Hypercoagulability in cats with cardiomyopathy

BACKGROUND: Arterial thromboembolism (ATE) is a common complication of feline cardiomyopathy; however, the pathogenesis of ATE is unknown. HYPOTHESIS: Systemic activation of the coagulation cascade (hypercoagulability) and endothelial injury promote ATE in cardiomyopathic cats. ANIMALS: Healthy cats (n = 30) and 3 groups of cardiomyopathic cats: Group (1) left atrial enlargement only (LAE [n = 11]), ie, left atrial to aortic ratio >1.4; Group (2) LAE with spontaneous echocardiographic contrast, atrial thrombi or both (SEC-T [n = 16]); and Group (3) acute ATE with LAE (n = 16). METHODS: Hypercoagulability was defined by 2 or more laboratory abnormalities reflecting coagulation factor excess (high fibrinogen concentration or Factor VIII coagulant activity), inhibitor deficiency (low antithrombin activity), or thrombin generation (high thrombin-antithrombin complex [TAT] and d-dimer concentrations). High von Willebrand factor antigen concentration (vWF : Ag) was considered a marker of endothelial injury. Data were analyzed using nonparametric statistics. RESULTS: The 3 groups of cats with cardiac disease had higher median fibrinogen concentrations than did the healthy cats. Criteria of hypercoagulability were found exclusively in cats with SEC-T (50%) and ATE (56%). Hypercoagulability was not associated with left atrial size or congestive heart failure (CHF). ATE cats had significantly higher median vWF : Ag concentration than did the other groups. CONCLUSION AND CLINICAL IMPORTANCE: Systemic hypercoagulability is evident in many cardiomyopathic cats, often without concurrent CHF or overt ATE. Hypercoagulabilty may represent a risk factor for ATE. High vWF : Ag in ATE cats was attributed to downstream endothelial injury from the occlusive thrombus.     

The effect of hydration status on the echocardiographic measurements of normal cats

BACKGROUND: Diagnosis of cardiomyopathy of cats is based on 2-dimensional (2D) echocardiography. However, circulating fluid volume largely determines diastolic cardiac chamber dimensions, and reduced diastolic volume in other species results in what has been called "pseudohypertrophy of the ventricular myocardium." HYPOTHESIS: Altered hydration produces changes on 2D echocardiography that may confound the diagnosis or severity assessment of cardiomyopathy of cats. ANIMALS: Ten normal colony-sourced mixed breed cats were included. METHODS: Cats were examined by echocardiography at baseline and at completion of 3 protocols (volume depletion and maintenance-rate and anesthetic-rate IV fluid administration) applied in randomized crossover design with a 6-7 day washout period. RESULTS: Volume depletion increased diastolic left ventricular interventricular septal (IVSd) and free wall diameter (4.5 +/- 0.4 to 5.8 +/- 0.6 mm; P < .001) with wall thickness exceeding 6 mm in 4 cats. Diastolic left ventricular internal diameter (LVIDd) decreased, and reduction in systolic left ventricular internal diameter (LVIDs) produced end-systolic cavity obliteration in 7 cats. Left-atrial-to-aortic-root ratio (LA: Ao, 1.4 +/- 0.2 to 1.2 +/- 0.1, P < .05) and left atrial area in diastole (LAAd) decreased with volume depletion. Maintenance-rate IV fluid administration increased LAAd and fractional shortening (FS%). Anesthetic-rate IV fluid administration increased LVIDd, FS%, LAAd, and LA:Ao ratios (to 1.7 +/- 0.1, P < .01), producing an LA: Ao ratio above normal limits in 6 cats. A systolic heart murmur developed with administration of fluid at maintenance (n = 1) and anesthetic rates (n = 6). CONCLUSIONS: Altered hydration status produces changes in the echocardiographic examination of normal cats that may lead to an erroneous diagnosis of cardiomyopathy or mask its presence. Hydration status should be considered during echocardiographic examination in cats.     

Circulating natriuretic peptides in cats with heart disease

BACKGROUND: Circulating natriuretic peptide concentrations are increased in cats with myocardial dysfunction. HYPOTHESIS: Serum N-terminal fragment of proatrial natriuretic peptide (NT-proANP) and NT-probrain natriuretic peptide (proBNP) concentrations may predict the presence of heart disease (HD) and congestive heart failure (CHF). A positive relationship is also predicted among natriuretic peptide (NP) concentrations, a noninvasive estimate of left ventricular filling pressure (E/E(a)), and an echocardiographic measure of left atrial (LA) size (LA/aortic diameter [Ao]). METHODS: Serum NP concentrations were measured in 28 healthy control and 50 study cats using sandwich enzyme immunoassays. The study group comprised cats, with HD but no CHF (HD - CHF, n = 17) and cats with CHF (HD + CHF, n = 33). The relationship among NP concentrations, LA size, and E/E(a) was examined. The ability of NP to distinguish control from study cats, and HD - CHF from HD + CHF cats, was explored using receiver operator curve analysis. RESULTS: NP concentrations were significantly lower in control than in study cats (P= .0001). The NT-proBNP concentrations were positively correlated with LA/Ao ratio (rho= 0.34; P= .02) and with E/E(a) ratio (rho= 0.68; P < .05). An NT-proBNP concentration of 49 fmol/mL gave a sensitivity and specificity of 100 and 89.3%, respectively, for correctly distinguishing 96.2% of control from study cats. Pairwise comparisons of the areas under the curve identified a statistically significant difference (P= .011) between NT-proANP and NT-proBNP to distinguish control from study cats. NT-proANP and NT-proBNP concentrations were significantly higher in HD + CHF cats than in HD - CHF cats (P= .0023 and .0001, respectively). CONCLUSIONS: Serum concentrations of NT-proANP and particularly NT-proBNP were different in healthy control cats, asymptomatic cats with HD, and cats with CHF, suggesting that measurement of NP concentrations may prove clinically useful as an initial screening test for cats with suspected cardiac disease.     

Quantification of left ventricular diastolic wall motion by Doppler tissue imaging in healthy cats and cats with cardiomyopathy

OBJECTIVE: To assess Doppler tissue imaging (DTI) for evaluating left ventricular diastolic wall motion in healthy cats and cats with cardiomyopathy. ANIMALS: 20 healthy cats, 9 cats with hypertrophic cardiomyopathy (HCM), and 9 cats with unclassified cardiomyopathy (UCM). PROCEDURE: A pulsed wave DTI sample gate was positioned at a subendocardial region of the left ventricular free wall in the short axis view and at the lateral mitral annulus in the apical 4-chamber view. Indices of diastolic wall motion were measured, including peak diastolic velocity (PDV), mean rate of acceleration and deceleration of the maximal diastolic waveform (MDWaccel and MDWdecel, respectively), and isovolumetric relaxation time (IVRT). RESULTS: The PDV of cats with HCM and 6 of 9 cats with UCM was significantly decreased, compared with that of healthy cats. In the 3 cats with UCM that had a PDV that was not different from healthy cats, MDWaccel and MDWdecel were greater, and IVRT was shorter than those of healthy cats. The IVRT in cats with HCM was longer than that of other cats. CONCLUSIONS AND CLINICAL RELEVANCE: Indices of diastolic function in cats with HCM, and in many cats with UCM, differed from those of healthy cats and were similar to those reported in humans with HCM and restrictive cardiomyopathy, respectively. However, the hemodynamic abnormality was not the same for all cats with UCM; some cats with an enlarged left atrium and a normal left ventricle (ie, UCM) had abnormal left ventricular wall motion consistent with restrictive cardiomyopathy while others did not.     

Echocardiography, electrocardiography, and radiography of cats with dilatation cardiomyopathy, hypertrophic cardiomyopathy, and hyperthyroidism

The echocardiographic, ECG, and radiographic findings of sequentially examined cats with dilatation cardiomyopathy (DCM, n = 7), hypertrophic cardiomyopathy (HCM, n = 8), and hyperthyroidism (HT, n = 20) were compared with those of healthy control cats (n = 11). Cats with DCM were easily differentiated from healthy cats by echocardiography and from cats with HCM and HT by a dilated left ventricle at end-diastole with a mean +/- SD of 2.20 +/- 0.36 cm, reduced fractional shortening (2.9% +/- 3.7%), reduced aortic amplitude (0.07 +/- 0.05 cm), reduced left ventricular wall amplitude (0.09 +/- 0.09 cm), and increased E-point septal separation (0.83 +/- 0.29 cm). The cats with HCM were most consistently recognized echocardiographically by increased left ventricular wall thickness at end-diastole (0.75 +/- 0.12 cm). Some cats with HT had abnormal echocardiograms with left ventricular wall hypertrophy. These cats could usually be differentiated from the cats with HCM because of normal or increased ventricular wall amplitude, aortic amplitude, or percentage of thickening of the left ventricular wall and interventricular septum. Left atrial enlargement (left atrial diameter greater than 1.57 cm or left atrium/aorta greater than 1.75) was commonly detected by the echocardiogram in cats with DCM, HCM, or HT. The echocardiogram was helpful in differentiating the type of cardiomyopathy (DCM, HCM, or HT) when plain thoracic radiographs indicated that cardiomegaly existed. The ECG may have indicated incorrectly that there was left ventricular enlargement in some cats with HT, and it did not indicate consistently that left ventricular enlargement existed when present in cats with DCM or HCM. The ECG was a poor indicator of left atrial enlargement in all cats.     

One-stage prothrombin time, activated partial thromboplastin time, thrombin time, fibrin degradation product concentration, and antithrombin activity in healthy adult alpacas

Background: Alpacas are increasingly presented to veterinarians for evaluation and care. Reports of alpaca reference intervals for one‐stage prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), concentration of fibrin degradation products (FDP), and antithrombin (AT) activities are scarce or nonexistent. Objective: The aim of this study was to determine values for blood coagulation times (PT, aPTT, and TT), FDP concentrations, and AT activities in healthy adult alpacas. Methods: Of blood samples collected from 35 clinically healthy adult alpacas via jugular venipuncture and placed into sodium citrate and FDP tubes, 29 samples were assayable for coagulation testing. PT, aPTT, and TT were determined by physical (mechanical) clot detection; AT activity was determined using a thrombin‐specific chromogenic substrate end‐point assay; and FDP concentrations were determined by the slide agglutination method. Results: Median values and ranges (minimum–maximum) were determined for PT (8.7 seconds, 6.6–11.2 seconds), aPTT (17.3 seconds, 11.9–22.5 seconds), TT (10.2 seconds, 5.4–16.0 seconds), and AT activity (123.3%, 104.8–144.2%). The mean concentration of FDP was <8 μg/mL. Conclusion: These values for coagulation times, FDP concentration, and AT activity will provide a useful starting point in the diagnostic evaluation of ill adult alpacas.     

Echocardiographic parameters in healthy young adult Sphynx cats

The objective of this retrospective study is to determine normal reference values for 2-Dimension (2D) and Motion-mode (M-mode) echocardiographic parameters in nonsedated healthy young adult Sphynx cats and to compare them to those of the domestic shorthair (DSH). 131 Sphynx cats underwent cardiac screening prior to breeding. The control group consisted of 30 healthy adult domestic cats. A complete cardiac ultrasound was performed on all cats using right parasternal long and short axis views. There were few echocardiographic parameters in the Sphynx that differed from those of the healthy DSH. Only the left atrial (LA) dimension in 2D and M-mode, the left atrial/aortic (LA/Ao) ratio and the internal dimension of the left ventricle in systole (LVIDs) measured with M-mode were different. In conclusion, although the heart of Sphynx cat can often have a particular 2-D echocardiographic appearance, the M-mode cardiac dimensions are similar to those of the DSH.     

Evaluation of plasma antithrombin activity and D-dimer concentration in populations of healthy cats, clinically ill cats, and cats with cardiomyopathy

BACKGROUND: Current coagulation tests lack sensitivity and detect disseminated intravascular coagulation (DIC) only when it is severe. Measurement of antithrombin (AT) activity and D-dimer concentration permits early diagnosis and more precise classification of coagulopathies in some species. OBJECTIVES: The objectives of this study were to validate and determine the diagnostic utility of a chromogenic AT assay and an immunoturbidimetric D-dimer assay for the diagnosis of DIC in cats. METHODS: Citrated plasma samples were collected from 30 healthy cats, 30 ill cats, and 13 cats with cardiomyopathy. Partial thromboplastin time, prothrombin time, fibrin(ogen) degradation products, platelet concentration, and erythrocyte morphology were determined on all samples to document the presence or the absence of DIC. AT activity and D-dimer concentration were then measured. RESULTS: The chromogenic AT assay was linear and precise. Mean AT activity was higher in ill cats and cats with cardiomyopathy compared with healthy cats, but the difference was only significant in ill cats (P = .003). Seven cats met the criteria for DIC. Of the cats with DIC, 2 had decreased AT activity, 1 had increased AT activity, and 4 had AT activities within normal limits. The immunoturbidimetric D-dimer assay did not appear to accurately measure feline D-dimer. CONCLUSIONS: The chromogenic AT assay appeared to measure AT in cats but was not useful for the diagnosis of DIC. AT may be an acute phase reactant in cats. The immunoturbidimetric D-dimer assay was not useful for the diagnosis of DIC in cats.     

Platelet function in clinically healthy cats and cats with hypertrophic cardiomyopathy: analysis using the Platelet Function Analyzer‐100

Background: There is currently no simple analytical tool for the evaluation of hypercoagulability in cats. The Platelet Function Analyzer‐100^® (PFA‐100; Dade Behring Inc., Deerfield, IL, USA) is a bench‐top machine that evaluates platelet function by measuring closure time (CT) in citrated whole blood under high shear conditions. We hypothesized that cats with hypertrophic cardiomyopathy (HCM) have up‐regulated platelet function, which shortens their CT and increases their risk for thromboembolic events. Objectives: The goals of this study were to: (1) establish a feline reference interval for CT using the PFA‐100, (2) measure CT in blood from cats with HCM, and (3) determine if there is a measurable difference between the CT of healthy cats compared with cats with HCM. Methods: Citrated blood samples from 42 clinically healthy cats and 30 cats with HCM were analyzed according to manufacturer's specifications. CT was measured in triplicate and the mean value was used for analysis. Transformed data were compared between clinically healthy cats and cats with HCM using a Student's t‐test, and among cats with mild, moderate, or severe HCM using ANOVA. Results: The median CT of clinically healthy cats was 64 seconds (range 43–176 seconds). The median CT of cats with HCM was 74 seconds (range 48–197 seconds). There was no significant difference in CT between cats with HCM and clinically healthy cats. There also were no significant differences in cats with mild, moderate, or severe HCM. Conclusions: A feline reference interval for PFA‐100 CT will be useful in future studies of platelet function in cats. Cats with HCM do not have shorter CTs when compared with clinically healthy cats.     

Transient Myocardial Thickening in Cats Associated with Heart Failure

Background

Cats with hypertrophic cardiomyopathy (HCM) and congestive heart failure (CHF) can have resolution of both left ventricular hypertrophy and CHF.

Objectives

To describe the clinical characteristics of cats with transient myocardial thickening (TMT) and CHF compared with a control population of cats without resolution of HCM.

Animals

A total of 21 cats with TMT, 21 cats with HCM.

Methods

Retrospective study. Clinical records at 4 veterinary centers were searched for TMT cases and a control group of cats with HCM and CHF. TMT was defined as initial maximal left ventricular wall thickness (LVWT) ≥6 mm with left‐sided CHF, with subsequent resolution of CHF, reduction in left atrium/aorta (LA/Ao), and LVWT<5.5 mm. HCM was defined as persistent LVWT ≥6 mm.

Results

Cats with TMT were younger (2 [0.4–11.4] years) than cats with HCM (8 [1.6–14] years) (P < 0.0001), and antecedent events were more common (15/21 versus 6/21, respectively) (P = 0.01). In cats with TMT, LVWT normalized from 6.8 [6.0–9.7] mm to 4.8 [2.8–5.3] mm and LA/Ao decreased from 1.8 [1.6–2.3] to 1.45 [1.2–1.7] after a mean interval of 3.3 (95% CI: 1.8–4.7) months. CHF recurred in 1 of 21 TMT and 15 of 21 cats with HCM. Cardiac treatment was discontinued in 20 of 21 cats with TMT and 0 of 21 HCM cats. All cats with TMT survived, whereas 8 of 19 cats with HCM died during the study period.

Conclusions and Clinical Importance

TMT occurs in younger cats, and antecedent events are common. The prognosis is better in cats with CHF associated with TMT than HCM.     

N-terminal atrial natriuretic peptide immunoreactivity in plasma of cats with hypertrophic cardiomyopathy

Atrial natriuretic peptide (ANP) is an important regulator of fluid homeostasis and vascular tone. We sought to compare N-terminal ANP immunoreactivity (ANP-IR) in plasma from cats with and without hypertrophic cardiomyopathy (HCM). Secondarily, we evaluated relationships between ANP-IR and echocardiographical variables in cats with HCM and healthy cats. Venous blood samples were obtained from 17 cats with HCM and from 19 healthy cats. Plasma ANP-IR concentration was determined by an enzyme-linked immunoassay. Two cats with HCM had clinical evidence of congestive heart failure; the remainder had subclinical disease. Plasma ANP-IR concentration was higher in cats with HCM (3,808 +/- 1,406 fmol/L, mean +/- SD) than in control cats (3,079 +/- 1,233 fmol/L), but this difference was not statistically significant (P = .11; 95% confidence interval [CI] = -166 to 1,622). There was a significant, but modest correlation between plasma ANP-IR concentration and left ventricular posterior wall thickness (r = 0.42; P = .01). Additionally, plasma ANP-IR concentration was weakly correlated with left atrial size (r = 0.35; P = .03). A linear regression model was developed to further explore these relationships. Atrial size and wall thickness were included in the model; the 2 explanatory variables had an interactive effect on plasma ANP-IR concentration (R2 = 0.27; P = .02). There was no appreciable correlation between plasma ANP-IR concentration and any other echocardiographical variable. In a population that included cats with subclinical disease, those with HCM did not have significantly higher plasma ANP-IR concentration than did healthy cats. An exploratory multivariable regression analysis suggested a linear relationship between ANP-IR concentration and atrial size, wall thickness, and their interaction.     

Disseminated intravascular coagulation in cats

The purpose of this study was to describe the clinical characteristics of cats with disseminated intravascular coagulation (DIC), including associated diseases and hemostatic abnormalities, and to identify risk factors for death and treatments that potentially altered outcome. Medical records for cats with DIC from 1990-2004 were evaluated retrospectively. Inclusion criteria were the presence of an underlying disorder associated with DIC and either postmortem examination findings of intravascular fibrin deposition or thrombosis, or both of 2 or more organs or coagulation profiles that meet 3 of 5 criteria: prolonged prothrombin time (PT), activated partial thromboplastin time (aPTT), presence of fibrin degradation products (FDP), low plasma fibrinogen (FIB) concentration, and thrombocytopenia (<160,000 platelets/microL). Signalment, historical data, clinical findings, clinicopathologic data, underlying disorders, management, and outcome were recorded. Forty-six cats fulfilled the criteria for DIC. Cats ranged in age from 7 weeks to 17 years (median, 9 years). Hemorrhage was noted in 7 of 46 cats (15%). Three of 46 cats (7%) survived, whereas 43 of 46 (93%) died or were euthanized. The most common underlying disorders were lymphoma, other forms of neoplasia, pancreatitis, and sepsis. There was no association detected between outcome and signalment; underlying disease; hemorrhage; abnormalities in aPTT, FIB, FDPs, platelet count; transfusion of blood products; and heparin therapy. However, the median PT of nonsurvivors was more prolonged than in survivors (P < .005). DIC in cats can result from a variety of neoplastic, infectious, and inflammatory disorders, and is associated with a high case fatality rate.     

Measurement of M-mode echocardiographic parameters in healthy adult Maine Coon cats

OBJECTIVE: To determine reference values for M-mode echocardiographic parameters in nonsedated healthy adult Maine Coon cats and compare those values with data reported for nonsedated healthy adult domestic cats. DESIGN: Prospective study. ANIMALS: 105 healthy adult Maine Coon cats. PROCEDURE: Over a 3-year period, M-mode echocardiographic examinations (involving a standard right parasternal transthoracic technique) were performed on Maine Coon cats as part of prebreeding evaluations; values of M-mode parameters in healthy individuals were collected, and mean values were calculated for comparison with those reported for healthy adult domestic cats. RESULTS: The mean +/- SD weight of Maine Coon cats was significantly greater than that of domestic cats. Mean values of left ventricular internal dimension at end diastole and end systole (LVIDd and LVIDs, respectively), interventricular septal thickness at end systole (IVSs), left ventricular posterior wall thickness at end systole (LVPWs), left atrial dimension at end systole (LADs), and aortic root dimension (Ao) in Maine Coon cats differed significantly from values in healthy domestic cats. The greatest differences detected between the 2 groups involved values of LVIDd, LADs, and Ao. Linear regression analysis revealed a weak but significant correlation between weight and each of LVIDd, LVPWs, IVSs, Ao, LADs, and left ventricular posterior wall thickness at end diastole. CONCLUSIONS AND CLINICAL RELEVANCE: Values of several M-mode echocardiographic parameters in Maine Coon cats differ from those reported for domestic cats; these differences should be considered during interpretation of echocardiographic findings to distinguish between cardiac health and disease in this breed.     

Measurements of plasma endothelin immunoreactivity in healthy cats and cats with cardiomyopathy

Plasma concentrations of endothelin-1 (ET-1), the most potent endogenous pressor substance discovered to date, are abnormally high in humans with congestive heart failure (CHF), and they correlate with the degree of functional impairment. We sought first to validate a human sandwich ELISA kit that targets that portion of the amino acid sequence that is identical in cats. The assay demonstrated linearity (R2 = .9968) and parallelism (P = .5339), recovery of spiked human ET-1 in cat plasma averaged 98.7%, and intraassay precision had a coefficient of variation <10%. We subsequently determined ET-1 immunoreactivity in healthy cats and in cats with myocardial disease with and without CHF, systemic thromboembolism (STE), or both. Plasma ET-1 immunoreactivity was measured in 12 healthy cats and in 28 cats with primary myocardial disease, including hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), or restrictive or unclassified cardiomyopathy (RCM and UCM), respectively. Plasma ET mean (95% CI) concentrations were 0.777 (0.6536-0.924) fmol/mL in the control cats, 1.427 (0.922-2.209) fmol/mL in 12 cats with cardiomyopathy (HCM = 11, RCM/UCM = 1) but without CHF or evidence of STE, and 2.360 (1.666-3.343) fmol/mL in 16 cats with cardiomyopathy (HCM = 8, RCM/UCM = 7, DCM = 1) and CHF (n = 15) or STE (n = 4). Plasma immunoreactivity of ET-1 was significantly higher in cats with myocardial disease without CHF/STE versus normal cats (P < .05) and in cats with myocardial disease with CHF/STE versus normal cats (P < .001).     

Evaluation of plasma C-terminal atrial natriuretic peptide in healthy cats and cats with heart disease

BACKGROUND: The clinical implications of evaluating C-terminal atrial natriuretic peptide (ANP) concentration in cats are still controversial. HYPOTHESIS: The objective of this study was to investigate the relationship between plasma C-terminal ANP concentration and left atrial pressure (LAP) in healthy cats with volume overload (study 1), and to compare plasma C-terminal ANP in normal cats and cats with cardiomyopathy (study 2). ANIMALS: Five healthy adult cats were used in study 1, and clinically healthy cats (n=8) and cats with cardiomyopathy (n=14) were used in study 2. METHODS: In study 1, cats were anesthetized and given acetated Ringer's solution (100 mL/kg/h for 60 minute) via the cephalic vein. Hemodynamic measurements and blood samples, collected from the jugular vein, were performed at 10-min intervals. In study 2, blood samples from normal cats and cats with cardiomyopathy were collected from the cephalic vein. The plasma C-terminal ANP concentration was determined by radioimmunoassay for human alpha-ANP. RESULTS: In study 1, volume overload significantly increased the C-terminal ANP concentration and LAP from baseline. The C-terminal ANP concentration was strongly correlated with the mean LAP. In study 2, age, E wave velocity, and the ratios of the left atrium to aorta were significantly higher in the cats with cardiomyopathy compared with the normal cats. The C-terminal ANP concentration was significantly higher in the cats with cardiomyopathy compared with the normal cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Our results suggest that the measurement of plasma C-terminal ANP in cats may provide additional information for the diagnosis of heart disease.     

Coagulation profiles of healthy Andalusian donkeys are different than those of healthy horses

Background: Coagulation disorders are frequently diagnosed, especially in hospitalized equidae, and result in increased morbidity and mortality. However, hemostatic reference intervals have not been established for donkeys yet. Objectives: To determine whether the most common coagulation parameters used in equine practice are different between healthy donkeys and horses. Animals: Thirty‐eight healthy donkeys and 29 healthy horses. Methods: Blood samples were collected to assess both coagulation and fibrinolytic systems by determination of platelet count, fibrinogen concentration, clotting times (prothrombin time [PT] and activated partial thromboplastin time [aPTT]), fibrin degradation products (FDP) and D‐Dimer concentrations. Results: PT and aPTT in donkeys were significantly (P < .05) shorter than those of horses. In contrast, FDP and D‐Dimer concentrations were significantly (P < .05) higher in donkeys than in horses. Conclusions and Clinical Importance: The coagulation parameters most commonly determined in equine practice are different in donkeys compared with horses. Thus, the use of normal reference ranges reported previously for healthy horses in donkeys might lead to a misdiagnosis of coagulopathy in healthy donkeys, and unnecessary treatments in sick donkeys. This is the first report of normal coagulation profile results in donkeys, and further studies are warranted to elucidate the physiological mechanisms of the differences observed between donkeys and horses.     

Comparisons of morphometric measurements and serum insulin-like growth factor concentration in healthy cats and cats with hypertrophic cardiomyopathy

OBJECTIVE: To compare morphometric measurements and serum insulin-like growth factor (IGF-1) concentration in cats with and without hypertrophic cardiomyopathy (HCM), and assess the hypothesis that cats with HCM have larger body size and skeletal features and higher serum IGF-1 concentrations than healthy cats. ANIMALS: 25 cats with HCM and 22 healthy control cats. PROCEDURES: Physical examination and echocardiography were performed to classify cats into the HCM and control groups. Data collected from each cat included diet history, body weight, body condition score, lengths of the humerus and 4th and 12th thoracic vertebrae, heart size, head length and width, and abdominal circumferences. Comparisons of these variables were made between groups. RESULTS: Body condition score in HCM-affected and control cats did not differ significantly. However, median head width; lengths of the head, 4th and 12th thoracic vertebrae, and humerus; and body weight in the HCM-affected group were significantly greater than values in the control group. Median serum concentration of IGF-1 was not significantly different between groups. CONCLUSIONS AND CLINICAL RELEVANCE: These data suggested that among the study cats, those with HCM were skeletally larger, but not more obese, than healthy cats. Whether this was attributable to differences in early growth or other causes requires additional investigation.     

Assessment of left ventricular longitudinal function in cats with subclinical hypertrophic cardiomyopathy using tissue Doppler imaging and speckle tracking echocardiography

Hypertrophic cardiomyopathy (HCM) in cats is characterized by concentric left ventricular (LV) hypertrophy and both diastolic and systolic dysfunction. Although impaired cardiac function detected by tissue Doppler imaging (TDI) in cats with HCM was previously reported, reference ranges of TDI in normal cats and cats with HCM have been reported as widely variable. Two-dimensional speckle tracking echocardiography (STE) was useful for assessment of cardiac function in human patients with HCM, but clinical utility was not known in cats. The aim of this study was to assess global and segmental LV myocardial function using STE in cats with HCM whose TDI variables were within the reference range. A total of 35 cats of different breeds were enrolled in this study. The HCM group (n=22) was cats diagnosed as HCM without left atrial enlargement and with normal TDI measurements. HCM cats were further divided into a segmental hypertrophy (S-HCM) group and a diffuse hypertrophy (D-HCM) group. The control group consisted of 13 clinically healthy cats. No cats in any group showed any clinical symptoms. Conventional echocardiography, TDI, and global and segmental STE indices were evaluated and compared between groups. Only the longitudinal strain rate during early diastole was significantly decreased in both HCM groups, even in all segments including those without hypertrophy in S-HCM group. This study suggests that STE parameters are the more sensitive variables compared with conventional TDI parameters to detect early myocardial diastolic dysfunction in cats with HCM.     

Natural history of hypertrophic cardiomyopathy and aortic thromboembolism in a family of domestic shorthair cats

A feline domestic shorthair queen and her 3 offspring were all diagnosed with asymptomatic hypertrophic cardiomyopathy (HCM). The family has been followed for 13 years, and 3 cats have died of aortic thromboembolism (ATE). This communication documents the long-term progression of HCM in these cats that presented with mild left ventricular hypertrophy and hyperdynamic systolic ventricular function, developed progressive left atrial enlargement, and eventually resulted in hypodynamic left ventricular systolic function with relative left ventricular chamber dilation at the time of ATE.     

Changes in the coagulation parameters in dogs with protein-losing enteropathy between before and after treatment

Protein-losing enteropathy (PLE) is known to induce hypercoagulability and resultant thromboembolism in dogs. We hypothesized that hypercoagulability would improve if remission was obtained in dogs with PLE after treatment. This study aimed to evaluate the changes in the coagulation parameters after treatment in dogs diagnosed with PLE. As coagulation parameters, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, thrombin-antithrombin complex (TAT), D-dimer, and antithrombin (AT) were measured. In addition to these parameters, rotational thromboelastometry (ROTEM), which evaluates the comprehensive coagulation and fibrinolysis reactions of whole blood, was conducted and the data of clotting time (CT), clot formation time (CFT), α angle (α), maximum clot firmness (MCF) and lysis index at 60 min (LI60) were obtained. Eleven of the 14 dogs diagnosed with PLE were classified as responders to the treatment based on the changes in their plasma albumin (ALB) concentration after treatment. Significant increase in CFT and decrease of α and MCF indicating the resolution of hypercoagulability were found after treatment in responder dogs; however, there was no significant change in the coagulation and fibrinolysis parameters other than those measured by ROTEM. This study demonstrated that the hypercoagulability detected by ROTEM was significantly improved after treatment in dogs with PLE.