral exotics center. ANIMALS: 80 guinea pigs. PROCEDURES: Medical records of guinea pigs that had echocardiography performed between June 2010 and January 2021 were reviewed. RESULTS: The percentage of guinea pig patients with cardiovascular disease was 2.8%. Clinical signs included dyspnea (46/80), lethargy (18/80), and anorexia (10/80). The most common physical examination finding was heart murmur (10/80). Radiographic abnormalities included subjective cardiomegaly (37/67), pleural effusion (21/67), and increased lung opacity (40/67). Median (range) vertebral heart score on right lateral (48/67) and ventrodorsal (39/67) projections was 9.0 vertebrae (6.6 to 13.2 vertebrae) and 10.8 vertebrae (7.9 to 13.2 vertebrae), respectively. The most common echocardiographic diagnosis was cardiomyopathy (30/80), categorized as restrictive (11/30), hypertrophic (10/30), or dilated (9/10). Other cardiac diseases included cor pulmonale (21/80), pericardial effusion (18/80), congenital heart disease (6/80), acquired valvular disease (3/80), and cardiovascular mass (2/80). Congestive heart failure was present in 36 of 80. Median survival time from diagnosis was 2.5 months (95% CI, 1.1 to 6.2 months). Animals that died from heart disease had a significantly shorter survival time than those that died from a noncardiac disease (P = .02). CLINICAL RELEVANCE: On radiographs, cardiomegaly, pleural effusion, and alveolar or interstitial lung pattern should be considered as indications for echocardiography in guinea pigs. Cardiomyopathy (restrictive, hypertrophic, or dilated), cor pulmonale, and pericardial effusion were the most common echocardiographic diagnoses. Further studies on diagnosis and treatment of cardiovascular diseases in guinea pigs are needed.

Prognostic relevance of left cardiac enlargement in dogs with preclinical myxomatous mitral valve disease.

INTRODUCTION: According to the most recent consensus guidelines on canine myxomatous mitral valve disease (MMVD), dogs with only left atrial enlargement (LAE) or left ventricular enlargement are classified as stage B1. The concomitant presence of LAE and left ventricular enlargement is needed to be classified as stage B2. The primary aim of the study was to evaluate the prognosis in stage B1 and stage B2 according to the revised definition. The secondary aim was to assess the prognostic relevance of LAE in stage B1. ANIMALS: A total of 440 dogs with MMVD, 276 in stage B1 and 164 in stage B2. MATERIALS AND METHODS: Retrospective and observational study. The left atrium-to-aorta ratio and the left ventricular end-diastolic diameter normalized were used to define cardiac dimensions. The long-term outcome was assessed by telephone interviews with owners and referring vets. Both cardiac-related and all-cause mortality were evaluated. RESULTS: Stage B1 dogs had a longer median survival time than stage B2, considering both cardiac-related death (2344 vs. 1341 days; P<0.001) and all-cause mortality (1832 vs. 855 days; P<0.001). Age, left atrium-to-aorta ratio, and the left ventricular end-diastolic diameter normalized were independent predictors of cardiac-related death and all-cause mortality. Among stage B1, dogs with LAE lived shorter than those without LAE (1183 vs. 1882 days; P=0.005) considering all-cause mortality. DISCUSSION AND CONCLUSIONS: Stage B1 dogs lived longer than stage B2 dogs. Among stage B1, LAE had prognostic relevance considering all-cause mortality. This finding could add useful prognostic information in the management of preclinical MMVD.