Retrospective review of congenital heart disease in 976 dogs

Effects of left vagus nerve retraction on post-operative unilateral left-sided laryngeal paralysis following surgical closure of patent ductus arteriosus in dogs

OBJECTIVES

This study was aimed at determining the incidence of left-sided laryngeal paralysis in dogs that underwent patent ductus arteriosus open surgical ligation and at identifying whether left vagus nerve retraction during surgery might be a risk factor for post-operative left-sided laryngeal paralysis development.

MATERIALS AND METHODS

Medical records for dogs referred to our clinic for surgical patent ductus arteriosus closure between July 2012 and May 2022 were reviewed. The inclusion criteria were echocardiographic diagnosis of left-to-right shunting patent ductus arteriosus, standard surgical ligation of the patent ductus arteriosus, short-term follow-up at 30 days and long-term follow-up for at least 365 days.

RESULTS

Of the 40 dogs included, left vagus nerve retraction was performed during surgical dissection in 25 dogs. All dogs survived the surgery, with full closure of the patent ductus arteriosus in 100% of cases. The overall incidence of post-operative left-sided laryngeal paralysis was 12.5%. Heavier weight was significantly associated with a greater risk of left-sided laryngeal paralysis after surgery (odds ratio = 1.19; P = 0.044). Left vagus nerve retraction during surgery was not significantly associated with left-sided laryngeal paralysis risk (P = 0.996). No dogs required arytenoid lateralisation. In long-term follow-up, 37/40 dogs remained alive at an average of 1874 days after surgery.

CLINICAL SIGNIFICANCE

Endoscopic evaluation of laryngeal function after surgical patent ductus arteriosus ligation is recommended when dogs present with inspiratory stridor, vocal changes, exercise intolerance or regurgitation post-operatively.

Echocardiographic classification of dogs with aortic stenosis: potential utility of a novel staging system

INTRODUCTION

Severity of aortic stenosis (AS) in humans is classified using a staging system based on two-dimensional echocardiographic changes, which considers the extent of global cardiac damage. Currently, classification of canine AS is based on trans-aortic pressure gradient (PG) alone. This study aimed to retrospectively classify dogs with AS based on an adapted human staging system, exploring feasibility of classification and the association between stage and features such as PG and clinical signs.

ANIMALS

This study included 87 client-owned dogs.

MATERIALS AND METHODS

Clinical and echocardiographic data were retrieved from computerised records. Dogs were classified according to a modified human staging system (Stages: 0/1/2+). Descriptive statistics were explored. Differences in signalment, PG, and clinical signs between stages were evaluated using appropriate statistical tests. Significance was identified if P<0.05 after correction for multiple comparisons.

RESULTS

Forty-one dogs were classified as Stage 0, 36 as Stage 1, and 10 as Stage 2+. No difference in signalment or weight was identified between stages. Dogs classified as Stage 2+ were more likely to have clinical signs than those in Stages 0 or 1 (50% vs. 7% [P=0.004] and 17% [P=0.043], respectively) and had a higher PG than dogs in Stage 0 (90 mmHg [35-143 mmHg] vs. 25 mmHg [18-182 mmHg], P=0.001).

CONCLUSIONS

This study presents an alternative way to classify dogs with AS. Data support further study of the staging system to compare whether or not this classification has additional value over assessment of PG alone.

Balloon aortic valvuloplasty for congenital aortic valvar stenosis in 10 dogs

INTRODUCTION/OBJECTIVES

Aortic valvar stenosis (AS) is an uncommon congenital defect in the dog, but when present, it can cause severe clinical signs including collapse and congestive heart failure. In human patients, AS is a common congenital defect that has been managed with balloon aortic valvuloplasty (BAV). The objectives of this study were to describe the procedural details and retrospectively evaluate the outcomes of dogs with severe AS that underwent BAV.

ANIMALS

Ten client-owned dogs diagnosed with severe AS.

MATERIALS AND METHODS

Medical records and stored images from echocardiographic and angiographic examinations were reviewed from dogs that were diagnosed with severe AS and underwent BAV. The severity of velocity-derived maximal systolic pressure gradient across the aortic valve and aortic insufficiency was assessed from transthoracic echocardiographic images before and after BAV. Procedural details from the BAV procedures including intra-operative complications, type and size of the balloon catheter used, and use of rapid right ventricular pacing were recorded.

RESULTS

The median (range) age and weight at the time of BAV were 12 months (6-120 months) and 18.2 kg (4.8-33.0 kg), respectively. Most dogs had high-pressure balloon dilation catheters used (n = 6/10) during BAV, and the balloon diameter-to-aortic annular ratio was 1.03 ± 0.05 for all dogs. The maximal systolic pressure gradient across the aortic valve decreased from 183.2 mmHg ± 74.6 before BAV to 97.4 mmHg ± 48.2 immediately after BAV (P<0.001). The severity of aortic insufficiency did not significantly worsen after BAV (P=0.25). The long-term impact of BAV on survival is unknown, and this could be considered a limitation of this study.

STUDY LIMITATIONS

This study describes the short-term effects of BAV for dogs with AS, and a lack of long-term follow-up may be considered a limitation.

CONCLUSIONS

Balloon aortic valvuloplasty for severe AS is tolerated in most dogs, and dogs with severe AS may benefit from transcatheter BAV.

A Comprehensive Review of Canine and Feline Ventricular Septal Defects-From Pathogenesis to Long-Term Follow-Up

Congenital heart defects (CHDs) in dogs and cats represent a definite minority of cardiac patients. One of the most commonly diagnosed is ventricular septal defects (VSDs). These are associated with abnormal ventricular septation during the prenatal period; however, the mutations of the genes responsible for this phenomenon are not fully understood. VSDs pose a significant diagnostic challenge due to the multitude of locations in the ventricular septum where they are likely to occur. Therefore, there are many phenotypes of the defect causing many problems in terms of a common nomenclature. Among the various classifications, the latest terminology issued by The International Society for Nomenclature of Paediatric and Congenital Heart Disease (ISNPCHD) considers both electrical conduction pathways and adjacent structures to standardize nomenclature. Further, defects located at different sites can alter both prognosis and subsequent management for the patient; thus, taking accurate measurements is crucial. Among these, the Qp:Qs and VSD:Ao ratios, the direction of blood flow through the defect, its location, the diameter and maximum flow velocity, and the pressure difference between the RV and LV are indicated. Emerging technologies such as 3D echocardiography and cardiac magnetic resonance may provide additional diagnostic value. Altogether, along with clinical symptoms, we should determine further management, involving the monitoring of the patient, the implementation of pharmacological treatment, or referral for surgical closure of the VSD. This review summarizes current knowledge on VSD, where the pathogenesis of the condition, diagnosis, and management, including conventional and surgical methods as well as long-term follow-up, are described, providing a complete overview of the issue.

Prevalence of Congenital Heart Diseases in Dogs in Tehran, Iran: A Retrospective Study From 2013 to 2023

Congenital heart disease (CHD) is a major health issue in dogs, contributing to both morbidity and mortality. This retrospective study reviews the epidemiological features and prevalence of CHD in dogs visiting veterinary facilities in Tehran, Iran, over the last 10 years. Medical records were analyzed for 4033 canines that underwent comprehensive cardiac examinations, including echocardiography, between January 2013 and October 2023. In this study, 88 cases of CHD were detected, and an overall prevalence of 2.18% was determined. A significant difference was noted between mixed-breed dogs (8.65%) and purebred dogs (1.63%). Pulmonary stenosis (PS) is the most commonly diagnosed CHD, followed by subaortic stenosis (SAS) and patent ductus arteriosus (PDA). CHD prevalence correlated strongly with age and gender; in particular, females and older dogs were more likely to suffer from specific CHDs. CHD is most often diagnosed without symptoms, highlighting the importance of regular screenings and careful auscultation for early detection. Future research must focus on identifying the genetic factors that make dogs more susceptible to CHDs and developing more effective methods for diagnosing and treating these conditions in canine populations. This study does not represent the general dog population in the region or the country but provides researchers with valuable insights into the epidemiology of CHD in dogs referred to veterinary hospitals in Tehran, Iran, underlining the importance of monitoring and focused therapies to improve their health and general well-being.

Cor triatriatum dexter in Dogs: A Silent Bystander or a Potential Time Bomb? A Focused Literature Review from a Professional Perspective

Congenital heart diseases (CHDs) are structural anomalies present at birth, resulting from aberrant embryonic development. In veterinary medicine, CHDs are an important reason for disease and death in both dogs and cats. Their prevalence varies across species and breeds, with certain defects being more common in specific breeds due to genetic predisposition. In this article, we will focus specifically on cor triatriatum dexter (CTD), an uncommon congenital defect that involves the division of the right atrium into two chambers by a fibromuscular membrane. This malformation can have serious consequences, depending on the severity of the obstruction created by the membrane, and the presence of the often-associated congenital anomalies. It can range from mild, clinically silent anomalies to severe defects that result in heart failure, cyanosis, or sudden death. The present review aims to (i) explore the pathophysiology of CTD in dogs; (ii) outline the clinical scenario underlying the increased interest in CHDs by overviewing the evolution of appropriate diagnostic techniques and the treatment options available; and (iii) provide a discussion from a medical-legal and ethical point of view.

Retrospective Evaluation of End-Diastolic Forward Flow and Restrictive Physiology in One Hundred and Sixty-Four Dogs with Pulmonary Stenosis

The study of the function of the right ventricle (RV) is a topic of great interest in the scientific community, and some studies have evaluated parameters of the right ventricular systolic function and have correlated them to various RV pathologies and possible clinical findings. Less information was obtained on the right ventricular diastolic function. In veterinary medicine, the characteristics of the restrictive RV and the presence of end-diastolic forward flow (EDFF) in patients with pulmonary stenosis have not yet been described. This type of flow is an antegrade flow that is observed with the Doppler study of the pulmonary artery and occurs at the end of the diastolic phase. Pulmonary valve stenosis (PVS) is one of the most common congenital heart diseases in dogs. The echocardiographic parameter that is mainly taken as a reference for evaluating the severity of the disease is the peak gradient of the pulmonary antegrade flow. For our retrospective study, we consider a total of 164 dogs with PVS divided into 149 dogs with type A and 15 type B, seen at a reference veterinary clinic from 2020 to 2024. All these dogs underwent echocardiographic examinations to observe the morphological characteristics of the PVS and consider the presence or absence of restrictive RV with EDFF. An independent sample t-test analysis revealed that the severity of PVS is greater in dogs with EDFF, both in the group of patients with type A stenosis and in patients with type B stenosis. This study suggests that RV restrictive physiology is common in dogs with severe PVS.

Congenital pulmonic and aortic stenosis in Newfoundland dogs: Results of a 14-year French cardiovascular screening program (921 dogs)

INTRODUCTION

Aortic stenosis (AS) and pulmonic stenosis (PS) are two of the most common canine congenital heart diseases (CHD), with a high relative risk for Newfoundland dogs to develop inherited subvalvular AS. For this reason, a cardiovascular screening program has been set up by the French Newfoundland kennel club in order to manage mattings and reduce AS prevalence.

MATERIALS AND METHODS

The records of untreated and non-anesthetized adult Newfoundland dogs screened between 2010 and 2023 were retrospectively reviewed. All dogs underwent physical examination and standard transthoracic echocardiography with concomitant ECG tracing. All examinations were reviewed by one single board-certified specialist in cardiology.

RESULTS

A total of 921 dogs were screened during the study period (female:male sex ratio = 1.94, median age [IQR] = 1.9 years [1.6-2.7], body weight = 55.0 kg [50-60]). For most dogs (90.6% for AS and 91% PS), a single examination was required to obtain a definitive cardiac status, although most operators (122/133 = 91.7%) were non-specialist general practitioners. Out of the 921 screened dogs, 913/921 (99.1%) and 919/921 (99.8%) were respectively free of AS and PS, with no AS and PS detection during the last 3 years of the program. The inbreeding coefficient, which was assessed from the pedigree analysis of all screened dogs except one, was not significantly different between dogs with either AS (0.59%; P = 0.86) or PS (0.39%; P = 0.72) and those without any arterial stenosis (0.39%).

CONCLUSION

This 14-year cardiovascular screening program has experienced a strong involvement of veterinarians, breeders, and owners throughout France. Unlike reports from other European and North American countries, this program suggests the low and decreasing prevalence of both AS and PS in the Newfoundland breed in France.

Transvenous closure of patent ductus arteriosus with Nit-Occlud® PDA occlusion system in 13 dogs weighing less than 3 kg

INTRODUCTION

Successful closure of patent ductus arteriosus (PDA) can be obtained with surgical ligation or with occlusion via minimally invasive per-catheter techniques. This study was performed to assess feasibility and effectiveness of transjugular PDA occlusion in dogs weighing < 3 kg with a device called Nit-Occlud® PDA.

ANIMALS

Thirteen client-owned dogs.

MATERIALS AND METHODS

This was a retrospective study. Clinical records of dogs that underwent PDA occlusion with a Nit-Occlud® PDA were reviewed. Data collection included patients' signalment, clinical findings, pre- and post-procedure echocardiographic measurements, device size, procedure time and clinical outcome.

RESULTS

The median age of these patients was six months (2.5-38.0 months), with a mean body weight of 2.44 ± 0.43 kg. The mean minimal ductal diameter (MDD) was 1.82 ± 0.43 mm, while the mean ampulla diameter (AD) was 5.51 ± 1.89 mm. Duct closure was successful in 12 cases. Minimal or no residual shunt was observed on echocardiography prior to device release. In one dog, the device was not released owing to unsatisfactory occlusion, prompting an alternative occlusion method. Follow-up echocardiographic examinations showed complete ductal closure and reversed cardiac remodelling in all cases where the device was successfully released.

DISCUSSION

The Nit-Occlud® is deployed through a delivery system with an outer diameter of 4 Fr or 5 Fr, which makes this solution particularly attractive in patients where vascular access is challenging or unfeasible due to the small size of their vessels.

CONCLUSIONS

The Nit-Occlud® PDA appears a feasible and effective occlusion system in small patients weighing <3 kg.

Agreement of echocardiographic and catheterization-based methods of transpulmonary pressure gradient measurement in dogs

INTRODUCTION/OBJECTIVES

Doppler echocardiographic estimation of transpulmonary pressure gradient (PG) is widely used to determine severity of pulmonary valve stenosis and indication for transcatheter intervention. The objective of this study was to describe agreement between Doppler echocardiographic methods of transpulmonary PG estimation and direct peak-to-peak pressure gradient at catheterization (PGcath) in dogs. We hypothesized that with reference to PGcath, mean echocardiographic PG (PGecho-mean) would have less bias than peak modal instantaneous echocardiographic PG (PGecho-peak).

ANIMALS

Client-owned dogs with congenital pulmonary valve stenosis that underwent balloon pulmonary valvuloplasty at one of two veterinary teaching hospitals between June 2012 and May 2022 were included in this study.

MATERIALS AND METHODS

Cases that underwent transthoracic echocardiography and subsequent balloon pulmonary valvuloplasty separated by 30 or fewer days were retrospectively identified. For each echocardiogram, average PGecho-mean (mmHg) and average PGecho-peak (mmHg) were calculated from stored spectral Doppler recordings. Peak right ventricular-to-peak pulmonary artery PG data (mmHg) were obtained from catheterization reports. Bland-Altman analysis was used to assess agreement between echocardiographic and catheterization data.

RESULTS

Data from 209 dogs (n = 215 instances) were evaluated. Proportional bias, greater at higher gradients, was observed for PGecho-mean versus PGcath (P<0.001). A constant bias of -38.12 mmHg was observed for PGecho-peak versus PGcath (P=0.62). Bias for both echocardiographic variables had wide limits of agreement that increased with PG.

CONCLUSIONS

Mean Doppler echocardiographic systolic transpulmonary pressure gradient and PGecho-peak underestimated and overestimated PGcath, respectively, preventing their interchangeability with PGcath.

Complete atrioventricular canal in a dog-sounds like a final judgment but is it actually one? A case report

Congenital heart disease (CHD) is an important subset of all cardiovascular diseases in dogs. Among them, there are a number of other less commonly described congenital malformations. One of these is the atrioventricular canal, which involves a defect that has several phenotypes. This report details a case of a complete atrioventricular canal (cAVC) defect. Using Rastelli's classification scheme, the diagnosis of a type-A cAVC defect was based on two-dimensional, contrast, and color Doppler echocardiography. Despite a severe defect that resulted in the atypical anatomy of the atrioventricular apparatus, as well as significant hemodynamic changes in the heart, the affected dog remained asymptomatic throughout the 48-month follow-up period. Due to its stable clinical condition, the decision was made not to begin pharmacological therapy. As this defect is rare in dogs, there are limited data in the literature on this condition. Therefore, in clinical practice, the management and monitoring of the patient may pose difficulties. Due to such limited data, it can be very difficult to provide a prognosis. For the above reasons, we hope that the following case will contribute valuable information for the monitoring of this kind of CHD.

Case report: Eisenmenger syndrome in a dog with ventricular septal defect: long term management and complications

A 9-month-old female Jack Russell Terrier was referred because of two episodes of suspected syncope. Echocardiography revealed a large, isolated mid-muscular ventricular septal defect (7 mm) with bidirectional shunting. A diagnosis of Eisenmenger syndrome and erythrocytosis (68.5% of hematocrit) was made and sildenafil therapy (0.5 mg/Kg twice daily) was initiated. Regular follow-up examinations were performed and Sildenafil therapy was gradually increased based on changes in clinical signs, packed cell volume and heart rate. The dog's clinical conditions have been stable without the need of phlebotomy for 4 years and 6 months, until April 2021 (month 74) (about 7 years of survival) when the dog had 80% of hematocrit and signs of hyperviscosity syndrome. The dosage of administered sildenafil reached gradually 6 mg/Kg DIE (2 mg/Kg three times a daily) in June 2022. Lastly, in November 2023 a closed pyometra was diagnosed and the dog was hospitalized and operated. The major concerns in the peri-operative period were hypotension and the profound hypoxemia, but the dog was discharged and recovered normal activity in approximately 11 days. This report describes the long-term management with sildenafil citrate of Eisenmenger syndrome secondary to a muscular ventricular septal defect with right-to-left shunting in a dog. Sildenafil therapy was always well tolerated with no side effects reported, even at higher dosage and drastically reduced the need for phlebotomy.

Percutaneous transcatheter right atrial stent placement for recurrent cor triatriatum dexter following initial surgical excision of right intra-atrial membrane in a dog

A four-year-old spayed female Shiba Inu dog weighing 6.1 kg presented with ascites. Cor triatriatum dexter (CTD) without any other concurrent cardiovascular anomalies was diagnosed using echocardiography. The ostium of the abnormal membrane dividing the right atrium into two abnormal chambers was surgically excised under cardiopulmonary bypass. All clinical abnormalities were resolved after surgery. However, seven months later, ascites and CTD recurred. A balloon-expandable stent was placed at the site of recurrence, which improved caudal venous return to the right ventricle. After the second procedure, ascites were resolved, and the dog remained asymptomatic for 18 months without complications. There are previous reports of successful surgical resection of the CTD and of stenting in recurrent CTD following balloon dilation in dogs. However, to the authors' knowledge, no previous reports have described recurrent CTD in dogs after surgical resection of the CTD. In this case, as with recurrent CTD following balloon dilation, stent placement at the site of the CTD can be a viable treatment option when the abnormal membrane recurs.

Trans-pulmonary stent placement for pulmonary stenosis in a dog with a type R2A coronary artery anomaly

A one-year-old male intact American bulldog was presented for evaluation of previously diagnosed pulmonary stenosis. Echocardiography identified ultra-severe stenosis with an instantaneous trans-pulmonary pressure gradient of 240 mmHg. Angiography confirmed the presence of an anomalous coronary artery with a prepulmonic course of the left coronary artery arising from a single right coronary ostium consistent with a type R2A coronary anomaly. A trans-pulmonary stent was successfully placed transvenously with diameter sizing based on coronary compression testing. No coronary compression was present on postimplantation angiography. A marked reduction in the pressure gradient was obtained on postoperative echocardiography (reduction to 68 mmHg), despite selecting a stent diameter less than the pulmonary annulus diameter. This is the first report of the use of coronary compression testing in transvenous trans-pulmonic stent implantation in a dog with a type R2A coronary artery anomaly. Selection of a stent diameter less than the pulmonary annulus diameter conveyed a clinically relevant reduction in the trans-pulmonic pressure gradient while avoiding coronary compression in this case.

Correlation of transthoracic echocardiographic and angiographic measurements of pulmonary valve annular diameter in dogs with pulmonary stenosis

INTRODUCTION/OBJECTIVES

Dogs with severe pulmonary stenosis (PS) are routinely treated with balloon valvuloplasty. Success and safety of these procedures require an accurate assessment of the pulmonary valve annulus (PVA) diameter for proper balloon catheter selection. PVA diameter is assessed with angiography (PVA-Ang) and transthoracic echocardiography (PVA-TTE), and both may impact procedural planning for balloon valvuloplasty. The objective of this study was to describe the relationship between PVA-Ang and PVA-TTE in dogs with PS.

ANIMALS, MATERIALS AND METHODS

Observational, retrospective study of 59 client-owned dogs. Medical records of dogs diagnosed with PS were reviewed. Images from selective right ventricular angiography and transthoracic echocardiography were reviewed. The PVA diameters were measured at the time of angiography (PVA-Ang) and by a single operator for this study (PVA-TTE). Image quality scores were assigned to echocardiographic images of the PVA based on visualization of PVA margins and valve leaflet hinge points.

RESULTS

In 41/59 (70%) dogs, the diameter of the PVA-Ang was larger than the PVA-TTE, and the (range 0.1 to 8.4 mm) worse echocardiographic image quality, the difference in measurement between modalities increased. Dogs with poor echocardiographic image quality had greater differences (range -7.7 to 8.4 mm) between PVA-Ang and PVA-TTE compared to those with excellent image quality (range -2.2 to 3.8 mm), and the absolute differences between poor (median 2.8 mm, range 1.5-8.4 mm) and excellent (median 1.4 mm, 0.2-3.8 mm) image quality were significant (P=0.005).

CONCLUSIONS

Diameters of PVA-Ang are greater than PVA-TTE in most dogs, and these differences are most apparent with worse echocardiographic image quality. These differences may be clinically relevant to interventional procedure planning.

Self-Reported Management of Incidentally Detected Heart Murmurs in Puppies: A Survey among Veterinarians

BACKGROUND

Heart murmurs in puppies can be innocent or pathologic; the latter is almost always related to a congenital heart disease. Differentiating between these murmurs can be challenging for practicing veterinarians, but this differentiation is essential to ensure the best prognosis for puppies having a congenital heart disease. Our study aimed to reveal how veterinarians manage puppies with a heart murmur.

METHODS

A web-based questionnaire was sent to Dutch and Belgian veterinary practices.

RESULTS

Data from 452 respondents were analyzed. Though 88% of the respondents find detecting a heart murmur easy, only 9% find differentiating innocent murmurs from pathologic murmurs in puppies easy. Of the respondents, only 80% recommend immediate additional examination when detecting a loud heart murmur during the first veterinary health check at 6 weeks of age. Most of the respondents are aware that normal growth and the absence of clinical signs do not exclude severe congenital heart disease. Of the respondents, 31% were uncertain whether early surgical intervention could lead to improved outcomes.

CONCLUSIONS

Veterinarians are aware of the importance of echocardiography for puppies with a loud heart murmur, and recognize their limitations when differentiating an innocent from a pathological heart murmur in a puppy.

Doppler Ultrasonographic Assessment of Abdominal Aortic Flow to Evaluate the Hemodynamic Relevance of Left-to-Right Shunting Patent Ductus Arteriosus in Dogs

In this multicenter, prospective, observational study, abdominal aortic flow was examined with pulsed-wave Doppler ultrasound in dogs with a left-to-right shunting patent ductus arteriosus (PDA) and in apparently healthy dogs. Forty-eight dogs with a PDA and 35 controls were included. In the dogs with a PDA, 37/48 had hemodynamically significant PDAs (hsPDAs) while 11/48 had non-hsPDAs, based on the presence or absence of echocardiographic signs of left-sided volume overload, respectively. In 12 dogs (4/35 control dogs, 7/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA), the diastole was too short to visualize the end-diastolic flow. Antegrade end-diastolic flow was observed in 30/35 controls and 6/11 dogs with a non-hsPDA. Absent end-diastolic flow was observed in 1/35 control dogs and 3/11 dogs with a non-hsPDA. Retrograde end-diastolic flow was observed in 30/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA. Twenty-one dogs (15 with an hsPDA and 6 with a non-hsPDA) were reassessed after PDA closure, and, in 19/21, end-diastolic flow was visualized: 17/19 showed an antegrade flow, 1/19 an absent flow and 1/19 a retrograde flow. Sensitivity and specificity of retrograde end-diastolic flow for detection of hsPDAs were 100% and 90%, respectively. In conclusion, ultrasonographic assessment of abdominal aortic flow was feasible in dogs with PDA. However, end-diastolic flow was not always visualized. The presence of a retrograde end-diastolic flow was an accurate finding for discriminating hsPDAs and non-hsPDAs.

Surgical Correction of a Sinus Venosus Atrial Septal Defect with Partial Anomalous Pulmonary Venous Connections Using Cardiac Computed Tomography Imaging and a 3D-Printed Model

Sinus venosus atrial septal defects (SVASDs), concurrent with partial anomalous pulmonary venous connections (PAPVCs), are a rare congenital heart disease in dogs. Surgical correction is essential when clinical signs or significant hemodynamic changes are present. We aimed to report on the successful surgical correction of an SVASD with PAPVCs, using a computed tomography (CT)-based customized 3D cardiac model. A 10-month-old male poodle was referred for corrective surgery for an ASD. Echocardiography confirmed a hemodynamically significant left-to-right shunting flow through an interatrial septal defect and severe right-sided heart volume overload. For a comprehensive diagnosis, a CT scan was performed, which confirmed an SVASD with PAPVCs. A customized 3D cardiac model was used for preoperative decision-making and surgical rehearsal. The defect was repaired using an autologous pericardial patch under a cardiopulmonary bypass (CPB). Temporary pacing was applied for sinus bradycardia and third-degree atrioventricular block. The patient recovered from the anesthesia without further complications. The pacemaker was removed during hospitalization and the patient was discharged without complications 2 weeks post-surgery. At the three-month follow-up, there was no shunting flow in the interatrial septum and the right-sided volume overload had been resolved. The cardiac medications were discontinued, and there were no complications. This report indicates the validity of surgical correction under CPB for an SVASD with PAPVCs, and the advantages of utilizing a CT-based 3D cardiac model for preoperative planning to increase the surgical success rate.

Evaluation of Alacepril Administration in Canine Patent Ductus Arteriosus According to Plasma Chymase Activity

Chymase in the renin-angiotensin system (RAS) actively contributes to cardiac disease progression. Chymase is activated to produce angiotensin II during tissue injury and is involved in hemodynamics. A recent study demonstrated that plasma chymase activity reflects hemodynamic changes and aids in understanding patent ductus arteriosus (PDA) pathophysiology. The present study examined the relationship between plasma chymase activity and the administration of angiotensin-converting enzyme (ACE) inhibitor. Alacepril was administered to 13 puppies with PDA. Conventional echocardiographic parameters and non-invasive blood pressure were measured before and after medication. Plasma chymase activity was calculated using the colorimetric absorbance method. Plasma chymase activity significantly increased, but blood pressure significantly decreased. We detected an increase in plasma chymase activity due to ACE inhibition in PDA cases treated with alacepril. Plasma chymase activity was affected and altered by alacepril. In veterinary medicine, plasma chymase activity may be a novel method for assessing the pathology of and therapy for cardiac diseases.

64-Slice ECG-gated computed tomographic angiography for assessment of coronary arteries in brachycephalic dogs with pulmonary stenosis

BACKGROUND

Brachycephalic dogs with pulmonary stenosis are known to have a higher incidence of concurrent coronary artery abnormalities than non-brachycephalic breeds, which increases risk when performing balloon valvuloplasty. The use of ECG-gated CT angiography has been reported for the evaluation of coronary arteries in normal dogs and dogs with pulmonary stenosis. The purpose of this study was to report findings of coronary artery origination and morphology of main branches using ECG-gated CT angiography in brachycephalic dogs with pulmonary stenosis.

METHODS

An ECG-gated CT angiographic protocol was used to image coronary artery anatomy in nine brachycephalic dogs with pulmonary stenosis. Images were assessed for quality as well as coronary artery morphology by one veterinary radiologist, one veterinary cardiologist and one veterinary radiology resident.

RESULTS

All nine dogs had good to excellent image quality. Coronary artery anomalies were identified in three of nine dogs: one R2A anomaly, one L2A anomaly and one L2C anomaly. Two dogs were assessed to be poor balloon valvuloplasty candidates based on CT angiographic images.

LIMITATION

Coronary artery morphology was not confirmed via postmortem examination in all patients.

CONCLUSION

ECG-gated CT angiography is a minimally invasive imaging modality capable of diagnosing various coronary artery anomalies in brachycephalic dogs with pulmonary stenosis and aiding in the determination of patient candidacy for balloon valvuloplasty.

Large Secundum Atrial Septal Defect Managed Conservatively in an Adult Dog

•ASDs can be medically managed in dogs if interventional options are not selected. •3D modeling can be used for canine congenital heart disease. •3D imaging helps with preprocedural planning for ASD.

Transesophageal echocardiography using a microprobe for determination of transcatheter procedural candidacy, device selection, and procedural monitoring in small dogs with patent ductus arteriosus

INTRODUCTION

Small dogs with patent ductus arteriosus (PDA) may be unable to undergo transesophageal echocardiography (TEE) with traditional probes.

OBJECTIVES

To report the utility of TEE using a microprobe in dogs weighing less than 4 kg diagnosed with PDA for determination of transcatheter procedural candidacy, device selection, and intraoperative procedural guidance.

ANIMALS

Eight dogs weighing less than 4 kg diagnosed with PDA.

MATERIALS AND METHODS

All dogs had standard transthoracic echocardiography and microprobe TEE imaging. The quality of TEE images was graded as optimal, adequate, or poor. The ability of TEE to assess PDA anatomy, determine procedural candidacy, provide procedural guidance, detect deployed devices, and assess residual flow was recorded.

RESULTS

The median age of included dogs was 6.4 months (range: 3.2-15.7 months) and the median body weight was 2.2 kg (range: 1.4-3.8 kg). Microprobe TEE images were adequate or optimal in all dogs and were integral for guiding procedural candidacy decisions. Transcatheter procedures were not pursued in two dogs based on TEE images. In the other six dogs, TEE procedural guidance was useful during transvenous (n = 5) and transarterial (n = 1) PDA occlusion attempts. Each deployed device (n = 4) was easily detected with the TEE microprobe. Real-time confirmation of adequate device sizing and placement was possible prior to release and residual flow could be monitored after release.

CONCLUSIONS

Transesophageal echocardiography using a microprobe in dogs weighing less than 4 kg diagnosed with PDA allowed for characterization of PDA anatomy and determination of transcatheter procedural candidacy. Microprobe TEE images were integral for PDA device selection and offered valuable intraoperative procedural guidance.

Two- and three-dimensional transesophageal echocardiographic assessment and successful occlusion of a window-like patent ductus arteriosus in two dogs

A 16-month-old Labrador-poodle cross (case 1) and a 3-month-old German shorthaired pointer (case 2) were referred for patent ductus arteriosus (PDA) occlusion. Two-dimensional transthoracic and two- and three-dimensional transesophageal echocardiography revealed a window-like PDA characterized by a wide and short ductus. Due to the atypical PDA morphology with no ampulla in case 1, ductal occlusion was attempted with non-canine-specific Amplatzer occluder devices. However, these were too small and failed to remain stable. Amplatz Canine Duct Occluder (ACDO) devices were used with success in both cases. Due to the defects' morphology, the proximal ACDO disc protruded into the aorta but there were no signs of obstruction to aortic blood flow 16 months (case 1) and 1 month (case 2) post-occlusion. We describe two cases of a window-like type PDA that were successfully occluded with an ACDO.

A Retrospective Cohort Evaluation of Left Ventricular Remodeling, Perioperative Complications and Outcome in Medium and Large Size Dogs with Patent Ductus Arteriosus after Percutaneous Closure

This retrospective cohort study included one hundred fifty-seven medium and large-size dogs with the aim of evaluating the effect of signalment and echocardiographic features on complications, outcomes and left ventricular modifications before and after patent ductus arteriosus (PDA) closure. The patients were divided in two groups based on the heart remodeling after closure: Group A included dogs that had a reduction in the end-systolic volume index (ESVI) after closure compared to the ESVI measured before; Group B included dogs without a reduction in ESVI after closure. Body weight, minimal ductal diameter (MDD) of PDA, end-diastolic volume index and presence of arrhythmias at presentation were significantly higher in Group B compared to Group A. The shortening fraction and ejection fraction after closure were reduced in both groups, but in Group B there was a major reduction, and the mean values indicated a possible systolic dysfunction. Complications during the procedure and death due to cardiac reasons were greater in Group B compared to Group A. In conclusion, a higher body weight, a larger MDD, a more severe heart enlargement or arrhythmias at presentation increased the risk of developing a worsening structural and functional condition after ductal closure, and this can be associated with perioperative complications and cardiac death.

Mitral Valve Repair-The Development and Rise of Options in the Veterinary World

Both open surgical repair and a hybrid-interventional option are now available for mitral valve repair (MVR) at select veterinary centers worldwide, making the need for awareness of options and the intricacies around case selection of increasing importance. This article will overview both options currently available and their current stages of progress.

Evaluation of right ventricular diastolic function, systolic function, and circulating galectin-3 concentrations in dogs with pulmonary stenosis

BACKGROUND

Cardiovascular diseases with increased right ventricular (RV) afterload induce RV diastolic and systolic dysfunction, and myocardial fibrosis in humans. Studies in dogs with pulmonary stenosis (PS) evaluating RV diastolic function and markers of myocardial fibrosis are lacking.

HYPOTHESIS/OBJECTIVES

Dogs with PS have echocardiographic evidence of RV diastolic and systolic dysfunction and increased serum concentrations of galectin-3 (Gal-3), a surrogate biomarker for myocardial fibrosis.

ANIMALS

Forty client-owned dogs (10 controls, 30 with PS).

METHODS

Prospective study. All dogs had systemic blood pressure measurement, serum biochemical analysis, echocardiography, and measurement of serum Gal-3 concentration performed.

RESULTS

Variables of RV diastolic function were obtained in 39/40 dogs. Trans-tricuspid flow velocity in early diastole to trans-tricuspid flow velocity in late diastole ratios (RV E/A) were lower (P < .001) in dogs with PS (median, 0.94; range, 0.62-2.04) compared to controls (1.78; 1.17-2.35). Trans-tricuspid flow velocity in early diastole to tricuspid annular myocardial velocity in early diastole ratios (RV E/e') were higher (P < .001) in dogs with PS (11.55; 4.69-28) compared to control (6.21; 5.16-7.21). Variables of RV systolic function were lower in dogs with PS (P = <.001). Serum Gal-3 concentration was higher (P = .002) in dogs with PS (285.1 pg/mL; 94.71-406.97) compared to control dogs (162.83 pg/mL; 52.3-232.82).

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with PS have RV diastolic and systolic dysfunction, and increased Gal-3 concentrations. These findings suggest the presence of RV myocardial fibrosis in dogs with PS, which could impact clinical management.

Advances in the Treatment of Pulmonary Valve Stenosis

Pulmonary valve stenosis represents the most common congenital heart defect of dogs and appears to be increasing in prevalence due to the growing popularity of brachycephalic breeds. Current treatments include beta-blockade and balloon pulmonary valvuloplasty, though evidence-based approaches to this disease are lacking. Balloon pulmonary valvuloplasty is most effective for fused, doming valves leaving a large population of dogs with thick, dysplastic valves that fail to respond adequately to balloon dilation. Transpulmonary stent implantation is an emerging therapy to consider for dogs with valve dysplasia or who have failed balloon pulmonary valvuloplasty; current experience with transpulmonary stent implantation is provided.

The Genetics of Canine Pulmonary Valve Stenosis

There have been recent advancements in understanding the genetic contribution to pulmonary valve stenosis (PS) in brachycephalic breeds such as the French Bulldog and Bulldog. The associated genes are transcriptions factors involved in cardiac development, which is comparable to the genes that cause PS in humans. However, validation studies and functional follow up is necessary before this information can be used for screening purposes.

Subvalvular Aortic Stenosis: Learning From Human and Canine Clinical Research

Subvalvular aortic stenosis (SAS) is the most common congenital heart disease (CHD) in dogs and is also prevalent in human children. A fibrous ridge below the aortic valve narrows the left ventricular outflow tract (LVOT) and increases blood flow velocity, leading to devastating side effects in diseased patients. Due to the similarities in presentation, anatomy, pathophysiology, cardiac development, genomics, and environment between humans and dogs, canine SAS patients represent a critical translational model of human SAS. Potential adverse outcomes of SAS include arrhythmias, left-sided congestive heart failure, endocarditis, exercise intolerance, syncope, and sudden cardiac death. The greatest divergence between canine and human SAS clinical research has been the standard of care regarding treatment of these outcomes, with pharmacological intervention dominating best practices in veterinary medicine and surgical intervention comprising the standard practice for human SAS patients. Regardless of the species, the field has yet to identify a treatment option to prevent disease progression or permanently remove the fibrous ridge, but historical leaps in SAS research support a continued translational approach as the most promising method for achieving this goal.

Prophylactic use of a lidocaine constant rate infusion versus saline in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis: A randomized control trial

OBJECTIVE

To evaluate the effect of a prophylactic lidocaine constant rate infusion (CRI) on the incidence and malignancy of catheter-induced ventricular ectopic complexes (VECs) during balloon valvuloplasty for management of pulmonic stenosis in dogs.

STUDY DESIGN

Single-centre, prospective, randomized study.

ANIMALS

Client-owned dogs (n = 70) with pulmonic stenosis.

METHODS

Dogs were randomly assigned to one of two anaesthetic protocols: administration of lidocaine 2 mg kg-1 bolus followed by a CRI (50 μg kg-1 minute-1; group LD) or a saline placebo (group SL) during balloon valvuloplasty. All dogs were premedicated with methadone (0.3 mg kg-1) intramuscularly and a digital three-lead Holter monitor was applied. Anaesthetic co-induction was performed with administration of alfaxalone (2 mg kg-1) and diazepam (0.4 mg kg-1), and anaesthesia was maintained with isoflurane vaporised in 100% oxygen. CRIs were started on positioning of the dog in theatre and discontinued as the last vascular catheter was removed from the heart. All dogs recovered well and were discharged 24 hours postoperatively. Blinded Holter analysis was performed by an external veterinary cardiologist using commercially available dedicated analysis software; p < 0.05.

RESULTS

Of the 70 dogs enrolled in the study, 61 were included in the final analysis: 31 in group LD and 30 in group SL. There was no significant difference between sinus beats (p = 0.227) or VECs (p = 0.519) between groups. In group LD, 19/31 (61.3%) dogs had a maximum ventricular rate ≥250 units and 20/30 (66.7%) dogs in group SL (p = 0.791).

CONCLUSION AND CLINICAL RELEVANCE

In this study, the use of a prophylactic lidocaine bolus followed by CRI in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis did not significantly decrease the incidence nor the malignancy of VECs during right heart catheterization compared with a saline CRI.

Cardiological Reference Intervals in Adult American Staffordshire Terrier Dogs

The aim of this study was to determine reference intervals (RI) for echocardiography, electrocardiography (ECG), vertebral heart score (VHS) measurement, and arterial systolic blood pressure (SBP) in American Staffordshire Terrier dogs. The study population included 29 clinically healthy AST dogs of different ages, genders, and body weights. SBP measurement, ECG, thoracic radiography, and echocardiography were performed on each dog. Compared to RIs available for the general population of dogs, the duration of the P wave and QRS complex was longer and VHS was higher. Moreover, the left ventricular dimension in diastole and systole, left atrial dimension, and end point to septal separation values were higher, while the interventricular septum in diastole and systole and aortic root diameter were lower compared to general similar average body weight. The AST breed has a different heart shape, which in this breed is more rounded compared to other dog breeds, especially the deep chest. The specific body structure and the shape of the heart had an impact on the results of the cardiological examination.

Case report: Imaging features of aorta-right atrial tunnel in a dog using two-dimensional echocardiography and computed tomography

A 7-year-old castrated male Pomeranian dog weighing 5 kg presented with a right-sided continuous murmur without any clinical signs. Thoracic radiographs indicated cardiomegaly and right atrial (RA) bulging. Echocardiography revealed a tunnel originating from the right coronary sinus of Valsalva and terminating in the RA. Contrast echocardiography revealed pulmonary arteriovenous anastomoses. Computed tomography (CT) demonstrated a tortuous shunting vessel that originated from the aorta extending in a ventral direction, ran along the right ventricular wall, and was inserted into the RA. Based on these diagnostic findings, the dog was diagnosed with the aorta-RA tunnel. At the 1-year follow-up visit without treatment, the dog showed no significant change except for mild left ventricular volume overload and mildly decreased contractility. To the best of our knowledge, this is the first case report of an aorta-RA tunnel that has been described in detail using echocardiography and CT in a dog. In conclusion, the aorta-RA tunnel should be included in the clinical differential diagnoses if a right-sided continuous murmur is heard or shunt flow originating from the aortic root is identified.

Cardiac Disease and Screening in Breeding Dogs

Acquired and congenital heart diseases are relatively common in dogs, particularly in certain breeds. Modes of inheritance and genetic causes have been established for several cardiac diseases within various breeds. Breed screening is used to try and reduce the prevalence of certain canine cardiac diseases. Although breed screening seems to help reduce the prevalence of canine heart disease, the outcomes of specific breeding programs are variable and depend on multiple factors.

Stents in Veterinary Medicine

Stenting in veterinary medicine has been a rapidly growing method of interventional surgery for several years. This procedure is usually performed in the respiratory and urinary tracts, but there are cases of stenting of blood vessels or gastrointestinal structures. It is based on maintaining the permeability of a given tubular structure, thus allowing the passage of gas or liquid. This procedure is often performed as a first-line treatment in situations where pharmacological agents do not work and as an alternative method, often cheaper than the classically performed ones. There are also cases where stenting is used as a palliative treatment, e.g., to enable defecation in colonic obstruction due to tumour infiltration of the colon wall. Stenting is often a life-saving or comfort-improving procedure for animals, but one should also be aware of possible postoperative complications and be prepared for any adversity. For this reason, this review provides an insight into the current knowledge in veterinary medicine about stenting and the consequences associated with this procedure.

Integrative echocardiographic assessment of post-operative obstruction severity and restenosis after balloon valvuloplasty in 81 dogs with pulmonary stenosis

INTRODUCTION/OBJECTIVES

Pulmonary stenosis (PS) is a congenital defect in the dog that is managed with balloon valvuloplasty (BV). Obstruction severity is routinely assessed using transthoracic echocardiography. The objectives of this study were to describe the short-term changes and long-term restenosis by retrospectively evaluating flow-dependent and flow-independent echocardiographic variables for dogs with PS after BV.

ANIMALS, MATERIALS, AND METHODS

Medical records and stored echocardiographic images were reviewed from dogs that received BV for PS. The following echocardiographic variables were measured or calculated: maximum systolic ejection velocity (Vmax_PV) and velocity-derived maximal pressure gradient (PV maxPG) across the pulmonary valve; ratio of aortic to pulmonary velocity time integral (VTI_AV/VTI_PV); ratio of aortic to pulmonary maximal velocity.

RESULTS

Eighty-one dogs with PS that had a BV were included. Each of these dogs had pulmonary obstruction severity assessed in at least three timepoints. Forty-nine dogs had at least one additional examination performed, the last of which occurred a median of 504 days after the BV. Echocardiographic variables at the first follow-up had increased by a clinically relevant quantity in 20-34% of the dogs when comparing to the immediate post-BV examination. The last follow-up examination identified valve restenosis in 18-38% of the dogs in this study. Valve type and pre-BV obstruction severity did not have a significant effect (P > 0.1).

CONCLUSIONS

For the assessment of BV efficacy, the immediate post-BV echocardiogram may not be as useful as the first follow-up examination several months later. Pulmonary restenosis after BV may be more prevalent than previously reported.

Evaluation of two probes for transesophageal echocardiography in small dogs: imaging capabilities, image quality, and usability

INTRODUCTIONS

Patient size is a limiting factor for transesophageal echocardiography (TEE) in small dogs. The objective of this study was to describe imaging capabilities of two probes for TEE in small dogs.

ANIMALS, MATERIALS, AND METHODS

Prospective study in 10 client-owned dogs weighing <4 kg with congenital heart disease (CHD). Dogs had TEE performed with a microprobe (10T-D, GE Medical) and intracardiac echocardiography (ICE) catheter-based probe (AcuNav™, Biosense Webster) in the esophagus in alternating order. Ease of placement, ability to acquire images of the CHD, image quality, and probe limitations were recorded.

RESULTS

Median weight was 2.4 kg (range, 1.0-3.2). Congenital abnormalities included patent ductus arteriosus (n = 9) and pulmonary valve stenosis (n = 1). The 10T-D microprobe was easy to place (n = 8) or achievable with gentle manipulation (n = 2), and image quality of the CHD was optimal (n = 8), adequate (n = 1), or poor (n = 1). The ICE probe was difficult to place in the esophagus even with an external support system (n = 9) or could not be placed (n = 1), and image quality of the CHD was optimal (n = 2), adequate (n = 3), or poor (n = 5). Both probes provided images in a 1.0-kg dog. Probe limitations included lack of lateral motion (microprobe), the need for an external support system (ICE probe) and inability to consistently maintain contact with the esophagus (ICE probe).

CONCLUSION

The 10T-D microprobe provided high-quality TEE images more consistently than the ICE probe in the majority of dogs in this study; however, the lack of lateral motion can diminish its utility in some dogs.

Congenital ventricular outflow tract obstructions in Boxer dogs: Results of a 17-year cardiovascular breed screening program in France (3126 dogs)

INTRODUCTION

Ventricular outflow tract obstructions including aortic (AS) and pulmonic stenosis (PS) are the most common canine congenital heart diseases, with Boxer dogs being predominantly affected. This has led to the French Boxer club adopting a mandatory national control program against AS and PS. The objective of this retrospective study was to analyze the results of 17 years of this cardiovascular breed screening program (2005-2021).

MATERIALS AND METHODS

The records of untreated and non-anesthetized adult Boxer dogs screened between 2005 and 2021 were retrospectively reviewed. All dogs underwent physical examination and standard transthoracic echocardiography with concomitant ECG tracing. All examinations were reviewed by one single board-certified specialist in cardiology.

RESULTS

Out of the 3126 dogs screened during the study period, 3001 dogs (female:male sex ratio = 2.2, median age [IQR] = 1.6 years [1.2-2.1]) were recruited for data analysis. A total of 218 operators were involved in the screening program. For most Boxer dogs (i.e., 93.8% for AS and 94.5% for PS), a single examination was required to obtain a definitive cardiac status, although most operators were non-specialist general practitioners. A left basilar systolic heart murmur was detected in all dogs with AS and PS, but also in 7.4% dogs free of heart diseases. A significantly higher proportion of the latter was detected when operators were board-certified specialists (P<0.001). Lastly, when comparing the start and the end of the breeding program, among dogs diagnosed with AS and PS (n = 364) in a French referral cardiology center, Boxer went from the 1st affected breed by AS to the 3rd, and from the 3rd affected breed by PS to the 6th.

CONCLUSION

This 17-year screening program has experienced a strong involvement of veterinarians, breeders, and owners throughout France. This may have contributed to reduce AS and PS prevalence in Boxer dogs at the studied referral cardiology center.

Granulomatous Inflammation and Pericarditis Induced by Silk Granuloma Related to Previous Surgical Ligation of Patent Ductus Arteriosus in a Dog

Surgical ligation of a patent ductus arteriosus is regarded as a standard treatment approach with a low complication rate if performed by experienced surgeons, and it has been performed successfully for decades in dogs. However, there are no reports describing the clinical symptoms related to granulomatous inflammation after the surgical ligation of the patent ductus arteriosus. This report describes the clinical symptoms caused by granulomatous inflammation and subacute pericarditis in a dog that had undergone the surgical closure of a patent ductus arteriosus 2 years previously. Exploratory thoracotomy was performed for subtotal pericardiectomy, and a biopsy was performed to obtain specimens for histopathological examination and culture tests. The clinical symptoms were relieved after surgery. The persistent leukocytosis improved with steroid administration. This case illustrates that the granulomatous inflammatory response associated with silk suture granuloma is a rare postoperative complication of ductal ligation. In such cases, pericardiectomy can help relieve the clinical symptoms.

Congenital malformations in brachycephalic dogs: A retrospective study

The popularity of brachycephalic dogs has increased in recent years due to their docile temperament and peculiar features. The historical inbreeding and consequent lack of genetic diversity involved in the development of these breeds led to an increase in the manifestation of deleterious genes that may lead to malformations. In addition, there are serious health issues intrinsic to the conformation, mainly attributed to these extreme characteristics. Therefore, this retrospective study aimed to observe the frequency of malformations in brachycephalic dogs compared to the pure and mixed breeds (MB). The medical records of pregnant bitches admitted at the Service of Obstetrics and Animal Reproduction (SORA) from January 2017 to December 2021 were retrieved from the hospital's computer system and analyzed one by one. Seven hundred sixty-eight neonates born from 168 litters were included in this study. Of these litters, 72.6% (122/168) were brachycephalic. Malformations were found in 52 puppies, with an incidence of 6.77% (52/768). Of the 32 litters that produced malformed puppies, 28 were brachycephalic (87.5%). In total, 23 types of malformations were registered, the most common being cleft palate (1.30%) and anasarca (1.17%). Ten of the puppies (10/52; 19.23%) presented two or more associated malformations. Bitches above 7 years were more prone to present malformed puppies in their litters. Brachycephalic breeds were 3.03 times more likely to present malformed neonates when compared to other breeds; the odds ratio increased to 5.07 when modern brachycephalic was compared to ancestral brachycephalic. Regarding the mode of delivery, elective cesarean sections accounted for 66.6% of births while 19.64% were eutocic vaginal deliveries, and 13.69% were dystocic. The presence of malformed puppies in a litter causes suffering for the owner, the bitch and for the puppy itself, therefore, the veterinarian plays a key role in this scenario. Knowledge about congenital abnormalities, their causes, diagnosis, and approach is essential to reduce the incidence of malformations and improve the quality of life of these animals.

Right atrioventricular valve dysplasia in a meerkat

A 7-y-old, captive, intact female meerkat (Suricata suricatta) was presented with lethargy, decreased appetite, dyspnea, and distended abdomen. At autopsy, the right atrium was markedly dilated, and the right atrioventricular valve (RAV) was dysplastic with shortened or absent chordae tendineae and direct attachment of the valve to the papillary muscles, which, in turn, were fused and abnormally positioned. The right ventricle was considered to be hypertrophied. Also present were hydrothorax, ascites, atelectasis, and hepatic congestion. A diagnosis of RAV dysplasia was made. Histologic findings included hypertrophy of cardiomyocytes and marked centrilobular hepatic congestion and hemorrhage, which were consistent with right-sided heart failure.

Transjugular Patent Ductus Arteriosus Occlusion in Seven Dogs Using the Amplatzer Vascular Plug II

Simple Summary

This study outlines the authors’ experience using the Amplatzer Vascular Plug II device for occlusion of patent ductus arteriosus (PDA) in dogs through a right transjugular approach, never before described in veterinary medicine for this purpose. The obtained results demonstrate that the use of the Amplatzer Vascular Plug II via a transvenous right jugular approach is a feasible and effective method, even in small-sized patients. The authors’ experience is that the transvenous approach is a safe and effective method for PDA occlusion in dogs. Furthermore, the right jugular approach provides easier and faster vascular access than the femoral one. The authors affirm that this approach, together with the properties of the Amplatzer Vascular Plug II and its wide size selection, potentially provide a novel method that can complement the current available methods for transcatheter PDA occlusion.

Abstract

Although vascular plugs for the closure of patent ductus arteriosus (PDA) have been validated in dogs, studies are lacking on its use as a first-choice device with a transjugular approach. The present case series describes the transvenous right jugular embolization of PDA using an Amplatzer Vascular Plug II in seven dogs of different ages, breeds, and body weights. Complete closure of the PDA was demonstrated in all cases. All dogs showed significant hemodynamic reduction of pulmonary overcirculation and left heart size after the procedure and at following echocardiographic check-ups. Transjugular PDA occlusion using an Amplatzer Vascular Plug II can thus be considered as a safe alternative to the arterial or venous femoral approach using an Amplatzer canine ductal occluder (ACDO), particularly in puppies with small femoral vessels.

Percutaneous Balloon Dilation in Two Dogs with Cor Triatriatum Dexter

Percutaneous balloon dilation was performed in a Rhodesian Ridgeback and in an American Staffordshire Terrier affected by cor triatriatum dexter (CTD). Both cases had ascites without jugular venous distension or pleural effusion. In both dogs the CTD presented a perforated membrane but with different morphology: in one case the coronary sinus entered the caudal chamber of the CTD together with the caudal vena cava. In the other case, the coronary sinus communicated with the cranial chamber of the CTD together with the cranial vena cava. Percutaneous balloon dilation of the CTD was successfully performed, and both dogs had uneventful surgery recoveries. At two years of follow-up, the dogs were free from clinical signs and cardiac medication.

Color M-Mode Echocardiography for Non-Invasive Assessment of the Intraventricular Pressure in Dogs Before and After Ductus Arteriosus Occlusion: A Retrospective Study

Background

Novel non-invasive evaluation of the intraventricular pressure differences and gradients (IVPD and IVPG) by color M-mode echocardiography (CMME) is a promising method in diastolic function evaluation. Patent ductus arteriosus (PDA) is a congenital heart defect which is associated with increased preload. The present work provides a clinical trial for the assessment of IVPD and IVPG changes in dogs before and after surgical occlusion of PDA.

Materials and Methods

A total of 12 client-owned dogs were enrolled in this study. PDA was confirmed using echocardiography, and all dogs underwent PDA occlusion. Conventional echocardiography and CMME were conducted on each patient on the operation day (Pre-PDA) and 48 h after its occlusion (Post-PDA). The total IVPD and total IVPG, as well as segmental intraventricular pressure (basal, mid-to-apical, mid, and apical) were measured from Euler's equation using specific software (MATLAB). Data were analyzed for variability and for the difference between pre- and post-PDA. The effect of PDA occlusion on the measured variables was calculated using biserial ranked correlation (rc).

Results

There was a significant reduction in end-diastolic volume, fraction shortening, stroke volume, and mitral inflow velocities (early and late) after PDA closure. CMME was feasible in all dogs, and the CMME indices showed moderate variability, except for the apical segment of IVPD and IVPG. After PDA closure, in comparison with the pre-PDA occlusion, there was a significant reduction in total IVPD (2.285 ± 0.374 vs. 1.748 ± 0.436 mmHg; P = 0.014), basal IVPD (1.177 ± 0.538 vs. 0.696 ± 0.144 mmHg; P = 0.012), total IVPG (1.141 ± 0.246 vs. 0.933 ± 0.208 mmHg; P = 0.032), and basal IVPG (0.578 ± 0.199 vs. 0.377 ± 0.113 mmHg; P = 0.001); meanwhile, mid, mid-to-apical, and apical segments of both IVPD and IVPG showed non-significant difference. The magnitude of PDA occlusion on the measured variables was clinically relevant and associated with a large effect size on total and basal IVPD and IVPG (rc > 0.6).

Conclusion

The current clinical study revealed matched response of IVPD and IVPG to the reduced preload rather than left ventricular relaxation. This result is an initial step in the clinical utility of CMME-derived IVPD and IVPG measurements in the diastolic function evaluation in dogs with PDA that warrants further clinical studies.

Effect of preoperative administration of atenolol to dogs with pulmonic stenosis undergoing interventional procedures

Background

Beta‐blockade is sometimes used in dogs with pulmonic stenosis with the intent of reducing frequency of ventricular arrhythmias during right heart catheterization.

Objectives

To evaluate if pretreatment with atenolol reduces frequency of ventricular arrhythmias, anesthetist interventions, or shortens procedure time.

Animals

Thirty dogs with pulmonic stenosis scheduled for interventional procedures.

Methods

Single center, prospective, randomized, open‐label study. Dogs were randomized to treatment with atenolol or no treatment preoperatively for a minimum of 10 days. Variables recorded included heart rate, arrhythmias and complexity, total procedure time and administration of antiarrhythmic treatment, vasopressors, positive chronotropes, or fluid boluses.

Results

Fifteen dogs were enrolled in each group. Dogs receiving atenolol had lower mean heart rates during the procedure (atenolol 100 ± 11 bpm vs untreated 115 ± 19 bpm, P = .01). There were no significant differences between the atenolol and untreated groups in the frequency of ventricular ectopic complexes (535 [6‐5296] vs 553 [79‐2863], P = .9), ventricular couplets (46 [0‐481] vs 29 [3‐121], P = .59), ventricular triplets (20 [0‐265] vs 16 [1‐82], P = .67), ventricular tachycardia (8 [0‐224] vs 8 [1‐118], P = .99), proportion exhibiting R‐on‐T phenomenon (11/15 vs 14/15, P = .33), proportion receiving intraoperative lidocaine (1/15 vs 3/15, P = .6), vasopressors/positive chronotropes (11/15 vs 5/15, P = .06), or fluid boluses (12/15 vs 7/15, P = .13). The procedure time was similar (atenolol 41 [23‐68] min vs untreated 35 [18‐98] min, P = .91).

Conclusions and Clinical Importance

No benefit of preoperative atenolol treatment was identified in this small group of dogs.

Surgical ligation of patent ductus arteriosus in dogs: Incidence and risk factors for rupture

OBJECTIVE

To determine the rates of rupture and mortality associated with surgical ligation of patent ductus arteriosus (PDA) in dogs and to identify risk factors for rupture.

STUDY DESIGN

Retrospective cohort.

ANIMALS

Two-hundred and eighty-five dogs with PDA undergoing surgical ligation.

METHODS

Information regarding signalment, weight, surgical findings, complications, presence of residual flow, and survival was recorded. Age, weight, and presence of residual flow were compared between cases with and without rupture.

RESULTS

The initial surgical approach was extrapericardial (144), intrapericardial (46), not reported (94), or Jackson-Henderson (1). Rupture of the PDA occurred in 7.0% of dogs (20/285, 13 extrapericardial, 3 intrapericardial, 4 not reported). No difference in age or weight was found between dogs with and without rupture. Overall mortality was 0.4% (1/285). Additional major complications occurred in 1.4% of dogs, all in the nonrupture group. The overall rate of residual flow after ligation was 9.4%. Dogs with rupture were more likely to have residual flow than those without rupture (P = .012). If ligation was performed after rupture (rather than hemostasis only), no difference in residual flow rates (P = .398) was noted between dogs with rupture and those without.

CONCLUSION

The rate of rupture with surgical ligation of PDAs was low. No specific risk factors for rupture were identified.

CLINICAL SIGNIFICANCE

Successful treatment of PDA rupture is possible, evidenced by the low mortality rate in this population of dogs. Ligation of the PDA after rupture, either in the concurrent or a subsequent procedure, reduces the odds of residual flow.

Clinical and Electrocardiographic Findings for Predicting the Severity of Pulmonary Valve Stenosis in Dogs

Pulmonary valve stenosis (PS) in dogs is usually suspected due to the presence of a heart murmur and clinical signs. Echocardiography is needed to confirm the diagnosis and define the severity of PS. This retrospective study evaluated the utility of clinical and electrocardiographic (ECG) findings in the prediction of PS severity. Data regarding heart murmur and ECG analysis were gathered. Ninety-seven dogs with PS were included. A murmur grade ≥IV/VI was predictive of severe PS (area under curve (AUC) = 0.71; sensitivity (Se) = 95%; specificity (Sp) = 33%; p = 0.003). In lead II, P wave amplitude >0.35 mV (AUC = 0.67; Se = 31%; Sp = 100%; p = 0.038), Q wave < 0.15 mV (AUC = 0.70; Se = 70%; Sp = 59%; p = 0.0015), R wave < 0.87 mV (AUC = 0.66; Se = 67%; Sp = 69%; p = 0.006), and S wave > 0.37 mV (AUC = 0.80; Se = 72%; Sp = 85%; p < 0.0001) were predictive of severe PS. The extent of right deviation of the mean electrical axis of the QRS complex was correlated with the pulmonary pressure gradient (r = 0.648; p < 0.0001). In conclusion, a systolic murmur with intensity ≥IV/VI, a P wave amplitude >0.35 mV, low amplitude of Q and R waves, deep S waves in lead II, and right axis deviation of the QRS complex in a young dog are predictive of severe PS.