Non-cardiogenic pulmonary oedema complicating balloon valvuloplasty and stent angioplasty of severe pulmonary valve stenosis in four dogs.

In dogs, balloon valvuloplasty is considered the treatment of choice for severe pulmonary valve stenosis, and this technique is currently performed routinely in specialist referral practices with low morbidity and mortality. Stent angioplasty has also been recently proposed as a viable treatment option. The present case series describes the clinical course of four dogs with severe pulmonary valve stenosis, treated with balloon valvuloplasty or stent angioplasty at four different institutions, which developed non-cardiogenic pulmonary oedema perioperatively after apparently successful dilation of the pulmonary valve. In three cases, there was evidence of some degree of pulmonary hypertension before ballooning. Despite intensive care, the complication proved fatal in three cases. Clinicians should therefore be aware of this life-threatening complication, previously undescribed in dogs.

Holter monitoring in dogs: 24 h vs. 48 h.

Holter monitoring has an important role in the diagnosis of cardiac arrhythmias in dogs with underlying heart disease or clinical signs such as intermittent weakness/ collapse or exercise intolerance, and in the assessment of antiarrhythmic treatment efficacy. A typical recording lasts for 24 h, although 48 h or any number of days up to 7 are possible, especially when investigating clinical signs that may not happen during the first 24 h. The objective of this study was to review retrospectively a large number of 48 h Holter recordings obtained from dogs to assess the possible incremental diagnostic yield of the second 24 h period in comparison to the first 24 h. Three hundred and fifty four 48 h Holter recordings were included in the study for analysis. A 48 h Holter recording contributed to a 14.5% increase in the likelihood of documenting the cardiac rhythm during an event of interest; a 24 h recording increased the diagnostic yield from 32.2% to 46.7%. When the recordings were grouped according to the most important rhythm abnormalities (supraventricular arrhythmias group, ventricular arrhythmias group, bradyarrhythmias group, no arrhythmias group), the 48 h Holter monitor contributed to a 5% increase in the likelihood of identifying a relevant cardiac rhythm abnormality, increasing the diagnostic yield from 58% to 63%. This benefit occurred mostly in dogs with iterative or paroxysmal supraventricular arrhythmias. In dogs with bradyarrhythmias or ventricular arrhythmias, an additional 24 h of analysis was useful in only a limited number of cases.

Heart rhythm during episodes of collapse in boxers with frequent or complex ventricular ectopy.

OBJECTIVES: To describe heart rhythm during collapse events in boxer dogs using ambulatory electrocardiogram and determine the predictive value of frequent or complex ventricular ectopy for collapse associated with ventricular tachycardia. MATERIALS AND METHODS: A total of 659 ambulatory electrocardiogram recordings from 429 boxer dogs were identified from a database in the UK. Summary statistics described the frequency and complexity of ventricular ectopy during all recordings, recordings in which collapse occurred and associated boxer demographics. Positive predictive values were calculated to investigate whether frequent ventricular ectopy was useful to predict heart rhythm during episodes of collapse. RESULTS: Of the 659 ambulatory electrocardiogram recordings, 250 recordings showed <50 single ventricular beats (Group 1), and frequent (≥50) or complex ventricular ectopy were observed in 409 recordings (Group 2). A total of 90 collapse events were observed in 72 ambulatory electrocardiograms from 68 dogs, comprising 30 dogs in Group 1 and 38 dogs in Group 2. In both groups, sinus rhythm was the most frequent collapse rhythm, followed by neurally mediated collapse and then ventricular tachycardia. The proportion of dogs that displayed ventricular tachycardia-associated episodic collapse given that they had frequent (≥50) or complex ventricular ectopy in the study population was 0.11 [95% confidence interval = 0.01 to 0.21]. CLINICAL SIGNIFICANCE: These results challenge the preconception that UK boxer dogs with collapse will have ventricular tachycardia and, consequently, the authors recommend definitive diagnosis of the cause of episodic collapse to guide selection of therapeutic drugs.

Cytokine expression in peripheral blood mononuclear cells of dogs with mitral valve disease.

Inflammation plays an important role in the pathogenesis of congestive heart failure (CHF). In humans with CHF, increased production and high plasma concentrations of tumour necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1, IL-8 and transforming growth factor-ß (TGF-ß) have been associated with disease progression and a negative prognosis. The aim of this study was to investigate whether differences in cytokine blood mRNA expression exist between clinically healthy dogs and dogs with myxomatous mitral valve disease (MMVD); to determine if the expression was related to the severity of MMVD, and to detect any correlations with echocardiographic parameters of cardiac remodelling. Twenty-three dogs with MMVD of varying severity and six clinically healthy dogs were included in the study. Whole blood samples were obtained for measurement of mRNA expression of IL-1α, IL-1ß, IL-6, IL-8, TGF-ß1, TNF-α by reverse transcriptase-PCR (RT-PCR). There were statistically significant differences between clinically healthy dogs and dogs with MMVD for IL-8 and TGF-ß1 gene expression. IL-8 expression increased with increasing MMVD severity and TGF-ß1 expression was higher in asymptomatic dogs with echocardiographic signs of cardiac remodelling (American College Veterinary Internal Medicine class B2) than in all other groups. These results could suggest the involvement of these cytokines at different stages of the disease.

Transesophageal echocardiography guided patent ductus arteriosus occlusion with a duct occluder.

BACKGROUND: Angiography and fluoroscopy are the standard methods to guide transcatheter occlusion of patent ductus arteriosus (PDA). The use of iodinated contrast agents and radiation exposure pose risks of animals and staff. OBJECTIVES: To assess feasibility of transesophageal echocardiography (TEE) for device size selection and procedure monitoring for PDA occlusion with a duct occluder (DO) without the use of angiography. ANIMALS: Eighty client-owned dogs with left-to-right PDA. METHODS: Prospective study. Dogs with left-to-right PDA undergoing transcatheter occlusion were included. Procedures were performed without angiography and device size selection was based on TEE measurements. Procedures were monitored with simultaneous TEE and fluoroscopy and both methods were compared. Visualization of the ductus and dimensions obtained by TEE and transthoracic echocardiography (TTE) were compared. RESULTS: Complete PDA occlusion was achieved in 79/80 cases. TEE was consistently superior to TTE for PDA visualization and the latter showed higher values for ductal dimensions when compared to the former. TEE provided adequate procedure monitoring in 73 cases (91%). Fluoroscopy exposure time (2.77 ± 1.2 minutes (mean, SD)) was lower than previously reported for the same procedure. CONCLUSIONS AND CLINICAL IMPORTANCE: TEE is a useful and efficient tool for device size selection and can be used for procedure monitoring in most cases. Fluoroscopy exposure time can be reduced and the use of contrast agents can be avoided. However, fluoroscopy is required in a minority of cases when TEE monitoring is not feasible or incomplete and should be available for this procedure.

Disseminated histoplasmosis in a cat in Europe.

A cat was presented with a history of vomiting, decreased appetite and weight loss. Abnormal findings were poor body condition, pale mucous membranes, dehydration and a palpable abdominal mass. Abdominal ultrasound showed lymph node enlargement, a mass of uncertain origin, thickening of the muscularis layer of the small bowel, focal thickening of the ileum with loss of layering and free peritoneal fluid. Cytology revealed a piogranulomatous infiltrate and numerous macrophages containing oval or round yeast-like cells 2 to 5 microm diameter with a central, spherical, lightly basophilic body surrounded by a clear halo, compatible with Histoplasma capsulatum, within the cytoplasm. Post-mortem examination revealed cavity effusions, granulomatous nodules in lungs, intestine and omentum, thickened intestinal walls and intestinal perforation. Staining with Grocott and immunohistochemistry (IHC) revealed numerous organisms within the granulomatous reaction. H. capsulatum has a worldwide distribution in temperate and subtropical climates. To the author's knowledge, this is the first report of feline histoplasmosis in Europe.

A combination of doxycycline and ivermectin is adulticidal in dogs with naturally acquired heartworm disease (Dirofilaria immitis).

Canine heartworm disease is caused by infection with Dirofilaria immitis, a filarial nematode that resides in the pulmonary arteries and occasionally in the right heart chambers of infected dogs. Here the authors evaluated the effect of a combination of doxycycline (10 mg/kg/sid for 30 days) and ivermectin­pyrantel(6µg/kg [DOSAGE ERROR CORRECTED] of ivermectin+5mg/kg of pyrantel every 15 days for 180 days) on microfilariemia, antigenemia and parasite load at echocardiography in naturally infected dogs from an endemic region of Italy. Dogs were examined monthly for 6 months and followed-up 4 months later. One hundred percent of dogs became negative for circulating microfilariae by day 90, while 8/11 (72.7%) of dogs became antigen-negative by day 300. Of the 7 dogs that were positive for visualization of parasites at echocardiography, 6 (85.7%) became negative by day 300. Treatment was well-tolerated by all dogs. These results suggest that a combination of doxycycline and ivermectin is adulticide in dogs with D. immitis.

Aortic endocarditis associated with a perforated septal membranous aneurysm in a boxer dog.

Perimembranous ventricular septal defect is a common congenital heart disease in the dog. It can partially or completely close with age by development of a membranous ventricular septal aneurysm. Aortic endocarditis is a reported complication of ventricular septal defect and membranous ventricular septal aneurysm in human beings. This report describes a case of aortic endocarditis associated with a membranous ventricular septal aneurysm perforated by a small ventricular septal defect in a boxer dog.

Late failure and revisions of old-type total knee replacements.

This paper reports the failure rate and survival of old-generation total knee replacements (TKR). Revision operations are also discussed. During a 5-year period from 1974 to 1979, 117 patients, 165 knees, were operated. The prostheses used were Geomedic in 75 knees and Attenborough in 90 knees. Revision was performed in 46 knees (28%). Six knees (4%) were infected. The survival time from implantation averaged 4.3 years, and the followup was 7 to 13 years for the Geomedic (mean 9.7) and 6 to 9 years for the Attenborough (mean 6.7). Mechanical problems were related to loosening of the tibial and femoral components, and revision was required for this reason. The success rate of the revision was 50% at 5.4 years; the less invasive the primary operation, the simpler the revision. Constrained prostheses must be used when ligaments are not intact. In case of infection, removal of the implants is not always necessary.