Trypanosoma cruzi infection diagnosed in dogs in nonendemic areas and results from a survey suggest a need for increased Chagas disease awareness in North America.

OBJECTIVE: To describe the clinical presentation and outcome in dogs diagnosed with Trypanosoma cruzi infection in nonendemic areas and to survey veterinary cardiologists in North America for Chagas disease awareness. ANIMALS: 12 client-owned dogs; 83 respondents from a veterinary cardiology listserv. PROCEDURES: A retrospective, multicenter medical records review to identify dogs diagnosed with American trypanosomiasis between December 2010 and December 2020. An anonymous online survey was conducted August 9 to 22, 2022. RESULTS: Diagnosis was made using indirect fluorescent antibody titer (n = 9), quantitative PCR assay (1), or postmortem histopathology (2). Time spent in Texas was < 1 year (n = 7) or 2 to 8 years (5). Time in nonendemic areas prior to diagnosis was < 1 year (n = 10) and > 3 years (2). Eleven had cardiac abnormalities. Of the 12 dogs, 5 had died unexpectedly (range, 1 to 108 days after diagnosis), 4 were still alive at last follow-up (range, 60 to 369 days after diagnosis), 2 were euthanized because of heart disease (1 and 98 days after diagnosis), and 1 was lost to follow-up. Survey results were obtained from 83 cardiologists in North America, of which the self-reported knowledge about Chagas disease was limited in 49% (41/83) and 69% (57/83) expressed interest in learning resources. CLINICAL RELEVANCE: Results highlight the potential for encountering dogs with T cruzi infection in nonendemic areas and need for raising awareness about Chagas disease in North America.

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

Multi-centered investigation of a point-of-care NT-proBNP ELISA assay to detect moderate to severe occult (pre-clinical) feline heart disease in cats referred for cardiac evaluation.

OBJECTIVE: To prospectively evaluate the diagnostic accuracy of a point-of-care (POC) N-terminal pro-B-type natriuretic peptide (NT-proBNP) ELISA to assess the likelihood of moderate to severe occult heart disease (OcHD) in a clinical population of cats suspected to have heart disease. ANIMALS: One hundred and forty-six asymptomatic client-owned cats with a heart murmur, gallop rhythm, arrhythmia, or cardiomegaly. METHODS: Physical examination, blood pressure measurement and echocardiography were performed prospectively. Point-of-care ELISA was visually assessed as either positive or negative by a reader blinded to the echocardiographic results. RESULTS: Forty-three healthy cats, 50 mild OcHD, 31 moderate OcHD, 6 severe OcHD, and 16 cats equivocal for OcHD were examined. Cats with OcHD included 65 with hypertrophic cardiomyopathy, 6 with restrictive or unclassified cardiomyopathy, 1 with arrhythmogenic right ventricular cardiomyopathy, and 15 with non-cardiomyopathic forms of heart disease. Point-of-care ELISA differentiated cats with moderate or severe OcHD with sensitivity/specificity of 83.8%/82.6% and overall accuracy of 82.9%. Positive POC ELISA increased likelihood of moderate or severe OcHD by a factor of 4.8 vs. those that tested negative. Point-of-care ELISA differentiated cats with moderate or severe cardiomyopathic OcHD with sensitivity/specificity of 88.6%/81.3% and overall accuracy of 83.2%. CONCLUSION: In a select sample of cats referred for cardiac evaluation, positive POC NT-proBNP ELISA increases likelihood of moderate to severe OcHD while negative POC NT-proBNP ELISA result excludes moderate to severe OcHD.

Effect of oral administration of pimobendan in cats with heart failure.

OBJECTIVE: To determine the effect of PO administration of pimobendan on clinical and echocardiographic variables and survival time in cats with heart failure characterized by ventricular systolic dysfunction. DESIGN: Retrospective cohort study. ANIMALS: 27 client-owned cats (16 male and 11 female) with heart failure, treated with pimobendan (mean ± SD dosage, 0.26 ± 0.08 mg/kg [0.118 ± 0.036 mg/lb], PO, q 12 h). PROCEDURES: Information on medical history, laboratory results, diagnostic imaging findings, treatments received, and survival time were obtained from medical records of cats that received pimobendan because of cardiac disease. When possible, additional follow-up information was obtained through telephone interviews with referring veterinarians and owners. RESULTS: The mean ± SD age of all 27 cats was 8.9 ± 5.2 years. All cats had received several cardiac medications. Types of heart disease represented included unclassified cardiomyopathy (CM; n = 11 [41%]), dilated CM (8 [30%]), arrhythmogenic right ventricular CM (4 [15%]), congenital heart disease (3 [11 %]), and hypertrophic CM with regional hypokinesis (1 [4%]). All cats had ventricular systolic dysfunction. One cat with systolic anterior motion of the mitral valve became severely hypotensive after initial administration of pimobendan and was excluded from the survival analysis. Median survival time was 167 days (95% confidence interval, 32 to 339 days). CONCLUSIONS AND CLINICAL RELEVANCE: Pimobendan appeared to be well tolerated in cats with heart failure characterized by ventricular systolic dysfunction of various etiologies. Cats with systolic anterior motion of the mitral valve may develop systemic hypotension when treated with pimobendan. Additional studies are needed to establish dosages for pimobendan and its effects before it can be recommended for treatment of cats with CHF.

Transarterial ductal occlusion using the Amplatz Canine Duct Occluder in 40 dogs.

OBJECTIVES: Describe the result of patent ductus arteriosus (PDA) occlusion using the Amplatz Canine Duct Occluder (ACDO) in 40 dogs. ANIMALS, MATERIAL AND METHODS: Records of the first 41 dogs at Texas A&M University in which ductal occlusion with an ACDO was attempted were reviewed. RESULTS: Appropriate device release was achieved in 40 of 41 dogs. Post-release angiography in 39 dogs documented complete occlusion in 27 dogs, trivial residual flow in 7, mild residual flow in 1 and moderate residual flow in 4; angiography was not recorded in one dog. The following day transthoracic color Doppler echocardiography documented complete occlusion in all 40 dogs. One dog required a larger device than could be deployed through the largest sheath accommodated by the femoral artery and the PDA was subsequently closed by surgical ligation. CONCLUSIONS: Ductal occlusion using an ACDO has a high rate of initial and 24-h complete occlusion. Ductal occlusion using an ACDO is a safe and efficacious therapy for PDA in dogs. This report confirms the positive clinical outcome of the original report in a large cohort of dogs.

Open heart closure of an atrial septal defect by use of an atrial septal occluder in a dog.

CASE DESCRIPTION: A 3-year-old sexually intact male Standard Poodle was admitted to the veterinary teaching hospital for transcatheter closure of a large atrial septal defect (ASD). CLINICAL FINDINGS: The dog had exercise intolerance and was thin. Findings on physical examination were within normal limits with the exception of a left base systolic heart murmur (grade 5/6). The dog was not receiving any medications. Echocardiography and thoracic radiography confirmed the diagnosis of ASD and revealed compensatory changes consistent with a large left to right shunting ASD. Results of serum biochemical analysis and CBC were within reference range limits. TREATMENT AND OUTCOME: Transcatheter ASD closure with an atrial septal occluder (ASO) was performed and failed. An open heart surgical approach under cardiopulmonary bypass was declined by the dog's owners. The dog underwent a novel hybrid approach involving active device fixation under temporary inflow occlusion after transatrial device deployment. The dog recovered with some manageable postoperative complications. As of the last follow-up examination, the dog had 10 months of event-free survival. CLINICAL RELEVANCE: Transcatheter closure by use of an ASO and open heart patch repair with cardiopulmonary bypass to surgically treat dogs with ASD has been reported. Transcatheter closure is not possible in dogs with large ASD. The novel hybrid procedure reported herein represented a viable alternative to euthanasia.

Outcome of minimally invasive surgical treatment of heartworm caval syndrome in dogs: 42 cases (1999-2007).

OBJECTIVE: To report the outcome of minimally invasive surgical treatment of heartworm caval syndrome in a series of dogs and to provide information on long-term survival of patients with this condition. DESIGN: Retrospective case series. ANIMALS: 42 client-owned dogs with a diagnosis of heartworm caval syndrome. PROCEDURES: Information on history, clinical, laboratory, and diagnostic imaging findings and treatment was obtained from medical records. When possible, additional follow-up information was obtained through telephone interviews with referring veterinarians and owners. RESULTS: Of the 42 dogs with caval syndrome, 21 underwent minimally invasive surgical treatment consisting of transvenous heartworm extraction. Two of the 21 dogs died during the procedure, and after surgery, 4 died. Following induction of anesthesia, heartworms migrated into the distal portion of the pulmonary artery in 1 dog; therefore, extraction was not attempted. Transvenous heartworm extraction was completed successfully in 14 dogs, and all 14 of these dogs were discharged from the hospital. Mean follow-up time in these 14 dogs was 24.4 +/- 17.7 months with a range of 2 to 56 months. At the time of final follow-up, 10 of these 14 dogs had survived at least 18 months and 7 had survived > 24 months. By the end of the study, 1 dog was lost to follow-up and 3 had been euthanatized for unrelated reasons. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the study reported here suggest that dogs with caval syndrome that undergo successful transvenous heartworm extraction and survive to discharge have a good long-term prognosis.

Late cardiac perforation by a passive-fixation permanent pacemaker lead in a dog.

CASE DESCRIPTION: A 12-year-old Miniature Dachshund with a history of permanent endocardial pacemaker implantation performed 7 weeks previously was admitted for routine dental prophylaxis. CLINICAL FINDINGS: Preanesthetic ECG revealed normal ventricular capture. Thoracic radiographic findings included caudomedial displacement of the endocardial pacemaker lead. Echocardiography revealed moderate chronic degenerative valve disease with moderate left atrial and ventricular dilation. After induction of anesthesia, loss of ventricular capture was detected. The dog recovered from anesthesia and had improved ventricular capture. The following day, surgical exposure of the cardiac apex revealed perforation of the right ventricular apex by the passive-fixation pacemaker lead. TREATMENT AND OUTCOME: A permanent epicardial pacemaker was implanted through a transxiphoid approach. Appropriate ventricular capture and sensing were achieved. The dog recovered without complications. Approximately 2 months later, the dog developed sudden respiratory distress at home and was euthanized. CLINICAL RELEVANCE: In dogs with permanent pacemakers and loss of ventricular capture, differential diagnoses should include cardiac perforation. If evidence of perforation of the pacemaker lead is found, replacement of the endocardial pacemaker lead with an epicardial pacemaker lead is warranted.