Virginia Luis Fuentes

Chronic pulmonary disease in West Highland white terriers

This paper describes the clinical features, and diagnostic findings of a chronic respiratory condition in 29 West Highland white terriers. Typically, the dogs were coughing chronically, had dyspnoea and tachypnoea of varying severity, and had deteriorated progressively over months to year. The mean (sem) survival time in months from the clinical signs being first noted by the owners was 17.9 (2.3). Most cases had a combination of respiratory signs, but coughing was the predominant sign in 18 cases. Inspiratory crackles were audible on chest auscultation in 28 cases, 10 of which were also wheezing. Rhonchi were the predominant sound in the remaining case. The main radiographic changes were mild to severe increased interstitial markings in all cases, with additional bronchial markings in 14 of the dogs. Right-sided cardiomegaly (cor pulmonale) was recorded in 15. Bronchoscopic findings in 17 of the dogs were either normal or involved a mild airway mucoid reaction in eight. Chronic mucosal changes were observed in eight, but in two this finding was equivocal. Dynamic changes to the lumen of the airway were present in seven cases. No significant haematological or biochemical changes could be detected in 20 cases, but four cases were hypercholestrolaemic. A histopathological assessment of four cases revealed alveolar septal fibrosis to be the predominant change. Prednisolone, with or without bronchodilators, was the most commonly used therapy, and the response was variable. The condition appears to be associated with significant pulmonary interstitial fibrosis of unknown aetiology and has clinical similarities to idiopathic pulmonary fibrosis (cryptogenic fibrosing alveolitis) in human beings.

Comparison of auscultatory and echocardiographic findings in healthy adult cats.

OBJECTIVES This pilot study was performed to investigate murmur prevalence and to explore the association between auscultatory and echocardiographic findings in apparently healthy cats in order to design a larger study. ANIMALS, MATERIALS AND METHODS Adult cats in 4 rehoming centres were screened by auscultation and echocardiography (echo) over 2 periods of 2 weeks each. In the first period, echo was attempted only in cats with murmurs. In the second period, all cats underwent auscultation by 2 observers and echo. LVH was defined in 5 ways: maximal diastolic left ventricular (LV) wall thickness ≥ 6 mm or ≥ 5.5 mm with 2D (LVH(6 2D), LVH(5.5 2D), respectively) or M-Mode echo (LVH(6 MM) or LVH(5.5 MM) respectively), or LV wall thickness ≥ 6 mm (2D) for >50% of a wall segment (LVH(50%)). RESULTS 67/199 (34%) cats had a murmur. Interobserver agreement on murmur presence was moderate (κ 0.47). 61 cats with a murmur and 31 cats without underwent both auscultation and echo. Depending on the criteria, LVH was present in 31 (LVH(6 2D)), 21 (LVH(50%)) and 11 (LVH(6 MM)) scanned cats. 18-62% of cats with murmurs had LVH, depending on the echo criteria used. Agreement was best between observers in identifying LVH using LVH(6 2D) and LVH(50%) (κ = 1.0). CONCLUSIONS Heart murmurs are common in apparently healthy cats. The prevalence of LVH varies depending on the criteria used.

Cardiomyopathy prevalence in 780 apparently healthy cats in rehoming centres (the CatScan study)

OBJECTIVES Hypertrophic cardiomyopathy (HCM) appears to be common in cats and, based on pilot data, a prevalence of 15% has been hypothesized. The objectives were to screen a large population of apparently healthy adult cats for cardiac disease, and identify factors associated with a diagnosis of HCM. ANIMALS A total of 1007 apparently healthy cats ≥ 6 months of age. METHODS In this prospective, cross-sectional study, the inclusion criteria were: apparently healthy cats, aged ≥ 6 months, available for rehoming over a 17-month period from two rehoming centres. Hypertensive or hyperthyroid cats were excluded. Body weight, body condition score, auscultation, systolic blood pressure and two-dimensional (2-D) echocardiography were evaluated. Cats with left ventricular end-diastolic wall thickness ≥ 6 mm on 2-D echocardiography were considered to have HCM. RESULTS Complete data were obtained in 780 cats. Heart murmur prevalence was 40.8% (95% confidence interval (CI) 37.3-44.3%), 70.4% of which were considered functional. The prevalence of HCM was 14.7% (95% CI 12.3-17.4%), congenital disease 0.5% (95% CI 0.1-1.3%), and other cardiomyopathies 0.1% (95% CI 0.0-0.7%). The HCM prevalence increased with age. The positive predictive value of a heart murmur for indicating HCM was 17.9-42.6% (higher in old cats), and the negative predictive value was 90.2-100% (higher in young cats). The factors associated with a diagnosis of HCM in binary logistic regression models were male sex, increased age, increased body condition score and a heart murmur (particularly grade III/VI or louder). CONCLUSIONS Hypertrophic cardiomyopathy is common in apparently healthy cats, in contrast with other cardiomyopathies. Heart murmurs are also common, and are often functional.

Arterial Thromboembolism Risks, realities and a rational first-line approach

Practical relevance: Feline arterial thromboembolism (ATE) is a common but devastating complication of myocardial disease, often necessitating euthanasia. A combination of endothelial dysfunction and blood stasis in the left atrium leads to local platelet activation and thrombus formation. Embolisation of the thrombus results in severe ischaemia of the affected vascular bed. With the classic ‘saddle thrombus’ presentation of thrombus in the terminal aorta, the diagnosis can usually be made by physical examination. The prognosis is poor for cats with multiple limbs affected by severe ischaemia, but much better where only one limb is affected or motor function is present. Patient group: Cats with left atrial enlargement secondary to cardiomyopathy are typically predisposed, although cats with hyperthyroidism, pulmonary neoplasia and supravalvular mitral stenosis may also be at risk. Management: Analgesia is the main priority, and severe pain should be managed with methadone or a fentanyl constant rate infusion. Congestive heart failure (CHF) requires treatment with furosemide, but tachypnoea due to pain can mimic signs of CHF. Thrombolytic therapy is not recommended, but antithrombotic treatment should be started as soon as possible. Aspirin and clopidogrel are well tolerated. Evidence base: Several observational studies of ATE have been reported. No randomised, blinded, controlled studies have been reported in cats at risk, for either treatment or prevention of ATE, although such a study comparing aspirin and clopidogrel in cats is currently under way.

Effect of treatment with atenolol on 5-year survival in cats with preclinical (asymptomatic) hypertrophic cardiomyopathy.

OBJECTIVES To investigate the effect of treatment with atenolol on 5-year survival in cats with preclinical hypertrophic cardiomyopathy (HCM). ANIMALS 63 Client-owned cats with preclinical HCM and 31 healthy control cats. METHODS Prospective, observational, open-label, clinical cohort study. Cats with HCM were diagnosed by echocardiography, treated with atenolol (6.25-12.5 mg q12h, PO; n = 42) or untreated (n = 21), and were observed for 5 years after enrollment. The study end point was death from any cause. Cats of similar body weight, age, gender, and breed without evidence of heart disease were studied concurrently and served as controls. RESULTS During the observational period, 27 cats with HCM died; 14 (22%) due to cardiac disease and 13 (21%) due to non-cardiac disease. Ten control cats (32%) died of non-cardiac disease. There was no significant difference (P = 0.307) in all-cause mortality between control and HCM. Cardiac mortality was higher in cats with HCM compared to control cats (P = 0.005). There was no significant difference in all-cause mortality (P = 0.729) and cardiac mortality (P = 0.897) between cats with HCM treated or untreated with atenolol. Age and left atrial size at diagnosis were the only predictors of 5-year outcome. CONCLUSIONS Our study failed to demonstrate an effect of atenolol on 5-year survival in cats with preclinical HCM.

Effects of sedation on echocardiographic variables of left atrial and left ventricular function in healthy cats

Although sedation is frequently used to facilitate patient compliance in feline echocardiography, the effects of sedative drugs on echocardiographic variables have been poorly documented. This study investigated the effects of two sedation protocols on echocardiographic indices in healthy cats, with special emphasis on the assessment of left atrial size and function, as well as left ventricular diastolic performance. Seven cats underwent echocardiography (transthoracic two-dimensional, spectral Doppler, color flow Doppler and tissue Doppler imaging) before and after sedation with both acepromazine (0.1 mg/kg IM) and butorphanol (0.25 mg/kg IM), or acepromazine (0.1 mg/kg IM), butorphanol (0.25 mg/kg IM) and ketamine (1.5 mg/kg IV). Heart rate increased significantly following acepromazine/butorphanol/ketamine (mean ± SD of increase, 40 ± 26 beats/min) and non-invasive systolic blood pressure decreased significantly following acepromazine/butorphanol (mean ± SD of decrease, 12 ± 19 mmHg). The majority of echocardiographic variables were not significantly different after sedation compared with baseline values. Both sedation protocols resulted in mildly decreased left ventricular end-diastolic dimension and mildly increased left ventricular end-diastolic wall thickness. This study therefore failed to demonstrate clinically meaningful effects of these sedation protocols on echocardiographic measurements, suggesting that sedation with acepromazine, butorphanol and/or ketamine can be used to facilitate echocardiography in healthy cats.

Arterial Thromboembolism in 250 Cats in General Practice: 2004–2012

Background Population characteristics and outcome of cats with arterial thromboembolism (ATE) managed in general practice (GP) have been poorly described. Hypothesis Cats with ATE presenting to GP are usually euthanized at presentation, but survival times >1 year are possible. Animals Cats with ATE managed by 3 GP clinics in the United Kingdom. Methods Records of cases presenting to GP over a 98‐month period (2004–2012) were reviewed. Cats with an antemortem diagnosis of limb ATE were included. Outcome information was obtained. Results Over 98 months, 250 cats were identified with ATE. Prevalence was approximately 0.3%. At presentation, 153 cats (61.2%) were euthanized, with 68/97 (70.1%) of the remaining cats (27.2% of the total population) surviving >24 hours after presentation. Of these, 30/68 (44.1%) survived for at least 7 days. Hypothermia (HR, 1.44; 95% CI, 1.002–2.07; P = .049) and management by Clinic 2 (HR, 5.53; 95% CI, 1.23–24.8; P = .026) were independent predictors of 24‐hour euthanasia or death. For cats surviving >24 hours, hypothermia (HR, 2.25; 95% CI, 1.12–4.48; P = .021) and failure to receive aspirin, clopidogrel, or both (HR, 8.26; 95% CI, 1.39–50; P = .001) were independent predictors of euthanasia or death within 7 days. For cats that survived ≥7 days, median survival time was 94 (95% CI, 42–164) days, with 6 cats alive 1 year after presentation. Conclusions Although 153/250 cats were euthanized at presentation, 6 cats survived >12 months. No factors were identified that predicted euthanasia on presentation.

Screening for hypertrophic cardiomyopathy in cats.

Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats, and it can lead to increased morbidity and mortality. Cats are often screened for HCM because of the presence of a heart murmur, but screening for breeding purposes has also become common. These cats are usually purebred cats of breeding age, and generally do not present with severe disease or with any clinical signs. This type of screening is particularly challenging because mild disease may be difficult to differentiate from a normal phenotype, and the margin for error is small, with potentially major consequences for the breeder. This article reviews HCM screening methods, with particular emphasis on echocardiography.

Doppler echocardiographic assessment of left ventricular diastolic function in 74 boxer dogs with aortic stenosis

OBJECTIVE To evaluate left ventricular (LV) diastolic function in boxer dogs with aortic stenosis (AS). BACKGROUND LV relaxation, elastic recoil, filling and stiffness have been found to be abnormal in people with AS and were related to disease severity, clinical signs and prognosis. METHODS 2-D, M-mode and Doppler echocardiography was done in 74 boxers with AS (55 with mild AS, 7 with moderate AS and 12 with severe AS) and compared with reference values from 66 normal boxers. Measurements included isovolumic relaxation time (IVRT), peak early (E) and late (A) transmitral filling velocities, mitral E wave deceleration time, peak systolic, and early and late (AR) diastolic pulmonary wenous flow velocities and related variables. In addition, left atrial (LA) function, LV dimensions and hypertrophy and LV systolic performance were assessed. RESULTS Eight dogs (15%) with mild AS had abnormal LV diastolic function, compared with 16 dogs (84%) with moderate or severe AS. Two dogs (3%) had also systolic abnormalities. The flow pattern of delayed relaxation, pseudonormal mitral inflow and restrictive flow were found in 10, 11 and 3 dogs, respectively. IVRT and E:A were heterogeneous in dogs with moderate or severe AS, being either high, normal, or low. Peak AR velocity was significantly higher (p </= 0.05) in dogs with severe AS, and the A duration:AR duration ratio was significantly lower (p </= 0.05) in dogs with moderate and severe AS compared with the other dogs, suggesting decreased LV compliance, increased LV end-diastolic pressure, and normal or increased LA systolic function. Bivariate linear regression analysis revealed significant correlations between the severity of AS based on Doppler and LV hypertrophy (IVSd: r = 0.61, p </= 0.001 and LVPWd: r = 0.46, p </= 0.001) and AS severity and A duration: AR duration (r = -0.64, p </= 0.001). CONCLUSION [corrected] In most boxer dogs with moderate or severe AS, LV diastolic function is abnormal even in the presence of normal systolic performance.

Comparison of computed tomography pulmonary angiography and point-of-care tests for pulmonary thromboembolism diagnosis in dogs

Objectives To evaluate the feasibility of CT pulmonary angiography for identification of naturally occurring pulmonary thromboembolism in dogs using predefined diagnostic criteria and to assess the ability of echocardiography, cardiac troponins, D-dimers and kaolin-activated thromboelastography to predict the presence of pulmonary thromboembolism in dogs. Methods Twelve dogs with immune-mediated haemolytic anaemia and evidence of respiratory distress were prospectively evaluated. Dogs were sedated immediately before CT pulmonary angiography using intravenous butorphanol. Spiral CT pulmonary angiography was performed with a 16 detector-row CT scanner using a pressure injector to infuse contrast media through peripheral intravenous catheters. Pulmonary thromboembolism was diagnosed using predefined criteria. Contemporaneous tests included echocardiography, arterial blood gas analysis, kaolin-activated thromboelastography, D-dimers and cardiac troponins. Results Based on predefined criteria, four dogs were classified as pulmonary thromboembolism positive, three dogs were suspected to have pulmonary thromboembolism and the remaining five dogs had negative scans. The four dogs identified with pulmonary thromboembolism all had discrete filling defects in main or lobar pulmonary arteries. None of the contemporaneous tests was discriminant for pulmonary thromboembolism diagnosis, although the small sample size was limiting. Clinical Significance CT pulmonary angiography can be successfully performed in dogs under sedation, even in at-risk patients with respiratory distress and can both confirm and rule out pulmonary thromboembolism in dogs.