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Introduction: Mitral valve area (MVA) planimetry is used to diagnose and classify mitral stenosis (MS) in humans using two-dimensional and three-dimensional echocardiography (MVA2D and MVA3D). This study aimed to evaluate agreement, feasibility, and observer variability between MVA2D and MVA3D in English Bull Terriers (BT). Our hypotheses were (1) that the MVA of BT is generally smaller than that of breeds with similar body weight and (2) that these techniques could be used to diagnose MS in BTs. Animals: Twenty healthy BTs, 15 healthy Boxers, and 49 BTs with heart disease. Materials and methods: A prospective diagnostic agreement study was conducted. All dogs underwent a thorough clinical examination, conventional transthoracic echocardiography, and three-dimensional echocardiography. Results: Bland–Altman plots (limits of agreement: 0.12–1.5) showed consistent bias and poor agreement between MVA2D and MVA3D. For the 69 BTs, MVA3D (2.1 ± 0.50 cm2) measurements were significantly lower than MVA2D measurements (2.9 ± 0.60 cm2), and healthy BTs had significantly lower MVA parameters than healthy Boxers (p < 0.001). Intraobserver and interobserver variability were excellent for both MVA2D and MVA3D (intraclass correlation coefficient >0.9). Six BTs were diagnosed with MS, with MVA3D less than 1.8 cm2 and a mean transmitral gradient (MTG) of more than 5 mmHg. Conclusions: Both MVA2D and MVA3D are feasible, have low observer variability and can be used to diagnose MS in BTs. For assessing the narrowest orifice area, the preferred method is MVA3D. The smaller MVA in BTs compared to Boxers may indicate some degree of MS.

The left ventricular systolic longitudinal function, traditionally measured by M-mode-derived mitral annular plane systolic excursion (MAPSE), is reduced in feline hypertrophic cardiomyopathy (HCM) and further reduced in cats with left-sided congestive heart failure (CHF). The objectives of this study were to compare longitudinal displacement measured by tissue tracking (TT-LD) and MAPSE in feline HCM and assess these methods' ability to differentiate CHF from preclinical HCM. A further objective was to provide preliminary reference intervals for TT-LD.Eighty-five client-owned cats.A retrospective case-control study. Anatomical M-mode was used to record MAPSE, and TT-LD was recorded by tissue tracking.Reduced longitudinal displacement measured by either MAPSE or TT-LD was significantly associated with CHF in cats with HCM (p 0.036). Receiver-operating characteristic analysis indicated that TT-LD (AUC: 92.9%-97.9%) was more sensitive and specific than MAPSE (AUC: 85.8%-89.1%) for the detection of CHF. A diagnostic cut-off of 2.89 mm for maximal TT-LD in the left ventricular septum resulted in a sensitivity and specificity of 100% and 83.3%, while a diagnostic cut-off of 2.41 mm in the left ventricular posterior wall resulted in a sensitivity of 100% and a specificity of 90%.M-mode-derived mitral annular plane systolic excursion and TT-LD were strongly correlated, but not interchangeable. Longitudinal displacement measured by tissue tracking decreased more with disease severity than traditional MAPSE. Longitudinal displacement may help detect CHF in cats with HCM - with the maximal TT-LD of the left ventricular posterior wall achieving the highest AUC value.

Background Heart failure (HF) is associated with changes in inflammatory and oxidative stress biomarkers. This study aimed to evaluate the changes of a panel of inflammatory and oxidative stress biomarkers in dogs with different stages of HF and its relation with the severity of the disease and echocardiographic changes. A total of 29 dogs with HF as a result of myxomatous mitral valve degeneration or dilated cardiomyopathy were included and classified as stage-A (healthy), B (asymptomatic dogs), C (symptomatic dogs) and D (dogs with end-stage HF) according to the ACVIM staging system. In these dogs an ecnhocardiographic examination was performed and cytokines, and inflammatory and oxidative stress markers were evaluated in serum. Results KC-like was significantly increased in dogs of stage-C (P P P P P Conclusion Our results showed that dogs with advanced HF show increases in positive acute-phase proteins and selected inflammatory cytokines such as KC-like, and decreases in antioxidant biomarkers, indicating that inflammation and oxidative stress act as collaborative partners in the pathogenesis of HF. Some of these biomarkers of inflammation and oxidative stress could have the potential to be biomarkers to monitor the severity of the disease and the effect of treatment.

BACKGROUND Cardiogenic embolism (CE) in cats is a devastating condition primarily associated with hypertrophic cardiomyopathy (HCM). Hypercoagulability may pose a risk for thrombus formation; however, no single test can predict CE development. Platelet microparticles (PMPs) released from platelet membranes are associated with thrombosis in humans. OBJECTIVES The aims were to validate flow cytometric PMP quantification in cats analytically and, in a pilot study, evaluate the procoagulant annexin V (AnV) positive PMP concentration in healthy cats and cats with asymptomatic HCM. METHODS With CD61 as a platelet marker, CD61+ AnV+ PMPs (0.3-1.0 μm) were quantified in citrated whole blood (WB) and platelet-poor plasma (PPP) using flow cytometry. Analyses were performed in 6 healthy cats and 5 cats with asymptomatic HCM. The coefficient of variation (CV) for duplicate (intra-assay) and parallel (inter-assay) analyses were calculated. RESULTS PMP concentrations were quantified with acceptable intra-assay CV for WB (CD61+ /AnV- ; 2.4%, 0.2%-8.4% (median, range), CD61+ /AnV+ ; 3.8%, 0.1%-12.5%) and PPP (CD61+ /AnV- ; 5.0%, 0.7%-12.8%, CD61+ /AnV+ ; 7.4%, 0.5%-15.3%), and acceptable inter-assay CV for WB in 10/11 cats (CD61+ /AnV- ; 6.2%, 1.4%-13.3%, CD61+ /AnV+ ; 6.4%, 0.7%-17.2%), but unacceptable for PPP (CD61+ /AnV- ; 15.6%, 5.8%-42.7%, CD61+ /AnV+ ; 27.8%, 8.4%-77.1%). For WB PMP concentrations, the pilot data demonstrated no differences between healthy cats and cats with asymptomatic HCM (4/5 with left ventricular outflow obstruction) for either the CD61+ /AnV- or the CD61+ /AnV+ PMPs. CONCLUSIONS Only WB PMP concentrations could be quantified reliably in cats in a clinical setting. PMP concentrations did not differ between healthy and asymptomatic HCM cats in this pilot study.

Background: Symmetric dimethylarginine (SDMA) has been increasingly used as a marker of early chronic kidney disease (CKD) in cats, but little is known about the influence of comorbidities on SDMA in this species. Hypothesis: Hypertrophic cardiomyopathy (HCM) and diabetes mellitus (DM), independently of CKD, are associated with changes in serum SDMA. Animals: Ninety-four cats (17 with CKD, 40 with HCM, 17 with DM, and 20 healthy controls). Methods: Case-control study. Clinical examination, echocardiography, ECG, blood pressure, CBC, biochemistry, thyroxine, and SDMA measurement were performed. Urinalysis was performed in controls and cats with CKD and DM. Analysis of variance was used to compare overall differences in the log-transformed SDMA data among groups. A random forest algorithm was applied to explore which clinical and other factors influenced serum SDMA. Results: Median (range) serum SDMA for the renal group (positive control) was 19 (10–93) μg/dL, whereas for the control group (negative control), it was 10 (5–15) μg/dL. For the cardiac and diabetic groups, serum SDMA was 9 (4–24) μg/dL and 7 (3–11) μg/dL, respectively. The renal group had significantly higher SDMA concentrations and the diabetic group significantly lower SDMA concentrations compared to all other groups. Conclusions and Clinical Importance: Serum SDMA concentrations in cats with HCM were not significantly different from those of healthy control cats. Cats with DM, however, had significantly lower SDMA concentrations than controls, a finding that needs further investigation and should be kept in mind when evaluating renal function of cats with this endocrinopathy.

ObjectivesCardiac troponins are sensitive and specific markers of myocardial injury. However, their reliability in renal disease has been questioned owing to possible renal involvement in troponin elimination. The primary objective of the present study was to examine whether serum cardiac troponin I is elevated in cats with compromised renal function and no clinically relevant structural cardiac disease. A secondary objective was to examine whether cardiac troponin I is measurable in the urine of cats with normal and compromised renal function.MethodsThis prospective case-control study included 52 cats (19 with compromised renal function, 19 with primary cardiac disease and 14 healthy controls). For all cats, clinical examination, echocardiography, electrocardiography, blood pressure, complete blood count, biochemistry, serum thyroxine and urinalysis were performed. Cardiac troponin I was measured in the serum and urine of each cat.ResultsMedian (range) serum cardiac troponin I concentrations were 0.052 ng/ml (0.015–0.78 ng/ml) for the renal group, 0.083 ng/ml (0.003–3.27 ng/ml) for the cardiac group and 0.012 ng/ml (0.003–0.14 ng/ml) for the control group. The renal and cardiac groups both had significantly higher serum cardiac troponin I concentrations than the control group, whereas no difference could be detected between the renal and cardiac groups. In the renal group 7/19 cats had measurable urine cardiac troponin I, whereas cardiac troponin I was measurable in the urine of one cat in the cardiac group and two healthy controls. There was no significant correlation between serum and urine cardiac troponin I.Conclusions and relevanceElevated serum cardiac troponin I in cats with compromised renal function may occur without evidence of clinically relevant structural cardiac disease. Moreover, detecting cardiac troponin I in urine is most likely in cats with compromised renal function.

Myxomatous mitral valve disease (MMVD) induces progressive left atrial (LA) enlargement. The LA modulates left ventricular filling and performance through its reservoir, conduit, and contractile function. Assessment of LA size and function may provide valuable information on the level of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD.This prospective study included 205 client-owned dogs of different breeds, 114 healthy dogs, and 91 dogs with MMVD of different disease severities.Using two-dimensional echocardiography, the biplane area-length method was applied to assess LA volume and calculate volumetric indices of LA reservoir, conduit, and contractile function.Left atrial volume and LA stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume2.25mL/kg was the optimal cut off identified for excluding congestive heart failure in dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100%. An active LA emptying fraction24% and/or a LA expansion index126% were suggestive of congestive heart failure in dogs with chronic MMVD with a sensitivity of 77% and a specificity of 89% and a sensitivity of 82% and a specificity of 82%, respectively.Dogs with MMVD appear to have larger LA volumes with poorer LA function. Deteriorating LA function, characterized by a decreasing reservoir and active contractile function, was evident in dogs with MMVD with increasing disease severity.

Objectives To compare a linear and three volume-based two-dimensional echocardiographic methods for measuring LA size: left atrium to aorta ratio (LA/Ao ratio), biplane area-length, biplane modified Simpson and monoplane area-length. Animals One hundred seventy-six client-owned dogs of different breeds, 88 healthy dogs and 88 dogs with myxomatous mitral valve disease of different disease severity. Methods The left apical four- and two-chamber views were used to measure LA volumes. The right parasternal short-axis view at the level of the heart base was used to measure the LA/Ao ratio. Results The biplane area-length method yielded 2.8% larger values than those of the biplane modified Simpson method, consistent across the full range of LA volumes. The monoplane area-length method derived on average 5.8% larger values of LA volume than the biplane area-length method. The difference between these two methods was most pronounced at larger LA volumes. The relation between the LA/Ao ratio and LA volume was curvilinear and with increasing LA size these two methods derived very dissimilar values. Conclusions All methods showed good feasibility and reproducibility, with the volume-based methods having the most favourable intra- and inter-observer variabilities. The LA/Ao ratio underestimates at higher values of LA size compared to the biplane area-length method. LA volume methods may be superior to the LA/Ao ratio in quantification of LA size. The biplane area-length method and biplane modified Simpson method can be used interchangeably. The monoplane area-length measurement may be used as a quick and reliable method for assessment of LA size in clinical practice.

To investigate the prevalence and amplitudes of the electrocardiographic J wave in the Petit Basset Griffon Vendeen compared to 10 other dog breeds.Electrocardiograms from 206 healthy dogs representing 11 dog breeds were included in the study. Besides Petit Basset Griffon Vendeen (PBGV; n = 23) 10 other dog breeds were included.An electrocardiogram ruler was used for measuring the amplitudes of the J waves. The definition of a J wave was a positive deflection at the J point of ≥0.1 mV in more than 1 lead of the bipolar standard limb leads (I, II, III) or the unipolar standard limb leads (aVL and aVF).The prevalence of J waves in the PBGV (n = 23) was 91% (n = 21, standard error (SE) = 5.9%), which was significantly higher compared to seven other dog breeds (p

OBJECTIVES: A missense mutation (A31P) in the cardiac myosin binding protein C gene has been associated with hypertrophic cardiomyopathy (HCM) in Maine Coon cats. The aim of this study was to investigate the effect of A31P on development of HCM, myocardial diastolic dysfunction detected by color tissue Doppler imaging and occurrence of cardiac death during longitudinal follow-up in a cohort of Maine Coon cats.ANIMALS: The original cohort comprised 282 cats (158 of wild-type genotype, 99 heterozygous for A31P and 25 homozygous for A31P).METHODS: Prospective longitudinal study including echocardiography and registration of survival.RESULTS: The median age at the initial examination was 1.7 years (range, 0.8-9.2 years) and 6.4% (18/282) of the cats were diagnosed with HCM. One hundred sixty-five cats were eligible for echocardiographic re-examination, and during an average follow-up period of 2.7 years an additional 6.7% (11/165) of the cats developed HCM. Survival data could be obtained for 262 of the cats originally included, and among these 9.2% (24/262) died of causes that met the study criteria for cardiac death. In the homozygous group 80% (20/25) of cats included were diagnosed with HCM and 48% (12/25) suffered cardiac death during follow-up. These results corresponded to a significantly higher risk for cats homozygous for A31P to develop HCM (pCONCLUSIONS: Homozygosity for A31P was associated with a high penetrance of HCM and a substantial risk for cardiac death in the study population.

Mitochondrial dysfunction and oxidative stress are important players in the development of various cardiovascular diseases, but their roles in hypertrophic cardiomyopathy (HCM) remain unknown. We examined whether mitochondrial oxidative phosphorylation (OXPHOS) capacity was impaired with enhanced mitochondrial oxidative stress in HCM. Cardiac and skeletal muscles were obtained from 9 domestic cats with spontaneously occurring HCM with preserved left ventricular systolic function and from 15 age-matched control cats. Mitochondrial OXPHOS capacities with nonfatty acid and fatty acid substrates in permeabilized fibers and isolated mitochondria were assessed using high-resolution respirometry. ROS release originating from isolated mitochondria was assessed by spectrofluorometry. Thiobarbituric acid-reactive substances were also measured as a marker of oxidative damage. Mitochondrial ADP-stimulated state 3 respiration with complex I-linked nonfatty acid substrates and with fatty acid substrates, respectively, was significantly lower in the hearts of HCM cats compared with control cats. Mitochondrial ROS release during state 3 with complex I-linked substrates and thiobarbituric acid-reactive substances in the heart were significantly increased in cats with HCM. In contrast, there were no significant differences in mitochondrial OXPHOS capacity, mitochondrial ROS release, and oxidative damage in skeletal muscle between groups. Mitochondrial OXPHOS capacity with both nonfatty acid substrates and fatty acid substrates was impaired with increased mitochondrial ROS release in the feline HCM heart. These findings provide new insights into the pathophysiology of HCM and support the hypothesis that restoration of the redox state in the mitochondria is beneficial in the treatment of HCM.

The increasing incidence of orthopaedic methicillin-resistant Staphylococcus aureus (MRSA) infections represents a significant therapeutic challenge. Being effective against MRSA, the role of vancomycin may become more important in the orthopaedic setting in the years to come. Nonetheless, vancomycin bone and soft tissue penetration during infection remains unclear. In eight pigs, implant-associated osteomyelitis was induced on day 0, using a Staphylococcus aureus strain. Following administration of 1,000 mg of vancomycin on day 5, vancomycin concentrations were obtained with microdialysis for 8 h in the implant bone cavity, in cancellous bone adjacent to the implant cavity, in subcutaneous adipose tissue (SCT) adjacent to the implant cavity, and in healthy cancellous bone and healthy SCT in the contralateral leg. Venous blood samples were also obtained. The extent of infection and inflammation was evaluated by post-mortem computed tomography scans, C-reactive protein serum levels and cultures of blood and swabs. In relation to all the implant cavities, bone destruction was found. Ranging from 0.20 to 0.74, tissue penetration, expressed as the ratio of the area under the concentration-time curve from 0 to the last measured value, was incomplete for all compartments except for healthy SCT. The lowest penetration was found in the implant cavity. In conclusion, Staphylococcus aureus implant-associated osteomyelitis was found to reduce vancomycin bone penetration, especially in the implant cavity. These findings suggest that it may be unsafe to rely solely on vancomycin therapy when treating acute osteomyelitis. Particularly when metaphyseal cavities are present, surgical debridement seems necessary. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1093-1098, 2018.

Treatment of post-traumatic and implant-associated osteomyelitis (IAO) includes surgical debridement, removal of implants and long-term antibiotic therapy. The success of antibiotic therapy relies not only on activity towards the infecting pathogen, but also on sufficient penetration of the target site. The aim of the present study was to characterize the local pathological changes associated with reduced penetration of cefuroxime to infected bone implant cavities. Previously, reduced penetration of systemically administrated cefuroxime was demonstrated in the implant cavity of 10 pigs with Staphylococcus aureus IAO present for 5 days. In the present study, a comprehensive histopathological characterization of the peri-implant bone tissue was performed and correlated with the reduced penetration of cefuroxime. In two pigs, the levels of oxygen, pyruvate and lactate was estimated in the implant cavity. A peri-implant pathological bone area (PIBA) developed with a width of 1.2 up to 3.8 mm. PIBAs included: (1) suppuration, resulting in destruction of the implant cavity contour, and (2) a non-vascular zone of primarily necrotic bone tissue. A strong negative correlation was seen between PIBA width and cefuroxime area under the concentration time curves (AUC[0-last]) and peak concentration of cefuroxime (Cmax). All metabolic measurements demonstrated hypoxia. In conclusion, subacute suppurative bone inflammation with local tissue destruction can result in decreased penetration of antibiotics and insufficient oxygen supply.

Background Myocardial injury detected by cardiac troponin I and T (cTnI and cTnT) in cardiac disease is associated with increased risk of death in humans and dogs. Hypothesis Presence of myocardial injury predicts long-term death in cats with hypertrophic cardiomyopathy (HCM), and ongoing myocardial injury reflects change in left ventricular wall thickness over time. Animals Thirty-six cats with primary HCM. Methods Prospective cohort study. Cats with HCM were included consecutively and examined every 6 months. Echocardiography, ECG, blood pressure, and serum cTnI and cTnT were evaluated at each visit. Cox proportional hazards regression analysis was performed to evaluate prognostic potential of serum troponin concentrations at admission and subsequent examinations. Correlations were used to examine associations between troponin concentrations and cardiac hypertrophy. Results Troponin concentrations at admission were median [range] 0.14 [0.004–1.02] ng/mL for cTnI, and 13 [13–79.5] ng/L for cTnT. Both were prognostic for death (P = .032 and .026) as were the last available concentrations of each (P = .016 and .003). The final cTnT concentration was a significant predictor of death even when adjusting for the admission concentration (P = .043). In a model containing both markers, only cTnT remained significant (P = .043). Left ventricular free wall thickness at end-diastole (LVFWd) at admission was correlated with cTnI at admission (r = 0.35, P = .035), however no significant correlations (r = 0.2–0.31, P = .074–.26) were found between changes in troponin concentrations and left ventricular thickness over time. Conclusions and Clinical Importance Myocardial injury is part of the pathophysiology leading to disease progression and death. Low sensitivities and specificities prevent outcome prediction in individual cats.

Cardiovascular lesions are commonly diagnosed postmortem in scarlet ibis (Eudocimus ruber), but antemortem diagnosis is rare. The aim of this study was to evaluate the cardiovascular health of a zoo population (n = 44) of apparently healthy, adult, scarlet ibis. A cross-sectional study design was employed whereby each animal was manually restrained for physical examination, phlebotomy, and echocardiographic examination performed with a 12-MHz transducer and a ventromedial approach, and observed intervals were calculated for 12 parameters. Seven individuals from the study population had high left-sided mid-ventricular velocities (2.59-5.89 m/sec) compared with values in other species. Follow-up examination suggested that these mid-ventricular obstructive lesions were dynamic and transient in nature rather than caused by fixed lesions within the outflow tract and may therefore be associated with stress. Conscious echocardiography proved to be feasible, although, unsurprisingly, the stress response in nonhabituated birds appeared to increase blood flow velocities. Handling protocols likely have a significant effect on echocardiographic parameters and should be taken into consideration when interpreting findings. Serum cholesterol concentrations were generally high (7.4-13.0 mmol/L), and further work is required to investigate the relationship between circulating cholesterol and the development of atherosclerosis in scarlet ibis. Serum cardiac troponin I concentrations were measured, and four animals were identified with suspected elevated levels, likely indicative of myocardial damage.

Hypertrophic cardiomyopathy (HCM) is a myocardial disorder, with complications including heart failure, thromboemboli and sudden death. Human and feline HCM (fHCM) are clinically comparable, thus fHCM may serve as a spontaneous animal model. fHCM in Maine Coon (MC) cats is associated with the p.A31P mutation in the cMyBP-C protein. The mutation is located in the cMyBP-C C0-domain which is known to interact with actin. The presence and levels of the wild type and mutated protein in heart tissue from mutant and wild type MC cats were examined by SDS-PAGE and mass spectrometry (MS). Quantitative yeast-2-hybrid (Y2H) protein-protein interaction analysis was used to assess the effect of the mutation on C0C1/actin interaction. The NMR-based structure of the C0 domain was used to calculate the energetic consequence of replacing alanine with a proline residue. In the homozygous MC cat, the mutated cMyBP-C protein was present, and cMyBPC-C levels were not reduced compared to that of the wild type cat. However, the interaction of actin with mutant cMyBP-C C0C1 was reduced compared to that of wild type. This may be because the substitution of the alanine with proline in position 31 was energetically highly unfavorable and resulted in only one hydrogen bond within the anti-parallel beta-strand compared to two hydrogen-bonds for alanine, possibly destabilizing the structure of the actin-interacting domain. The p.A31P mutation is present in cardiac tissue and the most likely pathogenic mechanism is interference with contractility by reducing binding of the C0C1 domain of cMyBP-C to actin.

HYPERTROPHIC cardiomyopathy (HCM) is the most common cardiac disease in cats, associated with severe myocardial structural and ultrastructural changes (Abbott 2010, Christiansen and others 2015). In human beings, HCM is frequently inherited as an autosomal dominant trait caused by mutations in genes encoding sarcomeric proteins, including the myosin-binding protein C (MYBPC3) and the cardiac troponins (Gomes and Potter 2004, Cambronero and others 2009). In cats, familial mutations have been described in the MYBPC3 protein in Maine Coons (A31P) and ragdolls (R820W) (Meurs and others 2005, 2007). Cats homozygous for these mutations have a high risk of developing a fatal, progressive HCM (Meurs and others 2005, Borgeat and others 2014b). While additional causative mutations associated with feline HCM have yet to be discovered, several other breeds are considered predisposed. Cardiac troponin I (cTnI) is a sensitive and specific marker of cardiomyocyte injury. Serum cTnI is generally increased in HCM patients and is associated with increased risk of mortality (Borgeat and others 2014a, Langhorn and others 2014). The cause of myocardial injury is believed to be mild chronic ischaemia due to a range of neurohormonal, inflammatory and vascular factors (Langhorn and others 2014). Additionally, effects of specific mutations and sex on myocardial injury in HCM have been suspected in human studies (Cambronero and others 2009, Kubo and others 2010), and one study on ragdolls similarly reported a difference in cTnI concentration between mutation-positive and mutation-negative cats (Borgeat and others 2015). The aim of this study was …

Background: Familial hypertrophic cardiomyopathy (HCM) has been described previously in British Shorthair cats (BSH), but until now, no reports have been published describing the prevalence of the disease within this breed. Objectives: The aim of this study was to assess the prevalence of HCM in a large cohort of BSH and to evaluate the effect of sex, weight, and increasing age as potential risk factors for this disease. Animals: Three hundred and twenty-nine BSH presented for routine HCM screening during a 4-year period. Methods: Prospective cross-sectional study in which all cats were screened for HCM by conventional echocardiography. Results: A total of 329 cats were examined, 214 females and 115 males, with a median age of 2.3 years (range, 0.8–14.1). Twenty-eight cats (8.5%) were classified as HCM-positive, 14 (4.3%) as equivocal, 282 (85.7%) as HCM-negative, and 5 (2.1%) were diagnosed with other cardiac diseases. The median age for diagnosis of HCM was 2.7 years (range, 0.9–14.1). Male cats had a significantly higher occurrence of HCM (20.4%) compared with the females (2.1%) corresponding to an odds ratio of 7.89 (95 % CI, 2.54–28.08) for males versus females adjusted for age and weight (P < .001). Conclusion: The BSH in our cohort had a high prevalence of HCM, often of early onset and with a significant male sex predisposition. We strongly recommend echocardiographic screening in this breed, especially cats used for breeding.

Haematological and biochemical parameters were studied prospectively in 48 dogs naturally infected with Angiostrongylus vasorum in a primary care setting. Samples for analysis were obtained when treatment was started and 42days afterwards. Prior to treatment, 21% of affected dogs exhibited eosinophilia, whereas increased total white blood cell (WBC) counts and neutrophilia were observed in only 4.2%. WBC counts and concentrations of neutrophils, eosinophils and monocytes decreased significantly from days 0 to 42, indicating that, even in dogs without elevated absolute blood values, a low grade inflammatory response may be present in dogs with A. vasorum infection. Biochemical changes (especially an increase in serum globulins and a decrease in serum fructosamine) were in agreement with the findings of other studies. The results show that the diagnosis of canine angiostrongylosis should not be excluded based on unremarkable haematological and blood biochemical parameters. They also support our recent finding that a low serum fructosamine concentration may be associated with infection with A. vasorum.

Canine pulmonary angiostrongylosis is an emerging snail-borne disease causing verminous pneumonia and coagulopathy in dogs. The parasite is found in Europe, North and South America and Africa, covering tropical, subtropical and temperate regions. Its distribution has been characterised by isolated endemic foci, with only sporadic occurrences outside these areas. In the last two decades, the literature has been dominated by several case reports and small case series describing sporadic disease in old or new endemic areas. Case reports and experimental studies with high doses of infective third stage larvae may not reflect what happens under field conditions. There is insufficient understanding of the spread of infection and the dynamic consequences of this parasite in the canine population. This review discusses the biology, epidemiology, clinical aspects and management of canine pulmonary angiostrongylosis.

Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present. Herein we propose that automated volume histogram analysis can yield data that allow differentiation of normal from abnormal lung, and that the magnitude of disease will have an association with objective CT indices. Data from pulmonary CT images from 34 foxes (six uninfected controls and 28 infected with Angiostrongylus vasorum, subdivided by age and infective dose) were available. Lung tissue was segmented from surrounding tissue using an automated segmentation method. A volume histogram showing voxel frequency for each CT number in the range -1024 to -250 HU was created from the entire image stack from each fox. Using these data, the inter-quartile range and the CT number at the 95th percentile were determined. The results showed that segmentation could be readily achieved but that areas of severely diseased lung were excluded. Based on two-way analysis of variance for both the inter-quartile range and the CT number at the 95th percentile, both quantities were significantly affected by the infection status of the animal and were related to worm burden (P < 0.001). The study shows that this form of analysis is readily achieved and provides quantitative data that can be used to assess disease severity, progression, and response to treatment.

Objectives This study was conducted to estimate the incidence of aortic stenosis (AS) in a group of Boxers evaluated by auscultation, ECG, blood pressure measurement and Doppler-echocardiography. Background The Boxer is a breed at significantly increased risk of AS. The prevalence of murmurs and Doppler-echocardiographic findings consistent with AS in this breed is reportedly high. Animals, materials and methods Eighty-nine Boxers were evaluated by auscultation, and final murmur grade recorded after stress testing. Doppler echocardiography was performed in fifty-five adult Boxers. Electrocardiograms (ECG, n = 53), non-invasive blood pressure measurement ( n = 32), and Holter monitoring ( n = 24) were performed in selected dogs. Degree of AS was based on the aortic peak flow velocity (Ao PFV). Final Ao PFV was recorded as the highest value obtained after stress testing. AS was defined as an Ao PFV > 2 m/s on continuous wave Doppler, using the subcostal window. Pressure gradients (Δ p ) were calculated using the modified Bernoulli equation (Δ p = 4 V 2 ). Mild AS was defined as Δ p = 16–40 mmHg, moderate AS Δ p = 40–75mmHg, and severe AS Δp > 75mmHg. Results 62% of adult Boxers evaluated by echocardiography had an Ao PFV > 2 m/s suggestive of AS. Systolic basilar ejection murmurs were diagnosed in 73%. Murmur intensity showed a statistically significant correlation with Ao PFV ( p Conclusion The study reports on systolic murmurs and Doppler-echocardiographic findings consistent with AS, as well as ECG and blood pressure measurements in a sample of pure-breed Boxers.

SUMMARY Objective This study investigatest the influence of sampling period duration, time of day, age, sex, body weight and degree of mitral valve prolapse (MVP) on various measures of heart rate variability (HRV) in the dog. The correlations between the HRV parameters were also investigated. Background Holter recording is increasingly being used in dogs but method studies are sparse. Previous studies suggest that canine MVP is related to a high vagal tone. Methods Twenty-four hour ambulatory electrocardiographic recording (Holter recording) was performed on 24 Dachshunds (11 males and 13 females). All dogs were between 2 and 6 years of age and without heart murmurs. Results The majority of the HRV parameters depended on the duration of the sampling period and they generally exhibited circadian variation. Higher values in males than in females were found for several parameters, especially low frequency power (LF) during 24 hour recording (P = 0.0002). Although a number of HRV parameters correlated positively with MVP severity and negatively with age, the influence of these two factors was not clear and consistent in all sampling periods. The degree of MVP related to the number of episodes of supraventrucular tachycardia occuring during the day. Generally, a large inter-individual variation was found with regard to the HRV parameters and the correlations between the parameters were weaker than correlations reported in humans. Two manually measured ECG parameter related to vagal tone correlated strongly with 2 out of 3 vagal indexes derived from the HRV analysis. Conclusion HRV parameters are influenced especially by sex and sampling period duration, but also by age and MVP status in young, clinically healthy Dachshunds.

The diagnostic accuracy of the urinary cortisol:creatinine ratio (CCR), with the cortisol being measured by ELISA, was evaluated by subjecting data from 18 dogs with and 20 dogs without hyperadrenocorticism to receiver operating characteristic (ROC) curve analysis. The area under the ROC curve (W 0.93, SE(w) 0.044) was much higher than 0.5, indicating that the CCR did distinguish between dogs with and without hyperadrenocorticism. A cutoff value of about 60 x 10(-6) was associated with the highest sensitivity (1.0) and specificity (0.85). At the disease prevalence rate of the present study (0.47), the positive and negative predictive values were 0.87 and 1.0, respectively. These numbers indicate that canine hyperadrenocorticism may be safely excluded when the CCR is below 60 x 10(-6) but that a test of higher specificity (eg, the ACTH stimulation test) should be used to confirm the diagnosis of canine hyperadrenocorticism when the CCR is above 60 x 10(-6).

The left atrium (LA) of the heart is a validated marker of clinical and subclinical cardiovascular disease. Since the LA is a three-dimensional structure, volume-based methods of chamber quantification might be more accurate than linear methods. The aims of this study were to establish the feasibility and reproducibility of biplane two-dimensional echocardiographic LA volume measurements and to provide reference ranges for LA volume and phasic function in adult dogs (n=237) without cardiovascular disease. The study also assessed the effects of bodyweight (BW), breed, sex, age and heart rate (HR) on LA volume and function. The biplane area-length method was used to calculate LA volumes from the left apical four- and two-chamber views. LA volume and function were correlated with body size and there were significant breed differences. For dogs of all sizes and breeds, LA maximal volume had a 95th percentile of 0.92 mL/kg. There was no correlation between age or sex and LA volume or LA reservoir function, but conduit function decreased and booster pump function increased with age. LA volume and function varied with HR. LA size was calculated using the biplane area-length method, with good reproducibility and little inter-observer variability. The reference ranges presented for LA volume and function in healthy dogs could be used to refine the diagnostic criteria for the assessment of LA enlargement and altered function by conventional echocardiography.

Yorkshire terriers may be prone to respiratory disease; however, limited epidemiological information is available. A cross-sectional study design was used to compare the prevalence of respiratory signs in Yorkshire terriers with the prevalence in a population of dogs in general and to identify risk factors for respiratory clinical signs within the Swedish population of Yorkshire terriers. Data on clinical signs and risk factors were obtained from a questionnaire. The prevalence of respiratory signs in general (RS) was significantly higher among Yorkshire terriers compared with control dogs (RS 56.3 per cent and 23.0 per cent), and likewise more frequent respiratory signs (FRS) (26.0 per cent and 5.0 per cent). Age, sex and breed were shown to be significant risk factors, and an interaction between age and sex was discovered. The study indicated a sex ratio reversal in the prevalence of RS – the probability of females having RS increased with advancing age, while the probability for males was fairly constant.

Angiostrongylus vasorum has been recognised as a cause of respiratory and circulatory distress among dogs in southwestern France for more than a decade, and the nematode now appears to be of increasing importance in the British Isles and Denmark. The aim of this review is to give a concise account of present knowledge of this intriguing parasitosis.

The rectal temperature is frequently measured in the morning on a daily basis in hospitalized dogs. Besides comparing the measured temperature to a population-based reference interval, it may also be of interest to evaluate the differences between consecutive measurements in order to follow the health status of a particular dog. In veterinary clinical chemistry, a parameter referred to as the critical difference, which can be used to judge if the difference between two consecutive measurements may be safely ascribed to random variation or not, has recently been introduced. The purpose of the present study was to obtain an estimate of the critical difference of the rectal temperature based on measurements of the rectal temperature in clinically healthy dogs in a hospital environment. The rectal temperature was measured in a standardized manner on 6 different days in 7 dogs. The total variance was estimated as 0.1015. The inter-individual variance was 0.0428, and the intra-analytical variance including the analytical variance was 0.0587. From these components of variance, the critical difference was calculated as 0.69 degrees C. Thus, the rectal temperature measured in the morning in hospitalized dogs can be expected to fluctuate about 0.7 degrees C from day to day due to random variation alone.

The study was performed to investigate the difference in the concentration of several haematological and clinical chemical blood components in blood obtained from the cephalic and external jugular veins in 23 dogs. A total of 17 laboratory tests were analysed and, except for two clinical chemical blood components, there was no decisive difference in the test results obtained in blood samples collected from the cephalic and external jugular vein in dogs. For creatinine and potassium, however, there was a significant difference in the test results between the two veins, the highest results in general being measured in jugular venous blood. These findings indicate that it may be advisable to establish standardised procedures when collecting blood samples and make adjustments for the difference in test results when interpreting them.

This case report describes the clinical, imaging, clinical pathology and necropsy findings in a five-year-old male Border collie with low output cardiac failure. The heart was enlarged by infiltrative lymphosarcoma.

Four dogs with acute neurological signs caused by haemorrhages in the central nervous system were diagnosed with Angiostrongylus vasorum infection as the underlying aetiology. Two dogs presented with brain lesions, one dog with spinal cord lesions and one with lesions in both the brain and spinal cord. Only one dog presented with concurrent signs of classical pulmonary angiostrongylosis (respiratory distress, cough), and only two dogs displayed overt clinical signs of haemorrhages. Results of coagulation assays were inconsistent. Neurological signs reflected the site of pathology and included seizures, various cranial nerve deficits, vestibular signs, proprioceptive deficits, ataxia and paraplegia. One dog died and three were euthanised due to lack of improvement despite medical treatment. This emphasises canine angiostrongylosis as a potential cause of fatal lesions of the central nervous system and the importance of including A. vasorum as a differential diagnosis in young dogs with acute neurological signs in Denmark.

Background In Maine Coon (MC) cats the c.91G > C mutation in the gene MYBPC3, coding for cardiac myosin binding protein C (cMyBP-C), is associated with feline hypertrophic cardiomyopathy (fHCM). The mutation causes a substitution of an alanine for a proline at residue 31 (p.A31P) of cMyBP-C. The pattern of inheritance has been considered autosomal dominant based on a single pedigree. However, larger studies are needed to establish the significance of cats being heterozygous or homozygous for the mutation with respect to echocardiographic indices and the probability of developing fHCM. The objective of the present study was to establish the clinical significance of being homozygous or heterozygous for the p.A31P cMyBP-C mutation in young to middle-aged cats. Methods The cohort consisted of 332 MC cats, 282 cats < 4 years (85%). All cats were examined by 2-D and M-mode echocardiography. DNA was extracted from blood samples or buccal swabs and screened for the p.A31P cMyBP-C mutation in exon 3 of the gene, using polymerase chain reaction followed by DNA sequencing. Results The fHCM prevalence was 6.3% in the cohort. Eighteen cats were homozygous and 89 cats were heterozygous for the mutation. The odds ratio for having fHCM for homozygous cats was 21.6 (95% confidence interval 7.01-66.2) - when the group of equivocal cats was categorized as non-affected. Overall, 50% of the cats that were homozygous for the mutation had fHCM. p.A31P heterozygosity was not associated with a significant odds ratio for fHCM. In cats in the 4 to 6 years of age range a similar, non significant, odds ratio was seen in heterozygous cats. Only two cats over four years were homozygous and both were diagnosed with fHCM. Conclusion As there is no significant odds ratio associated with being heterozygous for the pA31P cMyBP-C mutation at this age, the mutation must have a very low penetrance in this group. From our data it would appear that most MC cats that develop fHCM due to the p.A31P mutation prior to the age of approximately 6 years do so because they are homozygous for this mutation.

Summary The present study is concerned with the critical difference, which may help to judge whether or not the difference between two consecutive measurements with a certain probability (i.e. 95 percent) may be ascribed to natural variation. Knowledge of the applicability of the critical difference in veterinary medicine is sparse and therefore, to justify future use of the critical difference, it is important to know whether or not the critical difference performs as expected. The hypothesis to be tested in this study was that at least 95 percent of the differences between consecutive measurements, that have been obtained in animals where the component measured is known to be unchanged, should be within the critical difference. From previous studies it was known that a low-sodium diet had no influence on the plasma potassium concentration. The critical difference of the plasma potassium concentration in dogs was calculated as 0.5 mmol/l. using weekly measurements of this plasma component in a group of twenty healthy dogs. To test the hypothesis, this value was compared to the differences between consecutive weekly measurements of this plasma component in another group of eight dogs fed a low-sodium diet for five weeks. In agreement with previous studies, the plasma potassium concentration in the eight dogs did not change significantly during the feeding experiment. Of the fourty differences between consecutive weekly measurements, thirty-six were within the critical difference. This number was not different from the number expected from the hypothesis and thus, the critical difference performed as expected. Furthermore, the present study also indicated that a critical difference calculated from one group of dogs can be used to evaluate differences between consecutive measurements in another group of dogs under other dietary and management conditions.

A one-year-old intact female, Danish shorthaired pointer was referred to the emergency service with a history of acute collapse and pale mucous membranes after a month of reduced activity but with no other clinical signs. An ultrasound examination of the abdomen indicated the presence of a large amount of free fluid with no obvious cause such as neoplasia or splenic rupture. Fluid analysis had the macroscopic appearance of blood with no signs of infection or neoplasia. Multiple Angiostrongylus vasorum L1 larvae were revealed on a direct rectal faecal smear. The dog was treated with fenbendazole 25 mg/kg orally once daily for 20 days and given supportive treatment. The dog was stabilised on this treatment. Haemoabdomen is a clinical sign where surgical intervention is often considered an integral part of the diagnostic investigation (i.e., laparotomy) or treatment. Failing to make the diagnosis of canine angiostrongylosis before performing surgery may have a serious adverse affect on the outcome. Consequently, in areas where A. vasorum is enzootic, a Baermann test and a direct faecal smear should be included in the initial diagnostic investigation of all dogs presenting with bleeding disorders of unknown origin.

Objectives: To evaluate the occurrence of aortic stenosis and establish echocardiographic reference values in the Dogue de Bordeaux in Denmark. Methods: Fifty-three dogs were auscultated for evidence of a cardiac murmur and a full echocardiographic examination was performed. The criterion for the diagnosis of aortic stenosis was a peak aortic velocity greater than 2·5 m/s from a subcostal transducer location. Results: A left-basilar ejection murmur was detected in 38 (72 per cent) of the dogs. An aortic ejection velocity greater than 2·5 m/s was identified in 9 (17 per cent) of the dogs from a subcostal view. The aortic annulus in Dogue de Bordeaux was smaller than that considered normal in other breeds with comparable body size. Furthermore, a decreased aortoseptal angle was noticed in dogs with aortic stenosis. Clinical Significance: The Dogue de Bordeaux may be highly predisposed to aortic stenosis. The small aortic annulus noted in healthy and affected Dogue de Bordeaux and a decreased aortoseptal angle noted in affected dogs in this study might reflect key aetiological features in the development of aortic stenosis.

To evaluate by echo- and electrocardiography the cardiac effects of sedation with detomidine hydrochloride, romifidine hydrochloride or acepromazine maleate in horses.An experimental study using a cross-over design without randomization.Eight clinically normal Standardbred trotters.Echocardiographic examinations (two-dimensional, guided M-mode and colour Doppler) were recorded on five different days. Heart rate (HR) and standard limb lead electrocardiograms were also obtained. Subsequently, horses were sedated with detomidine (0.01 mg kg(-1)), romifidine (0.04 mg kg(-1)) or acepromazine (0.1 mg kg(-1)) administered intravenously and all examinations repeated.Heart rate before treatment with the three drugs did not differ significantly (p = 0.98). Both detomidine and romifidine induced a significant decrease (p0.001) in HR during the first 25 minutes after sedation; while acepromazine had a varying effect on HR. For detomidine, there was a significant increase in LVIDd (left ventricular internal diameter in diastole; p = 0.034) and LVIDs (left ventricular internal diameter in systole; p0.001). In addition, a significant decrease was found in IVSs (the interventricular septum in systole; p0.001), LVFWs (the left ventricular free wall in systole; p = 0.002) and FS% (fractional shortening; p0.001). The frequency of pulmonary regurgitation was increased significantly (p0.001). Romifidine induced a significant increase in LVIDs (p0.001) and a significant decrease in IVSs (p0.001) and FS% (p = 0.002). Acepromazine had no significant effect upon any of the measured values.and clinical relevance The results indicate that sedation of horses with detomidine and to a lesser extent romifidine at the doses given in this study has a significant effect on heart function, echocardiographic measurements of heart dimensions and the occurrence of valvular regurgitation. Although the clinical significance of these results may be minimal, the potential effects of sedative drugs should be taken into account when echocardiographic variables are interpreted in clinical cases.

A randomized, blinded, controlled multicentre field trial study was conducted to evaluate the efficacy and safety of imidacloprid 10%/moxidectin 2.5% spot-on solution and fenbendazole in treating dogs naturally infected with Angiostrongylus vasorum. Dogs were randomly treated either with a single dose of 0.1 ml/kg bodyweight of imidacloprid 10%/moxidectin 2.5% spot-on solution or with 25 mg/kg bodyweight fenbendazole per os for 20 days. The study period was 42 days with dogs being examined on days 0, 7 and 42. The primary efficacy parameter was the presence of L1 larvae in faecal samples evaluated by a Baermann test from three consecutive days. Thoracic radiographs performed on each visit were being taken as a paraclinical parameter to support the results of the Baermann test. Twenty-seven dogs in the imidacloprid/moxidectin group and 23 dogs in the fenbendazole group completed the study according to protocol. The efficacies of the two treatment protocols were 85.2% (imidacloprid/moxidectin) and 91.3% (fenbendazole) with no significant difference between treatment groups. On radiographic evaluation pulmonary parenchyma showed similar improvement in each group. No serious adverse effects to treatment were recorded: most of the minor adverse effects were gastrointestinal such as diarrhea (nine dogs), vomitus (eight dogs) and salivation (three dogs). In general, these adverse effects were of short duration (1-2 days) within the first few days after treatment start and required little or no treatment. This prospective study demonstrates that both treatment protocols used are efficacious under field conditions, that treatment of mildly to moderately infected dogs with either of these protocols is safe and yields an excellent prognosis for recovering from the infection.

Objective—To evaluate changes over time in echocardiographic measurements in young Standardbred racehorses undergoing training and racing and determine whether there was any relationship between cardiac dimensions and racing performance. Design—Longitudinal observational study. Animals—103 horses. Procedure—2-dimensional and M-mode echocardiography was performed 4 times at 6-month intervals. Results—Significant cardiac enlargement took place during the study period as indicated by increases in left ventricular internal diameter in diastole (LVIDd), estimated left ventricular muscle mass (LV mass), and mean wall thickness attributable to eccentric left ventricular hypertrophy. Estimated body weight was positively correlated with left ventricular size, and males had significantly larger LVIDd and LV mass than did females. Horses that were racing regularly had larger LVIDd and LV mass than did unraced horses. A significant relationship between left ventricular size and racing performance was observed. The relationship was strongest at the time of the fourth examination. Conclusions and Clinical Relevance—Results suggest that age must be taken into account when interpreting results of echocardiography in young Standardbred racehorses because significant cardiac enlargement takes place with age and training. A larger heart was found in horses that were racing, and size of the heart was correlated with athletic performance of the horse. (J Am Vet Med Assoc 2005;226: 1881–1887)

The purpose of this study was to assess the intraobserver variation of various echocardiographic measures in standardbred trotters. Serial echocardiographic examinations were carried out on eight standardbred mares by one ultrasonographer for 5 separate days. During each examination, five nonconsecutive cardiac cycles (frames) were recorded and an average obtained for each individual measure. Various echocardiographic measures were obtained by use of two-dimensional (2-D), M-mode, color flow Doppler and pulsed wave Doppler echocardiography. The total variation in the echocardiographic measurements was split into three levels: the variation between horses, the day-to-day variation within individual horses, and finally the variation within horse on the same day of examination (intercardiac cycle variation). The intraclass correlation coefficient (ICC) was calculated for each measure. The ICC represents the variability of the measurements because of differences between the horses. In general the 2-D, M-mode and color flow Doppler measures had higher ICC values (ICC from 0.63 to 0.95) than the pulsed wave Doppler measures (ICC from 0.24 to 0.46), and the former measures were more repeatable than the pulsed wave measures. Exceptions to that were left ventricular free wall in diastole, the pulmonary artery in systole and the left ventricular mass, which all had low repeatability (ICC from 0.22 to 0.49). The results were used to calculate the relative differences that must be detected to diagnose a statistically significant change between two measurements in an individual horse. Differences from 4.2% to 21.8% must be achieved to document significant changes between serial measurements. A general tendency is that the color flow and pulsed wave Doppler measures require a larger relative difference (11.4-21.8%) between the measures to point out statistically significant cardiac changes than the 2-D and M-mode measures (4.2-13.9%).

Anechoic, spherical cystic lesions are important findings on ultrasound examination. In polycystic renal disease of cats, they may be the only ultrasonographic sign of disease. This study assesses the accuracy of ultrasound, as used in a veterinary setting, for the detection of cysts. Using a spherical lesion ultrasound imaging phantom and 7.5- to 8-MHz linear array transducers, images of cysts of 2- and 4-mm diameter were created at various imaging depths from 0 to 6 cm. These were digitized and given to a panel of readers for interpretation. Area under receiver operating characteristic curves were used to evaluate test accuracy. It was shown that test accuracy was different at different imaging depths and differed with machines of differing price category. It is suggested that when setting standards for quality control in ultrasound, criteria used might be better related to imaging outcome studies rather than to aspects of machine specification.

Polycystic kidney disease (PKD) in Persian cats has been increasingly reported and compared to human autosomal dominant polycystic kidney disease (ADPKD) in the last decade. In cats, however, few studies have dealt with the occurrence and hormonal determinants of hypertension, one of the most common extrarenal manifestations of ADPKD in humans. The purpose of this study was to compare Persian cats >4 years old with PKD to unaffected control cats with regard to blood pressure (BP), plasma renin activity (PRA), serum aldosterone concentration, plasma atrial natriuretic peptide (ANP) concentration, and aldosterone-to-renin ratio (ARR). Three gender- and age-matched groups were studied, each consisting of 7 cats: (1) a control group without cysts, (2) a group with mild PKD, and (3) a group with severe PKD (multiple cysts and renal enlargement). Mild renal insufficiency was found in only 1 of 14 cats with PKD. Cats with PKD had a higher mean arterial pressure (P = .04) and more often had a high ARR (P = .047) than did control cats. Tendencies toward higher diastolic and systolic arterial pressures (DAPs and SAPs, respectively) and lower PRAs were observed in cats with PKD compared to controls (.05 < P < or = .1). No significant differences were found between the groups in serum aldosterone and plasma ANP concentrations. None of the cats had echocardiographic evidence of cardiac hypertrophy. In conclusion, cats with PKD had a minor increase in mean arterial pressure compared to control cats, and half of the cats had a high ARR.

M-mode echocardiograms were recorded from 62 giant breed dogs without historical, clinical, electrocardiographic and roentgenologic signs of heart disease, from six dogs with asymptomatic dilated cardiomyopathy (DCM, NYHA class I), and 13 dogs with symptomatic DCM (NYHA class III-IV). There was a general trend that several echocardiographic parameters were significantly in control Great Danes as compared to Newfoundlands and Irish Wolfhounds. There were substantial differences in left ventricular size both in systole and diastole and in systolic indices of the left ventricle between the control group, the asymptomatic dogs and symptomatic dogs with DCM (P = 0.0001). There was also a significant decreased in the interventricular septum thickness (P = 0.0001) and left ventricular free wall thickness in systole (P = 0.002) and diastole (P = 0.005) between the three groups. Furthermore, the left atrial/aortic ratio was significantly different between the three groups (P = 0.0001). It was concluded that this study established echocardiographic reference values in giant breed dogs which may be useful in the study of heart diseases in giant breed dogs.

Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were assessed in 23 dogs, nine of which had asymptomatic dilated cardiomyopathy (DCM) (New York Heart Association [NYHA] class I), eight had symptomatic DCM (NYHA class III) and six had severe congestive heart failure due to DCM (NYHA class IV). None of the dogs had received any drugs before the study. PRA was increased in dogs with DCM (NYHA classes III and IV) (median values 3.8 and 30.8 ng ml-1 hour-1) compared with normal dogs (median 0.89 ng ml-1 hour-1). However, PRA was only marginally increased in dogs with DCM NYHA class I (P = 0.06). The PAC was also increased in dogs with DCM (NYHA classes III and IV) (median values 123 and 600 pg ml-1) compared with normal dogs (median 61 pg ml-1). The PAC was not significantly increased in the early stage of DCM (NYHA class I). It was concluded that in dogs with DCM, the activity of the renin-angiotensin system (RAS) was increased in NYHA functional classes III and IV, and that the increase was correlated with the severity of the disease. The fact that the RAS tended to be activated in dogs with asymptomatic DCM supports the rationale of early therapeutic intervention with inhibitors of the angiotensin-converting enzyme (ACE) as first line therapy in congestive heart failure.

The renin-angiotensin system has important pathophysiologic implications in the development of congestive heart failure. The activity of the renin-angiotensin system early in the course of heart disease and heart failure in dogs was evaluated by measuring the plasma renin activity (PRA) and plasma aldosterone concentration (PAC) in 18 Cavalier King Charles Spaniels with asymptomatic or mildly symptomatic mitral valvular insufficiency, and in 18 healthy Cavalier King Charles Spaniels. All dogs were unmedicated and had no other diseases. The PRA was high in the dogs with mitral valvular insufficiency (median 3.44 ng/mL/h, interquartile interval 2.59 to 8.66 ng/mL/h) compared with the controls (median 2.51 ng/mL/h, interquartile interval 1.44 to 3.58 ng/mL/h). The PAC was also higher in the dogs with mitral insufficiency (median 53 pg/mL, interquartile interval 33 to 138 pg/mL) than in the control group (median 27 pg/mL, interquartile interval 11.5 to 54 pg/mL). However, there was considerable overlap between the 2 groups in both PRA and PAC. It was concluded from these data that there is early activation of the renin-angiotensin system in some Cavalier King Charles Spaniels with mitral valvular insufficiency. Further prospective studies are needed to determine if early intervention with angiotensin-converting enzyme inhibitors will be valuable in this group of patients.

The ultrasonographic findings in a one-and-a-half-year-old female basenji with immunoproliferative enteropathy are described. On ultrasonographic examination, generalised thickening of the small bowel wall was found, ranging between 4 and 6 mm. The normal layered appearance of the intestinal wall was replaced by three distinct layers; an innermost enlarged hyperechogenic layer; an enlarged poor echogenic layer, and an outer hyperechogenic layer. These findings are consistent with the histopathological appearance of this particular chronic inflammatory bowel disease, since the inner layer probably represents the infiltrated mucosa, the middle layer the infiltrated lamina propria and the outer layer the serosa. Thus, the ultrasonographic finding of generalised thickening of the intestinal wall in a basenji presenting with chronic diarrhoea, weight loss, anorexia or vomiting is strongly indicative of immunoproliferative enteropathy.

The purpose of the present study was to quantify some of the short term responses of the renin-angiotensin system (RAS) to a recommended dosage of the angiotensin-converting enzyme inhibitor enalapril in clinically healthy dogs fed a normal-sodium and a low-sodium diet. A single dose of enalapril (0.5 mg/kg PO) was given to eight clinically healthy male Beagle dogs after a period where the dogs were fed a normal-sodium diet and low-sodium diet, respectively. Serum angiotensin-converting enzyme activity (ACE), plasma renin activity (PRA), plasma aldosterone concentration (PAC), and plasma atrial natriuretic peptide (ANP) concentration were measured during the following twenty-four hour period. The data indicate that enalapril induced a potent blockade of the renin-angiotensin system (RAS) for at least twenty-four hour. Specifically, enalapril during low-sodium diet elicited an exaggerated increase in PRA and a diminished decrease in ACE and ANP when compared to the results of the drug during normal-sodium diet. Long term controlled studies of enalapril in dogs with congestive heart failure (CHF) are warranted in order to determine the duration of action and optimal dose of enalapril.