ACVIM consensus statement guidelines for the diagnosis, classification, treatment, and monitoring of pulmonary hypertension in dogs

Sildenafil-induced priapism in a dog : an unusual case report

BACKGROUND

Priapism is defined as erection that lasts for more than 4 h without sexual stimulation. There are various causes of priapism, but there are no reports of sildenafil-induced priapism in dogs. In human medicine, there were no pre-marketing reports of priapism caused by sildenafil, but post-marketing surveillance has shown that it is rare. In cases of pulmonary hypertension in dogs, sildenafil is the first-line drug of choice for symptomatic relief.

CASE PRESENTATION

An 11-year-old neutered male Maltese dog that presented with tachypnea and cough was diagnosed with myxomatous mitral valve disease, American College of Veterinary Internal Medicine (ACVIM) stage C, and was treated medically. Eighteen months after the diagnosis, severe pulmonary hypertension occurred due to left heart disease. At 20 months postdiagnosis, pleural effusion occurred, and sildenafil (2 mg/kg twice daily) was added to the existing treatment. Two weeks later, the dyspnea recurred, confirming pleural fluid recurrence, and sildenafil was increased to 2 mg/kg thrice daily. One day later, the patient developed persistent erections and penile pain. Penile amputation and urethrostomy were recommended but were refused; therefore, analgesia and palliative care were provided. The patient died of acute dyspnea 22 months after the first presentation, with no specific priapism recurrence at the time of death.

CONCLUSION

To the best of our knowledge, this is the first report of sildenafil-induced priapism in a dog with pulmonary hypertension.

Effects of chemotherapy treatment with doxorubicin on right ventricular function in dogs

Left ventricular dysfunction in dogs after the administration of doxorubicin (DOX) has been extensively examined. However, the effects of DOX on right ventricular (RV) function remain unknown. Therefore, the present study investigated whether the chemotherapy treatment with DOX decreases RV function. Twelve dogs (five with multicentric lymphoma, four with hemangiosarcoma, two with thyroid cancer, and one with lung adenocarcinoma) that received at least two doses of DOX were prospectively enrolled. Echocardiography and the measurement of troponin I were performed prior to each administration of DOX and approximately one month after the last administration. Right ventricular function was assessed by the RV fractional area change and RV Tei index. Two (n=4), three (n=3), four (n=3), and five (n=2) doses of DOX were administered. While no significant differences were observed in the RV fractional area change, the RV Tei index was significantly impaired after two doses of DOX. Troponin I level significantly increased after four doses. Cumulative doses of DOX correlated with the RV Tei index (r=0.77, P<0.001). The present results demonstrated that the chemotherapy treatment with DOX decreased RV function in a dose-dependent manner in dogs.

A Retrospective Study of Sildenafil Administration in 55 Cats with Cardiopulmonary Disease (2009-2021)

Sildenafil is a drug used to successfully manage a variety of cardiopulmonary disorders in people and dogs, but there is limited information on its use in cats. The objective was to review the medical records of cats that received sildenafil as part of their clinical management. Medical records and pharmacy databases were searched for cats that received sildenafil for ≥24 h between 2009 and 2021, and data were collected from medical records. Fifty-five cats received sildenafil for ≥24 h and were included in the study: 43 with primary cardiac disease (acquired, n = 28; congenital, n = 15) and 12 with primary respiratory disease. Side effects possibly attributed to sildenafil were identified in two cats (systemic hypotension, n = 1; polydipsia, n = 1), and sildenafil was discontinued in the cat with hypotension. Sildenafil was discontinued in an additional three cats due to a lack of improvement in clinical signs. No cat was documented to develop worsening pulmonary edema within 72 h of starting sildenafil. Median duration of sildenafil administration was 87 days (range, 2-2362 days). Sildenafil administration in cats appeared to be generally well-tolerated. Studies are needed to determine whether sildenafil administration to cats with cardiopulmonary disease improves the quality of life or survival times.

Platelet hyperresponsiveness and increased platelet-neutrophil aggregates in dogs with myxomatous mitral valve disease and pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) in dogs with myxomatous mitral valve disease (MMVD) is caused by increased pulmonary venous pressure. Thrombosis, vascular remodeling, and vasoconstriction mediated by platelets could exacerbate PH.

HYPOTHESIS

Dogs with PH will exhibit a hypercoagulable state, characterized by increased platelet activation, platelet-leukocyte, and platelet-neutrophil aggregate formation.

ANIMALS

Eleven dogs (≥3.5 kg) diagnosed with MMVD and PH and 10 dogs with MMVD lacking PH.

METHODS

Prospective cohort ex vivo study. All dogs underwent echocardiographic examination, CBC, 3-view thoracic radiographs, and heartworm antigen testing. Severity of PH and MMVD were assessed by echocardiography. Viscoelastic monitoring of coagulation was assessed using thromboelastography (TEG). Platelet activation and platelet-leukocyte/platelet-neutrophil interactions were assessed using flow cytometry. Plasma serotonin concentrations were measured by ELISA.

RESULTS

Unstimulated platelets from dogs with MMVD and PH expressed more surface P-selectin than MMVD controls (P = .03). Platelets from dogs with MMVD and PH had persistent activation in response to agonists. The number of platelet-leukocyte aggregates was higher in dogs with MMVD and PH compared with MMVD controls (P = .01). Ex vivo stimulation of whole blood resulted in higher numbers of platelet-neutrophil aggregates in dogs with MMVD and PH (P = .01). Assessment of hypercoagulability based on TEG or plasma serotonin concentrations did not differ between groups.

CONCLUSION AND CLINICAL IMPORTANCE

Platelet hyperresponsiveness and increased platelet-neutrophil interaction occur in dogs with MMVD and PH, suggesting that platelets play a role of in the pathogenesis of PH. Clinical benefits of antiplatelet drugs in dogs with MMVD and PH require further investigation.

The echocardiographic pulmonary to left atrial ratio: A noninvasive variable for the hemodynamic classification of pulmonary hypertension in dogs

BACKGROUND

Hemodynamic classification of pulmonary hypertension (PH) has important clinical implications. However, only a few echocardiographic variables have been used to hemodynamically classify PH in dogs.

OBJECTIVE

To evaluate the echocardiographic pulmonary to left atrial ratio index (ePLAR) in dogs with PH.

ANIMALS

Forty-six dogs with intermediate to high probability of PH.

METHODS

Cross-sectional study. Variables were compared between dogs with precapillary PH [PrePH (n = 24)] vs postcapillary PH [PostPH (n = 22)], and with combined PH [CombPH (n = 14)] vs isolated PH [IsoPH (n = 8)] using the t-, Mann-Whitney, Pearson's Chi, or Fisher's exact test. The receiver operating characteristic curve and Youden index were used to identify the optimal ePLAR cutoff value to differentiate among the groups, intraclass correlation coefficients (ICC) were used to determine the reliability of measurements.

RESULTS

The mean (SD) ePLAR of the PrePH was higher than that of the PostPH group [0.36 (0.13) vs 0.26 (0.09), respectively; P = .005]. The median (interquartile range) ePLAR of the CombPH was higher than that of the IsoPH subgroup [0.29 (0.24-0.38), vs 0.20 (0.16-0.23), respectively; P = .001]. The best cutoff value of ePLAR for identifying IsoPH was <0.245 [AUC at cutoff point = 0.86; sensitivity (95% confidence interval [CI]) = 0.71 (0.47-0.95); specificity (95% CI) = 1 (0.76-1)]. The ICC analysis indicated a high degree of reliability.

CONCLUSIONS AND CLINICAL IMPORTANCE

ePLAR can be considered a valid noninvasive variable to hemodynamically classify PH in dogs with an intermediate to high probability of PH. Assessment of ePLAR can be useful in the therapeutic management of PH in dogs.

Pulmonary thrombotic pulmonary hypertension managed using antithrombotic and pulmonary vasodilator treatment

An 8-year-old Leonberger receiving immunosuppressive treatment with clinical signs of acute dyspnea, cyanosis, and difficulty standing was referred to our institution (Day 1). Treatment including oxygen, clopidogrel, and low-molecular-weight heparin was initiated for suspected pulmonary thrombosis. However, exertional dyspnea persisted until Day 10, and increased tricuspid regurgitation velocity, pulmonary vascular resistance, and McConnell's signs also were observed. Thus, beraprost sodium was administered PO on Day 11 to treat suspected pulmonary hypertension. On Day 13, contrast-enhanced computed tomography identified extensive contrast defects in the pulmonary arteries, and IV monteplase was administered on Days 14 and 18, with marked improvement in respiratory status and exertional dyspnea on Day 20. Right ventricular function and McConnell signs also improved, and tricuspid regurgitation velocity and pulmonary vascular resistance decreased. On Day 250, echocardiography indicated further improvement in pulmonary hypertension pathophysiology. The patient was still progressing well with antithrombotic and pulmonary vasodilator treatment 400 days later.

Mycoplasma spp. pneumonia and subsequent pulmonary hypertension in a domestic ferret (Mustela putorius furo)

Treatment of Mycoplasma spp. pneumonia has rarely been described in domestic ferrets (Mustela putorius furo). A 10-month-old, 0.53 kg, female spayed domestic ferret was presented for oxygen-dependent, chronic dyspnea of one-month's duration. Physical examination findings included dyspnea, tachypnea, increased bronchovesicular sounds bilaterally, and an intermittent non-productive cough. Bloodwork abnormalities included a mild leukocytosis (8.6×103/µL), mild neutrophilia (4.0×103/µL), mild hypoalbuminemia (2.7 g/dL), mild hyperglobulinemia (3.3 g/dL), mild hyponatremia (147 mEq/L), and mild hypochloremia (111.4 mEq/L). Radiographs revealed a marked diffuse bronchial pattern with peribronchial cuffing, a mild main pulmonary artery bulge, distended caudal lobar pulmonary arteries, and decreased serosal detail within the abdomen. An echocardiogram revealed indications of moderate pulmonary hypertension and systolic anterior motion of the mitral valve. Polymerase chain reaction testing for Mycoplasma spp. was positive, and treatment was initiated with doxycycline (10 mg/kg PO q 12 h for 16 weeks), prednisolone (0.4 mg/kg PO q 12 h for 13 weeks, tapered to 0.2 mg/kg PO q 12 h for two weeks, then eventually increased to 0.7 mg/kg PO q 12 h until further notice), sildenafil (0.3 mg/kg PO q 24 h for 13 weeks), and oxygen supplementation via an oxygen cage for six weeks. On repeat echocardiogram eleven weeks after initiation of doxycycline therapy, the pulmonary hypertension had resolved. At follow up six months later, the ferret was stable on previously prescribed medications and did not require oxygen supplementation. Mycoplasma spp. and pulmonary hypertension should be considered in cases of respiratory distress in ferrets.

Radiographic and echocardiographic evaluation in rescued Korean raccoon dogs (Nyctereutes procyonoides koreensis)

Introduction

Nyctereutes procyonoides koreensis (Korean raccoon dog), a member of the Canidae family, is anatomically similar to dogs. Previous studies have used vertebral heart scale measurements to measure the cardiac size of Korean raccoon dogs on thoracic radiographs; however, the use of additional cardiac size indices, such as vertebral left arial score, intercostal space, cardiothoracic ratio, and echocardiographic indices, has not been reported. Therefore, this study aimed to establish normal reference ranges for various thoracic radiographic and echocardiographic indices in normal Korean raccoon dogs.

Methods

Twenty-six Korean raccoon dogs (11 males and 15 females) were included in this study. The thoracic radiographic indices, vertebral heart scale score, and vertebral left atrial score were measured in the right lateral view. The intercostal space and cardiothoracic ratio were measured in the ventrodorsal view. The echocardiograms were evaluated in the right parasternal long and short axis view and left parasternal apical view.

Results

The mean values for the thoracic radiographic and echocardiographic indices were as follows: vertebral heart scale, 9.12 ± 0.74; vertebral left atrial score, 1.5 ± 0.31; intercostal spaces, 3.17 ± 0.34; cardiothoracic ratio, 0.69 ± 0.07; left atrial to aortic root ratio, 1.22 ± 0.14; main pulmonary artery to aorta ratio, 1.22 ± 0.14; left ventricular end-diastolic internal diameter normalized for body weight, 1.36 ± 0.19; end-diastolic volume index, 51.07 ± 19.6; end-systolic volume index, 16.54 ± 7.45; the peak velocity of early diastolic transmitral flow, 73.13 ± 15.46 cm/s; and the ratio between the transmitral flow velocities and the peak early diastolic velocity, 1.77 ± 0.47. Only percent increase in the left ventricular end-systolic internal diameter was negatively correlated with body weight. The remaining indices showed no correlations with body weight.

Conclusion

To the best of our knowledge, this is the first case report covering both thoracic radiographic and endocardiographic indices for Korean raccoon dogs. Thus, the thoracic radiographic and echocardiographic indices established in this study may be used to evaluate the cardiac condition of Korean raccoon dogs.

Association between Thoracic Radiographic Changes and Indicators of Pulmonary Hypertension in Dogs with Heartworm Disease

Pulmonary hypertension (PH) is a consequence of pulmonary endarteritis during infection with Dirofilaria immitis in dogs. Echocardiography is the technique of choice but is not always accessible to all clinicians. This study aimed to evaluate the association of the radiological findings in dogs with heartworm disease and the presence or absence of echocardiographically characterised PH. The study included 62 heartworm-infected dogs that underwent thoracic radiographs and echocardiography. The studied dogs showed moderate to severe PH when the Right Pulmonary Artery Distensibility (RPAD) Index was <29.5%. The RPAD Index was used for comparison with thoracic radiographs. The Vertebral Heart Size (VHS), right cranial pulmonary artery passing through the fourth rib in the laterolateral projection (CrPA/R4) ratio, and right caudal pulmonary artery to the ninth rib in the dorsoventral projection (CdPA/R9) ratio showed significant differences between dogs with/without PH (p < 0.001). Sensitivity (sen) and specificity (sp) cut-off values were obtained: VHS ≥ 9.53 (sen 93.75%, sp 63.33%); CrPA/R4 ≥ 1.08 (sen 87.5%, sp 70%); and CdPA/R9 ≥ 1.10 (sen 96.88%, sp 76.66%). The CrPA/R4 and CdPA/R9 ratios showed potential as a preliminary screening tool for PH in heartworm-infected dogs, suggesting that they may reliably indicate the presence of PH and guide the decision for further diagnostic testing.

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.

Retrospective evaluation of a right heart parameter score in the assessment of precapillary pulmonary hypertension in dogs (2017-2021): 135 cases

OBJECTIVE

To determine if emergency and critical care residents can identify moderate to severe precapillary pulmonary hypertension on cardiologist-obtained cineloops using a pulmonary hypertension score (PHS) and report the interobserver variability of the PHS.

DESIGN

Multicenter, retrospective, case-control study from 2017 to 2021.

SETTING

Private referral center and veterinary teaching hospital.

ANIMALS

One hundred and thirty-five client-owned dogs that underwent diagnostic echocardiography.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records of dogs with stage B1 myxomatous mitral valve disease (MMVD) and dogs diagnosed with precapillary pulmonary hypertension (PCPH) via echocardiograms were reviewed. Dogs were categorized by a cardiologist into 5 groups (normal, B1 MMVD, mild, moderate, and severe PCPH) based on Doppler pulmonary pressure gradients and right heart morphology. Cineloops from each case were subjectively evaluated by emergency and critical care residents for the presence of right atrial and ventricular enlargement, right ventricular hypertrophy, interventricular septal flattening, and pulmonary artery and trunk enlargement to form a composite pulmonary hypertension score out of 8 (PHS8). When available, signs of peritoneal effusion and distention of the caudal vena cava were subjectively assessed to generate a pulmonary hypertension score out of 10 (PHS10). There was excellent discrimination of moderate to severe PCPH versus grouped absent to mild PCPH using PHS8 (area under the receiver operator curve [AUC] [95% confidence interval, CI] = 0.90 [0.84-0.95], P < 0.0001) and PHS10 (AUC [95% CI] = 0.89 [0.81-0.97], P < 0.0001). PHS8 ≥3 was 64% sensitive and 98% specific for moderate to severe PCPH (positive likelihood ratio [LR+] 32, negative likelihood ration [LR-] 0.37). PHS10 ≥ 3.3 was 64% sensitive and 92% specific for moderate to severe PCPH (LR+ 8, LR- 0.39). Interobserver agreement was good to excellent (intraclass correlation coefficient [ICC] = 0.74 [95% CI: 0.66-0.80], n = 135).

CONCLUSIONS

Residents identified moderate to severe PCPH in dogs using PHS on cineloops previously obtained by a cardiologist. The interrater agreement was good to excellent with limited training. Prospective studies to determine if residents can obtain diagnostic images for PHS are warranted.

Retrospective analysis of dogs and cats with a mixed form of pulmonary hypertension and suspected pulmonary capillary hemangiomatosis in comparison to animals with predomination of precapillary pulmonary hypertension

Background

Pulmonary capillary hemangiomatosis (PCH) is an idiopathic disease with the anomalous proliferation of a small capillary-like vessel in the pulmonary tissue, which can lead to a severe form of PH. There are only several cases of PCH described in veterinary literature: 27 cases in dogs and 2 cases in cats. In veterinary medicine, PH is mostly recognized as a consequence of left heart failure as a progression of the postcapillary PH to the precapillary form. PCH is mostly described as a primary disease, but resistant postcapillary PH with the high possibility of pulmonary edema raises speculation that PCH could be a secondary malformation to the left heart disease.

Aim

Discover the features associated with the shift between left- and right-sided heart disease in the context of PH development.

Methods

Retrospective analysis of materials from cats and dogs with histological markers of PCH (sPCH) versus those with right heart failure (RHF).

Results

Animals with histological and immunohistochemistry markers of PCH had a previous history of disease with left heart volume overload. There were no differences between the groups in radiography and gross pathology. Histologically, pulmonary fibrosis and arteriopathy could be found in RHF; in sPCH-a duplication of capillaries in alveolar septa and bizarre proliferation in surrounding structures.

Conclusion

PCH could be a secondary pattern of vascular remodeling due to volume overload.

Association between echocardiographic indexes and urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) in dogs with myxomatous mitral valve disease

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of tubular damage, and its elevation has been described in human and canine cardiorenal syndrome. The aim was to evaluate the association between echocardiographic indexes and urine NGAL (uNGAL) and uNGAL normalized to urine creatinine (uNGALC) in dogs with MMVD. This is a multicentric prospective cross-sectional study. A total of 77 dogs with MMVD at different ACVIM stages were included. All dogs underwent echocardiography, serum chemistry, and urinalysis. Echocardiographic data analyzed were shortening fraction (SF), left ventricular diastolic (LVIDDn) and systolic (LVIDSn) diameters normalized for body weight, left atrium to aortic root ratio (LA/Ao), maximal (LAVMax) and minimal (LAVMin) left atrial volumes, LA stroke volume (LASV), early diastolic mitral peak velocity (EVmax), EVmax to tissue Doppler E' wave (E/E'), aortic (VTIAo) and mitralic (VTIMit) velocity time integrals and their ratio (VTIMit/VTIAo), and tricuspid regurgitation velocity (TRVmax). In the univariate analysis LASV, TRVmax, LAVMax, LVIDDn, and VTIMit/VTIAo were independent predictors of increased uNGAL and uNGALC; however, only LASV [(OR: 1.96, 95% CI: 1.16 to 3.31) P = 0.01 for NGAL, and (OR: 2.79, 95% CI: 1.50 to 5.17) P < 0.001 for NGALC] and TRVmax [(OR: 1.73, 95% CI: 1.20-2.51) P = 0.002 for NGAL, and (OR: 1.50, 95% CI: 10.07-2.10) P = 0.015 for NGALC] remained statistically significant in the multivariable analysis. Based on our results, LASV and TRVmax are associated with increased uNGAL and uNGALC. These parameters might detect dogs with MMVD at higher risk of developing kidney damage.

Phosphoproteomics analysis of serum from dogs affected with pulmonary hypertension secondary to degenerative mitral valve disease

Pulmonary hypertension (PH), a common complication in dogs affected by degenerative mitral valve disease (DMVD), is a progressive disorder characterized by increased pulmonary arterial pressure (PAP) and pulmonary vascular remodeling. Phosphorylation of proteins, impacting vascular function and cell proliferation, might play a role in the development and progression of PH. Unlike gene or protein studies, phosphoproteomic focuses on active proteins that function as end-target proteins within signaling cascades. Studying phosphorylated proteins can reveal active contributors to PH development. Early diagnosis of PH is crucial for effective management and improved clinical outcomes. This study aimed to identify potential serum biomarkers for diagnosing PH in dogs affected with DMVD using a phosphoproteomic approach. Serum samples were collected from healthy control dogs (n = 28), dogs with DMVD (n = 24), and dogs with DMVD and PH (n = 29). Phosphoproteins were enriched from the serum samples and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Data analysis was performed to identify uniquely expressed phosphoproteins in each group and differentially expressed phosphoproteins among groups. Phosphoproteomic analysis revealed nine uniquely expressed phosphoproteins in the serum of dogs in the DMVD+PH group and 15 differentially upregulated phosphoproteins in the DMVD+PH group compared to the DMVD group. The phosphoproteins previously implicated in PH and associated with pulmonary arterial remodeling, including small nuclear ribonucleoprotein G (SNRPG), alpha-2-macroglobulin (A2M), zinc finger and BTB domain containing 42 (ZBTB42), hemopexin (HPX), serotransferrin (TRF) and complement C3 (C3), were focused on. Their unique expression and differential upregulation in the serum of DMVD dogs with PH suggest their potential as biomarkers for PH diagnosis. In conclusion, this phosphoproteomic study identified uniquely expressed and differentially upregulated phosphoproteins in the serum of DMVD dogs with PH. Further studies are warranted to validate the diagnostic utility of these phosphoproteins.

Comparative Study of Cardiovascular Effects of Selected Pulmonary Vasodilators in Canine Models of Mitral Valve Disease

Previous reports have shown that various oral pulmonary vasodilators are effective against canine pulmonary hypertension (PH). However, no studies have compared their hemodynamic effects. We aimed to compare the hemodynamic effects of 15 µg/kg beraprost sodium, 1.0 mg/kg sildenafil, and their combination, in dogs with experimentally induced mitral regurgitation. This experimental crossover study evaluated the hemodynamic and functional effects of oral pulmonary vasodilators by application of right-sided heart catheterization and echocardiography. Beraprost significantly decreased pulmonary and systemic vascular resistance. Additionally, beraprost increased right-ventricular stroke volume and left-ventricular cardiac output without worsening left-heart size and left-atrial pressure. The pulmonary vasodilatory effects of sildenafil were stronger, and its systemic vasodilatory effects were weaker than those of beraprost. However, sildenafil significantly increased the left-ventricular volume, left-atrial pressure indicator, and right-ventricular cardiac output. Combination therapy resulted in the strongest pulmonary and systemic vasodilating effects without worsening the left-heart size and left-atrial pressure indicators. Both beraprost and sildenafil were effective against canine PH; however, sildenafil was associated with the risk of worsening left-heart loading. Combination therapy with beraprost and sildenafil synergistically dilated pulmonary and systemic vessels, indicating a more potent treatment option for severe PH cases.

The utility of cardiac-gated computed tomography in diagnosing a reverse patent ductus arteriosus in a dog with a concurrent intracardiac right-to-left shunt

A five-month-old male intact Goldendoodle presented for evaluation for peripheral cyanosis following exercise. Transthoracic echocardiography demonstrated severe right ventricular wall thickening and right atrial dilation secondary to pulmonary hypertension. An agitated saline contrast study demonstrated an interatrial right-to-left shunt. Cardiac-gated computed tomography confirmed a reverse patent ductus arteriosus. This case report highlights the utility of cardiac-gated computed tomography in identifying multi-level intra- and extra-cardiac shunts.

Control line failure in Angiostrongylus vasorum point-of-care serology test in dogs with angiostrongylosis due to suspected hook effect

OBJECTIVES

Angiostrongylosis is a significant differential for a diverse range of clinical signs in dogs, many of whom present acutely and sometimes with fatal consequences. Point-of-care diagnostic assays include a commercially available Angiostrongylus vasorum qualitative direct lateral flow assay.

MATERIALS AND METHODS

Case records from one referral centre from dogs with an invalid A. vasorum lateral flow assay, comprising an absent control line alongside a visible test line, were reviewed. As control line failure was hypothesised to be due to antigen excess; where available the A. vasorum lateral flow assay was repeated using dilutions of the original serum.

RESULTS

Six dogs had an invalid A. vasorum lateral flow assay result. Five dogs had presented with acute-onset, severe clinical disease consistent with angiostrongylosis, and one dog was a clinically healthy in-contact. Clinical suspicion of angiostrongylosis was confirmed using alternative diagnostic testing and/or response to treatment. Repetition of the A. vasorum lateral flow assay, in four cases, using diluted plasma (10% to 12.5% v/v) resulted in the appearance of a control line alongside the visible test line.

CLINICAL SIGNIFICANCE

A heavy burden of A. vasorum infection resulting in angiostrongylosis should be suspected in dogs with compatible clinical signs and an invalid A. vasorum lateral flow assay result due to control failure alongside a visible test line. Repetition of the test with a diluted serum may be considered to account for the hook effect, also known as the postzone phenomenon, as a possible cause.

Volumetric quantification identifies some left atrial dilations undetected by left atrium:aorta ratio measurements: A prospective echocardiographic study in 155 Cavalier King Charles Spaniels with and without degenerative mitral valve disease

INTRODUCTION

Degenerative mitral valve disease (DMVD) is the most common canine heart disease with a high predisposition in Cavalier King Charles Spaniels (CKCSs). Mitral regurgitation related to DMVD can lead to left atrial (LA) dilation, which is associated with survival time. Left-atrial-to-aortic (LA:Ao) ratio assessed by two-dimensional echocardiography is commonly used to evaluate LA size. The objectives of this prospective observational study were therefore 1) to compare different echocardiographic methods (i.e., monoplane and biplane Simpson's methods of discs (SMOD) and area-length methods (ALM)) in evaluating LA volume (LAvol) in CKCSs, 2) to assess LA volumes according to DMVD severity and, 3) compare the ability of LAvol and LA:Ao ratio to identify LA enlargement in CKCSs with subclinical DMVD (i.e., American College of Veterinary Internal Medicine (ACVIM) stage B).

MATERIALS AND METHODS

155 CKCSs, either healthy or affected by DMVD, were recruited. Variability and concordance between volumetric methods were evaluated. Values were analyzed according to 2019 ACVIM stages.

RESULTS

All Lin's concordance correlation coefficients regarding intra- and inter-observer variability were considered as very good to excellent. Monoplane methods and ALM produced higher values of LAvol than biplane methods and SMOD, respectively. The upper limit of normal end-systolic LAvol/body weight (LASvol/BW) was defined as 0.90 mL/kg. Left atrial volumes significantly increased with ACVIM stages. Additionally, 37% of stage B1 CKCSs demonstrated LA enlargement using LASvol/BW assessment, with significantly lower LASvol/BW values in dogs with regurgitation fraction ≤30% than in others (p<0.01).

CONCLUSION

In CKCSs, LAvol methods are not interchangeable. In ACVIM stage B CKCSs, LAvol quantification is more effective to detect LA enlargement than LA linear measurements.

Proteomic analysis of the serum in dogs with pulmonary hypertension secondary to myxomatous mitral valve disease: the preliminary study

Background

Pulmonary hypertension (PH) is a common complication in dogs with myxomatous mitral valve disease (MMVD), characterized by elevated blood pressure in pulmonary artery. Echocardiography is a reliable technique for PH diagnosis in veterinary medicine. However, it is limited to use as an early detection method. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has found extensive application in the discovery of serum protein biomarkers for various diseases. The objective of this study was to identify serum proteins in healthy control dogs and MMVD dogs both with and without PH using LC-MS/MS.

Materials and methods

In this research, a total of 81 small-breed dogs participated, and they were categorized into three groups: the control (n = 28), MMVD (n = 24) and MMVD+PH (n = 29) groups. Serum samples were collected and analyzed by LC-MS/MS.

Results

Differentially expressed proteins were identified, and the upregulated and downregulated proteins in MMVD+PH group including Myomesin 1 (MYOM1) and Histone deacetylase 7 (HDAC7), Pleckstrin homology domain containing M3 (PLEKHM3), Diacylglycerol lipase alpha (DAGLA) and Tubulin tyrosine ligase like 6 (TTLL6) were selected as proteins of interest in MMVD dogs with PH.

Conclusion

Different types of proteins have been identified in healthy dogs and MMVD dogs with and without PH. Additional studies are needed to investigate the potential of these proteins as biomarkers for PH in dogs with MMVD.

Severe Pulmonary Hypertension and Pulmonary Thrombi in a Dog

•PAs can protrude from the lung with severe obstruction and dilation. •Dogs can develop PT secondary to protein-losing nephropathy. •Evidence of classic histopathologic changes associated with chronic PH was present. •Dogs can live with chronic severe PA obstruction and severe PH secondary to PT.

Effects of acute atrial fibrillation and cardioversion on left and right atrial pressures in a dog

The occurrence of right-sided congestive heart failure (CHF) in dogs with left-sided heart disease is well-recognized, but its mechanisms are incompletely understood. A 12-year-old Maltese dog was admitted to the clinic for left atrial decompression to treat recurrent CHF due to severe myxomatous mitral valve disease (MMVD). Left atrial decompression was successful but atrial fibrillation (AF) occurred during the procedure. Electric cardioversion restored normal sinus rhythm (NSR) and the dog's recovery was uneventful. This sequence of events made it possible to study intracameral pressures individually in each atrium in a dog with naturally occurring MMVD during AF and again during NSR. Although pressures in both atria declined following cardioversion, the right atrial pressure declined to a greater degree. These findings indicated a disproportionate effect of AF on right atrial pressure. This difference was noteworthy given the long-standing clinical observation that dogs with MMVD have a higher prevalence of right-sided CHF when AF is present. Key clinical message: A dog with MMVD had a greater reduction in right atrial pressure than in left atrial pressure when its AF was cardioverted as part of a cardiac catheterization procedure. This observation proposed a mechanism for the well-known but unexplained observation that dogs with MMVD manifest right-sided CHF disproportionately more often when they have AF.

Proteomic analysis of pulmonary arteries and lung tissues from dogs affected with pulmonary hypertension secondary to degenerative mitral valve disease

In dogs with degenerative mitral valve disease (DMVD), pulmonary hypertension (PH) is a common complication characterized by abnormally elevated pulmonary arterial pressure (PAP). Pulmonary arterial remodeling is the histopathological changes of pulmonary artery that has been recognized in PH. The underlying mechanisms that cause this arterial remodeling are poorly understood. This study aimed to perform shotgun proteomics to investigate changes in protein expression in pulmonary arteries and lung tissues of DMVD dogs with PH compared to normal control dogs and DMVD dogs without PH. Tissue samples were collected from the carcasses of 22 small-sized breed dogs and divided into three groups: control (n = 7), DMVD (n = 7) and DMVD+PH groups (n = 8). Differentially expressed proteins were identified, and top three upregulated and downregulated proteins in the pulmonary arteries of DMVD dogs with PH including SIK family kinase 3 (SIK3), Collagen type I alpha 1 chain (COL1A1), Transforming growth factor alpha (TGF-α), Apoptosis associated tyrosine kinase (AATYK), Hepatocyte growth factor activator (HGFA) and Tyrosine-protein phosphatase non-receptor type 13 (PTPN13) were chosen. Results showed that some of the identified proteins may play a role in the pathogenesis of pulmonary arterial remodeling. This study concluded shotgun proteomics has potential as a tool for exploring candidate proteins associated with the pathogenesis of PH secondary to DMVD in dogs.

Developmental lung disease in a cat associated with high probability of severe pulmonary hypertension: natural history, histopathology and genetic analysis

Case summary

This report describes the diagnostic findings, natural history and genetic analysis of the candidate gene Forkhead Box F1 (FOXF1) in a young cat with developmental lung disease and high probability of pulmonary hypertension. A 1-year-old male entire Chartreux cat was referred for cardiac murmur investigation and exercise intolerance. Echocardiography identified a high-velocity tricuspid regurgitant jet with right-sided cardiac changes, supporting a high probability of pulmonary hypertension. No congenital cardiac shunts or left-sided cardiac changes were found to support a primary cardiac cause of pulmonary hypertension. Extensive laboratory work, thoracic radiographs and CT were performed. Histopathological characterisation (lung biopsy and later post mortem) was necessary to reach the final diagnosis. Eight months after diagnosis, the cat developed right-sided congestive heart failure, eventually leading to euthanasia. Survival from diagnosis to death was 12 months.

Relevance and novel information

Developmental lung disease belongs to a group of diffuse lung diseases in humans associated with pulmonary hypertension. The veterinary literature describing lung growth disorders in cats is sparse, and the present report provides information on clinical presentation and progression alongside a thorough diagnostic workup, which may aid clinicians in identifying this condition. Lung biopsy was pivotal in reaching the final diagnosis. No causal variants in FOXF1 were identified.

Efficacy and tolerability of the American Heartworm Society therapeutic protocol in dogs affected by heartworm disease without caval syndrome

OBJECTIVES

The American Heartworm Society medical protocol represents the current standard of therapy for canine heartworm disease without caval syndrome. However, data on the tolerability of this protocol are limited. This study aimed to describe efficacy and prevalence of possible treatment-related side effects in dogs with heartworm disease treated using the American Heartworm Society protocol.

MATERIALS AND METHODS

For this retrospective multi-centre cohort study, dogs diagnosed with classes 1 to 3 heartworm disease that completed the American Heartworm Society medical protocol were searched in four medical databases. Demographic, clinical, diagnostic, therapeutic and outcome data, including the number and type of possible treatment-related side effects, were retrieved.

RESULTS

Thirty-five dogs were included. The median age and bodyweight were 6 years (1 to 13 years) and 17.3 kg (4.9 to 50 kg), respectively. Heartworm disease was classified as classes 1, 2 and 3 in 20 of 35, 11 of 35 and four of 35 dogs, respectively. In addition to the therapeutic recommendations of the American Heartworm Society, eight of 35 dogs underwent sedation to favour melarsomine administration, and 30 of 35 received ice at the injection site. After adulticide therapy, all dogs were hospitalised with cage rest [median time 12 hours (6 to 48 hours)]. All dogs survived the treatment. All dogs with long-term follow-up (32/35) became negative. Furthermore, treatment-related side effects were rare, mild and rapidly recovered without the need for supporting therapies; these included depression/lethargy (4/35 dogs), cough (2/35 dogs) and lameness, pain and gastrointestinal signs (1/35 dog each).

CLINICAL SIGNIFICANCE

The American Heartworm Society medical protocol is efficient and safe in dogs with classes 1 to 3 heartworm disease.

Right Ventricle Strain Assessed by 2-Dimensional Speckle Tracking Echocardiography (2D-STE) to Evaluate Pulmonary Hypertension in Dogs with Dirofilaria immitis

Echocardiographic assessment of the right ventricle is helpful for analysing the pathophysiology of heartworm disease and detecting pulmonary hypertension (PH) in dogs. In veterinary cardiology, the study of myocardial deformation using two-dimensional speckle tracking (2D-STE) echocardiography has become increasingly acknowledged as useful for quantifying right ventricular function. The aim of this study was to evaluate the usefulness of myocardial deformation strain of the right ventricular free wall (FWS), global deformation strain of the right ventricle, including the interventricular septum (GS), and tissue motion annular displacement of the tricuspid valve (TMAD) in a cohort of dogs with heartworm (Dirofilaria immitis) disease and to determine cut-off values for detecting the presence of PH. Out of the 93 dogs tested, 71% were diagnosed with heartworm infection. PH was identified in 41% of the infected dogs following the American College of Veterinary Internal Medicine (ACVIM) guidelines, based on the peak tricuspid regurgitation velocity to calculate the tricuspid regurgitation pressure gradient (TRPG), while other routine measurements were used, including the right pulmonary artery distensibility index (RPADi). The 2D-STE mode measurements were determined using Right Ventricular Automated Function Imaging (RV AFI®) software. The statistical analysis showed significant differences in the studied parameters among dogs with and without PH. Additionally, sensitivity (sen) and specificity (sp) cut-off values were obtained (GS ≥ -21.25%, sen 96%, sp 86.4%; FWS ≥ -21.95%, sen 92.56%, sp 95.5%; TMAD ≤ 0.85 cm, sen 70.4%, sp 83.3%). These results demonstrated that GS, FWS, and TMAD could be used as supplementary and alternative variables to conventional echocardiographic measurements when detecting PH in dogs with heartworm disease.

Left ventricular eccentricity index to assess precapillary pulmonary hypertension in dogs

INTRODUCTION

Interventricular septal flattening, frequently present in pulmonary hypertension (PH) can be quantified by the left ventricular eccentricity index (EI) measured at end-diastole (EId), end-systole (EIs) and at maximal septal flattening (EIm). In humans, EI correlates with invasive pulmonary arterial pressure. The aim of this study was to evaluate if EI correlates with parameters of right heart remodeling (RHR) and if EI is a quantitative marker of PH in dogs.

MATERIALS AND METHODS

Left ventricular eccentricity indices were retrospectively measured in four groups (no, mild, moderate and severe PH) with interpretable tricuspid and/or pulmonary regurgitation.

RESULTS

Ninety-seven dogs were included, with no (n = 29), mild (n = 13), moderate (n = 25) and severe (n = 30) PH. The intra- and inter-observer variability for EI measurements ranged from 2 % to 11 %. All EI were significantly elevated in severe compared to no, mild and moderate PH (P < 0.0005). In the moderate group, EIs and EIm were higher compared to the no PH group (P < 0.01). Tricuspid and pulmonary regurgitation pressure gradients and RHR parameters correlated with EId, EIs and EIm in all groups. Optimal cut-off values discriminating moderate and severe PH from no and mild PH were 1.24 (Sensitivity (Se) 60 %; Specificity (Sp) 90 %) for EId, 1.34 (Se 67 %; Sp 95 %) for EIs and 1.37 (Se 76 %; Sp 83 %) for EIm.

CONCLUSIONS

Left ventricular eccentricity indices are reproducible echocardiographic variables increasing with severity of PH. Dogs with moderate and severe PH can be discriminated from dogs with no or mild PH using EIs and EIm.

Case report: Application of color Doppler sonography for the assessment of pulmonary consolidations in a dog

A 1,5-year-old male Maltipoo was presented to the emergency service for dyspnea, weakness, and cough. An echocardiographic examination showed evidence of pulmonary hypertension with a McConnell sign. Lung ultrasound, including color Doppler, was performed and identified two distinct populations of lung consolidation. Color Doppler analysis of the first type of consolidation showed the absence of blood flow within regions of the consolidation and flow amputation. These findings were consistent with the "vascular sign" reported in human medicine and prompted consideration of pulmonary thromboembolism as a differential diagnosis. In the second type of consolidation, color Doppler identified blood flow within the pulmonary vessels of the consolidated lung, forming a "branching tree-like" pattern that followed the anatomical course of the pulmonary vasculature. These findings suggested that blood flow was preserved within the pulmonary vasculature of the consolidated lung and prompted consideration of inflammatory causes of pulmonary pathology. On recheck 6 days later, recanalization of the first type of consolidation was identified with color Doppler. The case was followed serially once a month for 5 months with LUS, which showed continued improvement. Based on a positive fecal Baermann test, a final diagnosis of Angiostrongylus vasorum was made. New or Unique information Provided-this is the first report of color Doppler LUS being used to characterize and help differentiate the cause of lung consolidation in dogs.

Echocardiographic reference intervals of the dimensions of the main pulmonary artery and the right pulmonary artery: a prospective study in 269 healthy dogs

INTRODUCTION

No data are available on the echocardiographic reference intervals (RIs) for the main pulmonary artery (MPA) and right pulmonary artery (RPA) dimensions in a large sample of dogs. Therefore, we aimed to describe the echocardiographic RIs of the MPA and RPA dimensions in normal dogs.

ANIMALS, MATERIALS, AND METHODS

Two hundred and sixty nine healthy dogs of different breeds, age and body weight (BW) were prospectively enrolled in this multicenter, observational study. The MPA diameter, RPA maximum diameter (RPAmax), and RPA minimum diameter (RPAmin) were measured from the right parasternal short axis view. Prediction intervals (PIs) for MPA, RPAmax and RPAmin were generated using allometric scales. Reference intervals (RI) of MPA indexed to the ascending aorta (MPA/AO), and RPAmax and RPAmin indexed to the aortic annulus (RPAmax/Aod and RPAmin/Aod), were defined.

RESULTS

A positive linear relationship between MPA, RPAmax, RPAmin and BW was evident after logarithmic transformation (R2 = 0.859, R2 = 0.787 and R2 = 0.725, respectively; P<0.0001). According to allometric scales, the PI for the MPA normalized for BW (MPA_N) was between 5.50 and 8.07, the PI for the RPAmax normalized for BW (RPAmax_N) was between 3.23 and 5.62, while the PI for the RPAmin normalized for BW (RPAmin_N) was between 1.62 and 3.30. The median MPA/AO was 0.92 (RI, 0.78-1.01), the median RPAmax/Aod was 0.70 (RI, 0.53-0.98) and the median RPAmin/Aod was 0.40 (RI, 0.29-0.61).

DISCUSSION AND CONCLUSIONS

The reported RIs of the MPA and RPA dimensions in normal dogs could increase the diagnostic accuracy of transthoracic echocardiography in the identification of pulmonary artery enlargement in dogs.

Indicators for pulmonary hypertension in dogs with degenerative mitral valve disease

Background and Aim

Pulmonary hypertension (PH) is a common complication of degenerative mitral valve disease (DMVD) in dogs. This study aimed to determine PH indicators in dogs with stage C DMVD through thoracic radiography and M-mode and 2-dimensional echocardiography.

Materials and Methods

A retrospective study of 133 dogs with DMVD stage C was conducted. The patients were divided into two groups: DMVD and DMVD with PH. Characteristics, thoracic radiographic findings, and echocardiographic variables were recorded for analysis.

Results

Pulmonary hypertension was diagnosed in 56 dogs, with a prevalence of 42.1%. Univariable logistic regression analysis revealed associations among PH and right-sided heart enlargement, pulmonary artery enlargement, left ventricular size, and percent fractional shortening. Multivariable logistic regression analysis demonstrated that pulmonary artery enlargement (odds ratio [OR]: 5.96; 95% confidence interval [CI]: 1.45-24.54; p = 0.014) and decreased left ventricular size (OR: 0.02; 95%CI: 0.003-0.13; p = 0.001) were significantly associated with PH. The accuracy of predicting PH in dogs at DMVD stage C using pulmonary artery enlargement combined with decreased left ventricular size was moderate (area under the curve [AUC] 0.77; 95%CI: 0.68-0.86).

Conclusion

Pulmonary hypertension is common in dogs with DMVD stage C. The presence of pulmonary artery enlargement assessed by radiography and decreased left ventricular size assessed by echocardiography, were associated with PH and may serve as predictors of PH in DMVD stage C.

Osteopontin and fibronectin in lung tissue, serum, and bronchoalveolar lavage fluid of dogs with idiopathic pulmonary fibrosis and control dogs

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) affects West Highland white terriers (WHWTs). Osteopontin (SPP1) and fibronectin (FN1) are associated with human IPF and are overexpressed by bronchoalveolar lavage fluid (BALF) macrophages in dogs with IPF.

OBJECTIVE

To investigate the value of these proteins as biomarkers of IPF.

ANIMALS

West Highland white terriers (WHWTs) with IPF, control WHWTs, and terriers.

METHODS

Cross-sectional observational study. Immunohistochemistry was used to localize SPP1 and FN1 in lung tissue. Serum and BALF SPP1 and FN1 concentrations were measured using canine ELISA kits and compared between groups.

RESULTS

Osteopontin stained ciliated epithelial cells, smooth muscular cells, and macrophages of all included dogs, and type-II pneumocytes and extracellular matrix of all 12 diseased WHWTs, 4/6 control WHWTs, and none of the 3 terriers. Osteopontin serum concentration was higher in diseased WHWTs (n = 22; 2.15 ng/mL [0.74-5.30]) compared with control WHWTs (n = 13; 0.63 ng/mL [0.41-1.63]; P = .005) and terriers (n = 15; 0.31 ng/mL [0.19-0.51]; P < .0001), and in control WHWTs compared with terriers (P = .005). Osteopontin BALF concentrations were higher in diseased (0.27 ng/mL [0.14-0.43]) and control WHWTs (0.25 ng/mL [0.14-0.40]), compared with terriers (0.02 ng/mL [0.01-0.08]; P < .0001 and P = .003, respectively). Fibronectin (FN1) serum concentrations were lower in diseased dogs (1.03 ng/mL [0.35-1.48]) and control WHWTs (0.61 ng/mL [0.24-0.65]) compared with terriers (2.72 ng/mL [0.15-5.21]; P < .0001 and P = .0001, respectively). There was no difference in FN1 immunostaining and FN1 BALF concentrations between groups.

CONCLUSIONS

Results suggest that SPP1 is involved in pathogenesis of IPF and could predispose that breed to the disease. Osteopontin serum concentration could serve as a diagnostic biomarker of IPF.

Bronchial collapse and bronchial stenting in 9 dogs

BACKGROUND

Principal and lobar bronchial collapse is increasingly recognized as an isolated entity.

OBJECTIVE

Retrospectively describe the procedure and outcomes of dogs undergoing bronchial stenting at a single referral hospital.

ANIMALS

Nine client-owned dogs with variable degrees of collapse of the left principal bronchus (LPB), lobar bronchus 1 (LB1), and lobar bronchus 2 (LB2), and with clinically relevant signs of respiratory dysfunction.

METHODS

Data were collected from patient records. All dogs underwent stenting of the LPB and LB2. Anatomic and functional impairment grades were assigned to each case before and 4 weeks after stenting. Data regarding response to stenting and complications were evaluated.

RESULTS

Bronchial stenting was considered successful in all cases, with all dogs experiencing improved quality of life (QOL), and decreased functional impairment grade at 4 weeks post-stenting. Follow-up of >6 months was available for 6 dogs and of these, 5 were alive at 12 months, 3 were alive at 18 months, and 1 was alive at 24 months. Stent-related complications occurred in 4 dogs, and were resolvable in 3. Two dogs developed pneumothorax, 1 developed recurrent pneumonia, and 1 developed new-onset coughing. All dogs had mild and manageable coughing post-stenting.

CONCLUSIONS AND CLINICAL IMPORTANCE

Stenting of the LBP and LB2 might be an effective option for dogs with advanced collapse of these bronchi and associated signs. Although all included dogs had resolution or improvement of clinical signs considered life-threatening or as affecting QOL, ongoing coughing is expected. Patient selection appears important with regard to achieving successful outcomes.

The Role of Point-of-Care Ultrasound in Managing Cardiac Emergencies

Point-of-care ultrasound (POCUS) is a useful imaging tool for the diagnosis and monitoring of cardiac emergencies. Unlike complete echocardiography, POCUS is a time-sensitive examination involving a subset of targeted thoracic ultrasound views to identify abnormalities of the heart, lungs, pleural space, and caudal vena cava. When integrated with other clinical information, POCUS can be helpful in the diagnosis of left-sided and right-sided congestive heart failure, pericardial effusion and tamponade, and severe pulmonary hypertension and can help clinicians monitor resolution or recurrence of these conditions.

Utility of vertebral left atrial size and vertebral heart size to aid detection of congestive heart failure in dogs with respiratory signs

BACKGROUND

Differentiating cardiogenic vs noncardiogenic causes of respiratory signs can be challenging when echocardiography is unavailable. Radiographic vertebral left atrial size (VLAS) and vertebral heart size (VHS) have been shown to predict echocardiographic left heart size, with VLAS specifically estimating left atrial size.

HYPOTHESIS/OBJECTIVES

Compare the diagnostic accuracy of VLAS and VHS to predict left-sided congestive heart failure (CHF) in dogs presenting with respiratory signs.

ANIMALS

One-hundred fourteen dogs with respiratory signs and radiographic pulmonary abnormalities.

METHODS

Retrospective cross-sectional study. Dogs had to have an echocardiogram and thoracic radiographs obtained within 24 hours. Diagnosis of CHF was confirmed based on the presence of respiratory signs, cardiac disease, LA enlargement, and cardiogenic pulmonary edema.

RESULTS

Fifty-seven dogs had CHF and 57 did not have CHF. Compared to VHS (area under the curve [AUC] 0.85; 95% confidence interval [CI], 0.77-0.91), VLAS was a significantly (P = .03) more accurate predictor of CHF (AUC, 0.92; 95% CI, 0.85-0.96). Optimal cutoff for VLAS was >2.3 vertebrae (sensitivity, 93.0%; specificity, 82.5%). Murmur grade (P = .02) and VLAS (P < .0001) were independently associated with CHF and VHS was not. Increased VHS (54%) was significantly (P = .01) more common than increased VLAS (24%) in dogs without CHF. Results were similar in a subsample of older and smaller dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

When echocardiography is unavailable, VLAS and murmur grade have clinically utility to aid in differentiating cardiogenic from noncardiogenic respiratory signs. These findings might be especially useful to help rule out CHF in dogs with increased VHS that present with respiratory signs.

Impact of a combination of pimobendan, furosemide, and enalapril on heart rate variability in naturally occurring, symptomatic, myxomatous mitral valve degeneration dogs

BACKGROUND

Pimobendan, diuretics, and an angiotensin-converting enzyme inhibitor (ACEi) are widely used for the management of chronic valvular heart disease in dogs; however, the effects of that combination on heart rate variability (HRV) are unknown. The purpose of this study was to assess the HRV of symptomatic myxomatous mitral valve degeneration (MMVD) dogs in response to therapy with a combination of pimobendan, diuretics, and ACEi.

RESULTS

MMVD stage C (n = 17) dogs were enrolled and a 1-hour Holter recording together with echocardiography, blood pressure measurement, and blood chemistry profiles were obtained before and 1, 3, and 6 months after oral treatment with pimobendan (0.25 mg/kg), enalapril (0.5 mg/kg), and furosemide (2 mg/kg) twice daily. The results revealed that MMVD stage C dogs at the baseline had lower values of time-domain indices, low frequency (LF), high frequency (HF), and total power, as well as higher value of LF/HF. Triple therapy significantly increases these parameters in MMVD stage C dogs (P < 0.05). A positive moderate correlation was observed between time domain parameters and a left ventricular internal diastole diameter normalized to body weight (P < 0.05).

CONCLUSIONS

It can be concluded that MMVD stage C dogs possess low HRV due to either the withdrawal of parasympathetic tone or enhanced sympathetic activation, and a combination therapy was shown to enhance cardiac autonomic modulation inferred from the increased heart rate variability. Therefore, a combination therapy may be useful for restoring normal autonomic nervous system activity in dogs with MMVD stage C.

Preliminary study of neurofilament light chain as a biomarker for hypoxia-induced neuronal injury in dogs

Neurofilament light chain (NfL) is a neuroaxonal protein in the nervous system. NfL has recently been demonstrated to be a biomarker for various neurological diseases. In this study, we investigated the potential role of NfL in hypoxia-induced neuronal injury in dogs. Serum NfL levels were determined using a single-molecule array. Serum NfL concentrations were significantly higher in hypoxemic dogs without neurological signs (n = 6, 175.5 pg/mL) than in healthy dogs (n = 15, 15.9 pg/mL; p < 0.0001). Therefore, neuronal injury should be considered in dogs with hypoxemia caused by cardiopulmonary diseases, even in the absence of neurological signs.

Diagnostic value of two-dimensional echocardiographic measurements of the pulmonary artery diameter and the pulmonary artery distensibility index to detect pulmonary hypertension in horses

INTRODUCTION/OBJECTIVES

Echocardiographic diagnosis of pulmonary hypertension (PH) in horses is usually based on Doppler interrogation of tricuspid (TR) or pulmonic regurgitation (PR). This study aimed at investigating two-dimensional echocardiographic (2DE) variables, including pulmonary artery diameter (PAD) and pulmonary artery distensibility index (PADI), to diagnose PH.

ANIMALS, MATERIALS AND METHODS

41 healthy horses; 82 horses with TR or PR and normal intracardiac pressure gradients; and 35 horses with TR or PR velocities indicating PH. The 2DE variables were compared between groups, cut-offs for the diagnosis of PH were determined, and conditional inference trees served to identify the variable best predicting PH in the absence of TR or PR.

RESULTS

Horses with PH had larger end-diastolic cross-sectional (short-axis) PAD (PADed-sx) (5.8 ± 1.0 cm; mean ± SD) and smaller PADI[/PADps] (15.4 ± 7.7%) than healthy horses (5.0 ± 0.6 cm, P<0.0001; 20.5 ± 4.4%, P<0.001) and horses with TR or PR but no PH (5.3 ± 0.6 cm, P=0.003; 18.8 ± 4.2%, P=0.005). PADed-sx predicted PH with sensitivity (Se) = 36% and specificity (Sp) = 94% (cut-off 6.0 cm, AUC = 0.668, P=0.002), while PADI[/PADps] predicted PH with Se = 43% and Sp = 92% (cut-off 13.7%, AUC = 0.662, P=0.004). In the absence of TR, PADed-sx and the end-diastolic long-axis aortic diameter-to-PADed-sx ratio (AoDed-lx/PADed-sx) were most suitable to diagnose PH.

CONCLUSION

Pulmonary artery crosssectional (short-axis) diameter at end-diastole measured in a right-parasternal long axis view of the left ventricular outflow tract and Pulmonary artery distensibility index were moderately specific but not very sensitive to diagnosing PH. Nonetheless, they may be used as complementary indices suggesting PH in the absence of TR or PR.

Idiopathic synchronous diaphragmatic flutter in a 2-year-old Jack Russell terrier dog

A 2-year-old neutered male Jack Russell terrier dog was presented for persistent, involuntary, bilateral contractions of the hypochondriac regions of the abdominal wall that had been present for 1.5 y. Electrocardiography and fluoroscopic evaluation revealed that the contractions were synchronous with the heartbeat, consistent with a synchronous diaphragmatic flutter. Thoracic radiographs, echocardiography, and serum electrolytes did not identify an underlying cause. This case report describes a rare presentation of idiopathic, long-lasting, synchronous diaphragmatic flutter in a dog. Key clinical message: Synchronous diaphragmatic flutter is a rare condition characterized by contractions of the diaphragm that are synchronous with the heartbeat; this condition can mimic a serious cardiac or respiratory condition.

Investigation of red blood cell and platelet indices in adult dogs suffered from myxomatous mitral valve disease with and without pulmonary hypertension

Background

Pulmonary hypertension (PH) is a common complication of cardiopulmonary disease. In dogs, PH commonly occurs secondary to myxomatous mitral valve disease (MMVD). Red blood cell and platelet indices including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), mean platelet volume (MPV) and platelet distribution width (PDW), have previously been found to be indicators for predicting and prognosing PH in humans. Therefore, this study aimed to investigate whether these indices are associated with MMVD and/or PH in dogs.

Methods

Two hundred and forty-six dogs were retrospectively recruited for the study and classified into 4 groups: normal (n = 49), MMVD (n =102), PH (n =17), MMVD+PH (n =78). A sub-analysis was performed in dogs with MMVD without evidence of PH according to stage B1 (n =20), stage B2 (n =15), stage C (n =67). The data are expressed as median (interquartile range).

Results and discussion

No significant differences (p < 0.05) were found in MCV, RDW and MPV among all groups (normal, MMVD, PH and MMVD+PH). However, decreases in MCH and MCHC were found in MMVD [22.40 (20.90-23.50) pg and 35.25 (33.08-36.90) g/dL], MMVD+PH [22.25 (20.85-23.98) pg and 35.65 (33.30-37.33) g/dL] and PH groups [21.20 (20.60-22.20) pg and 33.80 (32.75-35.70) g/dL] compared to the normal dogs [24.29 (23.55-24.90) pg and 38.20 (37.50-39.05) g/dL] (p < 0.001). Decreases in PDW were found in dogs in the MMVD+PH [15.10 (14.98-15.30) %] groups compared to dogs in the normal group [15.30 (15.10-15.50) %] (p = 0.004). Sub-analysis of MMVD dogs without PH showed a decrease in MCH in dogs with stage B2 MMVD [21.00 (20.50-22.90) pg] and stage C MMVD [22.40 (20.90-23.20) pg] compared to normal dogs [24.29 (23.55-24.90) pg] (p < 0.001). MCHC of dogs with stage B1 [36.55 (33.53-37.78) g/dL] (p = 0.004), B2 [32.90 (32.00-35.00) g/dL] (p < 0.001) and C MMVD [35.30 (33.30-36.80) g/dL] (p < 0.001) were lower than those of normal dogs [38.20 (37.50-39.05) g/dL]. PDW in the stage C MMVD group [15.10 (15.00-15.30) %] was reduced compared to the normal group [15.30 (15.10-15.50) %] (p  = 0.042) and the stage B1 MMVD group [15.35 (15.23-15.68) %] (p = 0.002). MCH, MCHC and PDW were negatively correlated with the left atrial and left ventricular size.

Conclusion

Decreases in MCH and MCHC are related to MMVD, precapillary PH and postcapillary PH while PDW are associated with MMVD severity but not with the presence of PH.

Perivascular inflammatory cells and their association with pulmonary arterial remodelling in dogs with pulmonary hypertension due to myxomatous mitral valve disease

Pulmonary hypertension (PH), an increase in pulmonary arterial pressure (PAP), may occur in dogs affected with myxomatous mitral valve disease (MMVD). Recent studies suggest that an accumulation of perivascular inflammatory cells may be involved with medial thickening which is a sign of the pulmonary artery remodelling in PH. The aim of this study was to characterise perivascular inflammatory cells in the surrounding pulmonary arteries of dogs with PH due to MMVD compared to MMVD dogs and healthy control dogs. Nineteen lung samples were collected from cadavers of small-breed dogs (control n = 5; MMVD n = 7; MMVD + PH n = 7). Toluidine blue stain and multiple IHC targeting α-SMA, vWF, CD20, CD68 and CD3 was performed to examine intimal and medial thickening, assess muscularisation of the small pulmonary arteries and characterise perivascular leucocytes. Medial thickening without intimal thickening of pulmonary arteries and muscularisation of normally non-muscularised small pulmonary arteries was observed in the MMVD and MMVD + PH groups compared with the control group. The perivascular numbers of B lymphocytes, T lymphocytes and macrophages was significantly increased in the MMVD + PH group compared with the MMVD and control groups. In contrast, the perivascular number of mast cells was significantly higher in the MMVD group compared with the MMVD + PH and control groups. This study suggested that pulmonary artery remodelling as medial thickening and muscularisation of the normally non-muscular small pulmonary arteries is accompanied by the accumulation of perivascular inflammatory cells.

Echocardiographic characteristics of dogs with pulmonary hypertension secondary to respiratory diseases

BACKGROUND

Pulmonary hypertension (PH) secondary to respiratory disease is caused by pulmonary vascular remodeling and hypoxia. Severe PH can induce various clinical signs, including syncope and right-sided heart failure.

HYPOTHESIS/OBJECTIVES

To investigate the echocardiographic characteristics in dogs with PH secondary to respiratory diseases.

ANIMALS

Thirty-one dogs with respiratory diseases with or without PH and 15 healthy dogs.

METHODS

Prospective cross-sectional study. Dogs were classified according to respiratory disease (obstructive airway/lung disease [OALD] or restrictive lung disease [RLD]) and PH-relevant signs. The association between echocardiographic variables and PH (classified by respiratory disease and PH-relevant signs) was investigated.

RESULTS

Twenty-one dogs were diagnosed with PH; of these, 11 showed PH-related signs (OALD, n = 2; RLD, n = 9), 14 had right ventricular hypertrophy, and 19 had pulmonary arterial enlargement. Right ventricular dysfunction and dilatation were observed only in dogs with PH-related signs (n = 10). Left and right ventricular stroke volumes were significantly lower in dogs with PH (median [interquartile range]: 17.2 [12.4-20.8] and 16.8 [15.3-29.5] mL/m2 , respectively). Dogs with RLD had higher echocardiography-estimated pulmonary vascular resistance than those with OALD (median [interquartile range]: 3.1 [1.9-3.3] and 1.6 [1.3-2.2], respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Pulmonary arterial enlargement was the most common echocardiographic finding in dogs with PH secondary to respiratory diseases. Right ventricular dysfunction, dilatation, and decreased left and right ventricular stroke volume were significantly associated with the PH-related signs, indicating that comprehensive echocardiography is recommended in dogs with respiratory disease. Restricted lung disease might induce more severe PH than OALD.

Comparative Study of Inhaled Fluticasone Versus Oral Prednisone in 30 Dogs with Cough and Tracheal Collapse

Coughing is common in dogs with tracheal collapse (TC). The use of inhaled corticosteroids is less widespread than oral ones. This study aims to compare the effects of oral and inhaled corticosteroids in dogs with cough and TC. Thirty dogs were prospectively included and randomized to the prednisone oral group (OG, 14) or fluticasone inhaled group (IG, 16). A clinical score (CS) based on four clinical parameters (respiratory distress, cough episodes, cough frequency, tracheal sensitivity) was monitored at the hospital (enrolment and weeks 2 and 4). Water intake, urination habits, and adherence and tolerance to treatments were monitored weekly. Significant improvements in clinical parameters were identified in both groups throughout the study. Between-group (OG-IG) comparisons revealed no significant differences, indicating equivalent improvement. At the study's endpoint, the IG dogs had a significantly lower CS (5.69 ± 0.79) than OG dogs (6.43 ± 1.02, p < 0.05). Adherence and tolerance were comparable. From weeks 2 to 4, OG dogs were significantly thirstier and urinated more frequently than IG dogs. In conclusion, fluticasone provided good tolerability and efficacy in controlling cough in dogs with TC, and they showed a lower incidence of signs of hypercortisolism compared to prednisone. These data encourage the use of inhaled fluticasone in dogs with cough and TC.

Evaluation of cardiovascular effects of intramuscular medetomidine and a medetomidine-vatinoxan combination in Beagle dogs: A randomized blinded crossover laboratory study

OBJECTIVE

To compare the cardiovascular effects of a combination of medetomidine and vatinoxan (MVX) versus medetomidine (MED) alone administered intramuscularly (IM) and to determine whether heart rate (HR) can be used as a surrogate for cardiac output (CO) after the use of medetomidine with or without vatinoxan.

STUDY DESIGN

A randomized, blinded, experimental, crossover study.

ANIMALS

A group of eight healthy Beagle dogs aged 4.6 (2.3-9.4) years and weighing 12.9 (9-14.7) kg, median (range).

METHODS

Each dog was injected with 1 mg m-2 medetomidine with or without 20 mg m-2 vatinoxan IM with a washout period of 7 days. Cardiovascular data and arterial and mixed venous blood gas samples were collected at baseline, 5, 10, 15, 20, 35, 45, 60, 90 and 120 minutes after treatment administration. CO was measured at all time points via thermodilution. Differences between treatments, period and sequence were evaluated with repeated measures analysis of covariance and the relationship between HR and CO was assessed with a repeated measures analysis of variance; p values < 0.05 were deemed significant.

RESULTS

The CO was 47-96% lower after MED than after MVX (p < 0.0001). Increases in systemic, pulmonary arterial and right atrial pressures and oxygen extraction ratio were significantly higher after MED than after MVX (all p < 0.0001). HR was significantly lower after MED and the linear relationship to CO was significant (p < 0.0001).

CONCLUSIONS AND CLINICAL RELEVANCE

Overall, MED affected the cardiovascular system more negatively than MVX, and the difference in cardiovascular function between the treatments can be considered clinically relevant. HR was linearly related to CO, and decreases in HR reflected cardiac performance for dogs sedated with medetomidine with or without vatinoxan.

Usefulness of NT-proBNP in dogs with heartworm: could this biomarker be useful to evaluate pulmonary hypertension?

BACKGROUND

In recent years, the usefulness of echocardiography and serum biomarkers in the diagnosis of pulmonary hypertension (PH) in dogs with heartworm disease has been studied. Previously, N-terminal pro B-type natriuretic peptide (NT-proBNP) has shown high concentrations in dogs with heart disease and/or PH as well as its usefulness as a prognostic indicator, but it has never been evaluated in the diagnosis and prognosis of PH in dogs with heartworm disease. The aim was to evaluate the serum concentrations of NT-proBNP in dogs infected by Dirofilaria immitis to determine its usefulness as a tool to detect precapillary PH.

METHODS

NT-proBNP was determined in 50 heartworm-infected dogs. Presence/absence of PH was determined echocardiographically, using the Right Pulmonary Artery Distensibility Index (RPAD Index) and the systolic flow of tricuspid regurgitation mainly, together with other echocardiographic measurements following the guidelines of the American College of Veterinary Internal Medicine (ACVIM) for the diagnosis of PH. Other epidemiological parameters (breed, age, sex, status: client-owned or shelter dogs) and clinical parameters (microfilaremia, parasite burden, presence of symptoms, body condition) were collected as well.

RESULTS

Moderate-severe PH was present in 40% of the dogs (RPAD Index < 29.5%), NT-proBNP concentrations being significantly higher compared with dogs that did not have PH. A cutoff for NT-proBNP of ≥ 1178.45 pmol/l showed a sensitivity of 64.3% and a specificity of 95.5% for the presence of moderate-severe PH. Older dogs and dogs from shelters showed significantly higher NT-proBNP concentrations. Dogs with symptoms and low body condition presented significantly higher NT-proBNP concentrations as well.

CONCLUSIONS

The determination of NT-pro-BNP concentration can be a useful tool in the diagnostic work-up of dogs with heartworm disease and associated PH and can help to identify animals in the more advanced stage of this disorder.

Budd-Chiari-like syndrome in a dog secondary to a gunshot wound treated with balloon angioplasty and endovascular stent placement

A 6-year-old female spayed Chihuahua mix presented with chronic recurrent ascites. Computed tomographic angiography revealed an isolated stenosis of the caudal vena cava secondary to a metallic foreign body, resulting in Budd-Chiari-like syndrome. Balloon angioplasty and endovascular stent placement successfully resolved the obstruction with long-term resolution of ascites.

Inhibiting IL-6 in medicine: a new twist to sustain inhibition of his cytokine tin the therapy of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronic, progressive disease characterized by an increase in blood pressure in the lungs' arteries. It can occur in a variety of species, including humans, dogs, cats, and horses. To date, PAH has a high mortality rate in both veterinary and human medicine, often due to complications such as heart failure. The complex pathological mechanisms of PAH involve multiple cellular signalling pathways at various levels. IL-6 is a powerful pleiotropic cytokine that regulates several phases of immune response, inflammation, and tissue remodelling. The hypothesis of this study was that the use of an IL-6 antagonist in PAH could interrupt or mitigate the cascade of events that leads to the progression of the disease and the worsening of clinical outcome, as well as tissue remodelling. In this study, we used two pharmacological protocols with an IL-6 receptor antagonist in a monocrotaline-induced PAH model in rats. Our results showed that the use of an IL-6 receptor antagonist had a significant protective effect, ameliorating both haemodynamic parameters, lung and cardiac function, tissue remodelling, and the inflammation associated with PAH. The results of this study suggest that the inhibition IL-6 could be a useful pharmacological strategy in PAH, in both human and veterinary medicine.

Cardiovascular Effect of Epoprostenol and Intravenous Cardiac Drugs for Acute Heart Failure on Canine Pulmonary Hypertension

Pulmonary hypertension (PH) is a life-threatening complication in dogs with cardiopulmonary disease. Epoprostenol is an intravenous pulmonary vasodilator used to treat PH in humans; however, its efficacy in dogs remains unknown. We investigated the cardiovascular effects of epoprostenol and several cardiac agents for acute heart failure in canine models of chronic PH. Six dogs with chronic PH were anesthetized and underwent right heart catheterization and echocardiography before and after infusion of epoprostenol, dobutamine, dopamine and pimobendane. (The drug administration order was the same for all dogs). High-dose epoprostenol (15-20 ng/kg/min) tended to decrease pulmonary arterial pressure (PAP) while significantly decreasing pulmonary and systemic vascular resistance and increasing left and right ventricular (LV and RV, respectively) function. Pimobendan significantly increased LV and RV functions without increasing PAP. Conversely, dobutamine and dopamine significantly increased LV and RV function as well as PAP. This study revealed the efficacy of epoprostenol in treating canine PH through its pulmonary and systemic vasodilating effects. Although catecholamines improve LV and RV function, they might worsen PH pathophysiology, and careful monitoring may be necessary when using these drugs. Pimobendan improved LV and RV function without increasing PAP; however, a stronger vasodilating effect was observed with epoprostenol.

Cardiac Magnetic Resonance Imaging Detects Myocardial Abnormalities in Naturally Infected Dogs with Chronic Asymptomatic Chagas Disease

Trypanosoma cruzi infection causes inflammation and fibrosis, resulting in cardiac damage in dogs. The objectives of this study were to describe cardiac magnetic resonance imaging (CMR) in naturally infected dogs with chronic Chagas disease and the frequency of abnormalities for CMR and cardiac diagnostic tests. Ten asymptomatic, client-owned dogs seropositive for T. cruzi were prospectively enrolled in an observational study evaluating echocardiography, ECG (standard and ambulatory), cardiac troponin I (cTnI), and CMR. Standard ECG measurements (3/10) and cTnI concentration (1/10) outside the reference range were uncommon. Ambulatory ECG abnormalities were documented more frequently (6/10 dogs) than with standard ECG and included ventricular arrhythmias (4), supraventricular premature beats (3), second-degree atrioventricular block (2), and sinus arrest (1). Echocardiographic abnormalities were documented in 6/10 dogs including mildly increased left ventricular internal dimension in diastole (1) and decreased right ventricular (RV) systolic function based on reductions in tricuspid annular plane systolic excursion (3) and RV S' (4). Abnormalities were detected with CMR in 7/10 dogs including delayed myocardial enhancement in 5 of which 2 also had increased extracellular volume, abnormal wall motion in 5, and loss of apical compact myocardium in 1. In conclusion, CMR abnormalities were common, and the results of this study suggest CMR can provide useful information in dogs with T. cruzi infection and may support naturally infected dogs for future clinical investigation as an animal model for Chagas disease.

N-terminal brain natriuretic peptide, cardiac troponin-I, and point-of-care ultrasound in dogs with cardiac and noncardiac causes of nonhemorrhagic ascites

BACKGROUND

Nonhemorrhagic ascites (NHA) can be caused by cardiac diseases (cNHA) and noncardiac diseases (ncNHA). N-terminal brain natriuretic peptide (NT-proBNP), cardiac troponin-I (cTnI), and point-of-care ultrasound (POCUS) may differentiate between cNHA and ncNHA.

HYPOTHESIS/OBJECTIVES

We compared NT-proBNP and cTnI concentrations as well as POCUS findings in dogs presented with cNHA and ncNHA.

ANIMALS

Dogs (n = 60) were enrolled based on identification of NHA with an effusion packed cell volume < 10%.

METHODS

Blood samples were collected and POCUS was performed on all dogs. Dogs were diagnosed with cNHA (n = 28) or ncNHA (n = 32) based on echocardiography. The cNHA group was subdivided into cardiac non-pericardial disease (n = 17) and pericardial disease (n = 11).

RESULTS

The NT-proBNP concentration (median; range pmol/L) was significantly higher in the cNHA group (4510; 250-10 000) compared to the ncNHA group (739.5; 250-10 000; P = .01), with a sensitivity of 53.8% and specificity of 85.7% using a cut-off of 4092 pmol/L. The NT-proBNP concentrations were significantly higher in the cardiac non-pericardial disease group (8339; 282-10 000) compared with the pericardial disease group (692.5; 250-4928; P = .002). A significant difference in cTnI concentration (median; range ng/L) between the cNHA group (300; 23-112 612) and ncNHA group (181; 17-37 549) was not detected (P = .41). A significantly higher number of dogs had hepatic venous and caudal vena cava distension in the cNHA group compared to the ncNHA group, respectively (18/28 vs 3/29, P < .0001 and 13/27 vs 2/29, P < .001). Gall bladder wall edema was not significantly different between groups (4/28 vs 3/29, P = .74).

CONCLUSIONS AND CLINICAL IMPORTANCE

NT-proBNP concentration and POCUS help distinguish between cNHA and ncNHA.

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.

Echocardiographic Assessment of the Pulmonary Vein to Pulmonary Artery Ratio in Canine Heartworm Disease

Background:Dirofilaria immitis produces proliferative pulmonary endarteritis and pulmonary thromboembolism in infected dogs. The pulmonary vascular lesions lead to irreversible and persistent structural damage and, as a consequence, sustained precapillary pulmonary hypertension (PH). The purpose of this study was to assess the diagnostic value of the pulmonary vein to pulmonary artery ratio (PV:PA ratio) to determine moderate or severe PH (>50 mmHg) in dogs with heartworm disease.

METHODS

A total of 151 naturally heartworm-infected and 66 healthy dogs were included in the study. The presence/absence of PH was based on the right pulmonary artery distensibility index (RPAD index < 29.5%), and the PV:PA ratio was echocardiographically measured by the time-motion mode (M mode) and two-dimensional mode (2D mode). Other echocardiographic parameters were also assessed (pulmonary trunk to aorta ratio, tricuspid regurgitation pressure gradient, and AT:ET ratio).

RESULTS

The results of the PV:PA ratio showed a highly positive correlation between the M and 2D modes (r = 0.928). The PV:PA ratio obtained by the M mode was identified as the strongest predictor for RPAD index (R² 0.628, p < 0.0001) with a good diagnostic accuracy (AUC = 0.99). The results of PV/PA by the 2D mode showed a similar prediction for the RPAD index (R² 0.606, p < 0.0001) with a good diagnostic accuracy (AUC = 0.98). Both of the 2D and M modes' PV:PA ratios decreased significantly with the presence of PH. A cut-off value of ≤0.845 showed high sensitivity and specificity for the M mode (97% and 94%, respectively) and the 2D mode (96% and 93%, respectively).

CONCLUSIONS

The PV:PA ratio may be useful as a complementary diagnostic method for the estimation of moderate or severe PH in dogs with heartworm.