Evaluation of circulating amino terminal-pro-B-type natriuretic peptide concentration in dogs with respiratory distress attributable to congestive heart failure or primary pulmonary disease

OBJECTIVE: To evaluate assessment of circulating amino terminal-pro-B-type natriuretic peptide (NT-proBNP) concentration as a means to discriminate between congestive heart failure and primary pulmonary disease in dogs. DESIGN: Prospective case series. ANIMALS: 46 dogs with signs of respiratory distress or coughing. PROCEDURES: All dogs underwent physical and thoracic radiographic examinations. Dogs with evidence of heart disease (eg, murmur, arrhythmia, or large cardiac silhouette detected by radiography) also underwent echocardiography. Dogs with no evidence of heart disease or failure were included if they underwent bronchoalveolar lavage (with cytologic examination and bacterial culture of the lavage fluid). Blood samples for NT-proBNP assay were obtained within 12 hours of the diagnosis of heart failure or prior to bronchoalveolar lavage in dogs with primary pulmonary disease. Circulating concentrations of NT-proBNP were compared between groups and correlated with radiographic and echocardiographic measures of cardiac size. RESULTS: Congestive heart failure and primary pulmonary disease were diagnosed in 25 and 21 dogs, respectively. Dogs with congestive heart failure had significantly higher median serum or plasma NT-proBNP concentration (2,554 pmol/L; interquartile [25% to 75%] range, 1,651.5 to 3,475.5 pmol/L) than dogs with primary pulmonary disease (357 pmol/L; interquartile range, 192.5 to 565.5 pmol/L). Radiographic vertebral heart score and echocardiographic left atrial-to-aortic diameter ratio were not correlated with NT-proBNP concentration. Left ventricular end-diastolic diameter (measured echocardiographically) and NT-proBNP concentration were weakly correlated. CONCLUSIONS AND CLINICAL RELEVANCE: Serum or plasma NT-proBNP concentration assessment may be useful for discrimination of congestive heart failure from primary pulmonary disease in dogs with respiratory distress or cough.     

Effect of azotemia on serum N-terminal proBNP concentration in dogs with normal cardiac function: A pilot study

ObjectivesTo evaluate amino-terminal pro-B type natriuretic peptide (NT-proBNP) concentration in dogs with renal dysfunction and normal cardiac structure and function.AnimalsEight dogs with renal disease, 23 healthy control dogs.MethodsSerum NT-proBNP concentration was measured in healthy dogs and dogs with renal disease using an ELISA validated for use in dogs. Affected dogs were eligible for inclusion if renal dysfunction was diagnosed based on urinalysis and serum chemistry, and if they were free of cardiovascular disease based on physical exam, systolic blood pressure, and echocardiography.ResultsThe geometric mean serum NT-proBNP concentration was significantly higher in dogs with renal disease (617 pmol/L; 95% CI, 260–1467 pmol/L) than in healthy control dogs (261 pmol/L; 95% CI, 225–303 pmol/L; P = 0.0014). There was a modest positive correlation between NT-proBNP and BUN and creatinine. Median NT-proBNP concentration was not significantly different between groups when indexed to BUN (median NT-proBNP:BUN ratio; renal, 14.2, IQR, 3.93–17.7 vs. control, 16.3, IQR, 9.94–21.2; P = 0.29) or creatinine (median NT-proBNP:creatinine ratio; renal, 204, IQR, 72.6–448 vs. control, 227, IQR, 179–308; P = 0.67).ConclusionDogs with renal disease had significantly higher mean serum concentration of NT-proBNP than control dogs. Renal function should be considered when interpreting NT-proBNP results as concentrations may be falsely elevated in dogs with renal dysfunction and normal cardiac function. The effect of renal disease was lessened by indexing NT-proBNP to BUN or creatinine. Future studies in dogs with both renal and heart disease are warranted.     

Cardiac troponin I: evaluation I of a biomarker for the diagnosis of heart disease in the dog

OBJECTIVES: To assess the value of measuring blood levels of the myocardial protein cardiac troponin I (cTnl) in the diagnosis of congenital and acquired heart disease in the dog and in the evaluation of the severity of heart failure. METHODS: Serum samples obtained from healthy dogs (n = 26) and from dogs diagnosed with a variety of congenital and acquired heart conditions (n = 35) were assayed for cTnl concentration using an automated immunoassay method. Results were also analysed according to the degree of heart failure as assessed using the International Small Animal Cardiac Health Council's scheme. RESULTS: Healthy dogs had very low or undetectable blood cTnl levels, as did dogs with congenital heart disease. However, cTnl levels were significantly elevated in dogs with acquired mitral valve disease, dilated cardiomyopathy and pericardial effusion. Blood cTnl levels also varied with severity of heart failure. CLINICAL SIGNIFICANCE: Measurement of blood cTnl levels may be a useful aid in the diagnosis of dogs with suspected heart disease and in indicating the severity of heart failure.     

The diagnostic accuracy of different natriuretic peptides in the investigation of canine cardiac disease

OBJECTIVES: We aimed to validate and determine the accuracy of a new sandwich ELISA for canine N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the discrimination of canine patients with cardiac disease from those with respiratory disease and to determine the effect of confounding variables on NT-proBNP concentrations. METHODS: Validation studies for the new assay were undertaken. Concentrations of N-terminal atrial natriuretic peptide (NT-proANP) and NT-proBNP in both ethylenediaminetetraacetic acid (EDTA) plasma and serum were estimated in samples from 77 dogs at a laboratory blinded to the clinical status of the patient. The diagnostic accuracy of the each sample type and test was evaluated using receiver operating characteristic curves. The effect of age, gender and indicators of renal function was evaluated using a multivariate regression analysis. RESULTS: Concentrations of NT-proBNP in both serum and plasma accurately discriminated dogs with respiratory disease from those with cardiac disease, with an optimum cut-off concentration of 210 pmol/l. NT-proBNP concentrations were unaffected by sample type. Increasing creatinine concentration is associated with increasing concentration of NT-proBNP. Age and gender were not found to have significant effects on natriuretic peptide concentrations in this population. CLINICAL SIGNIFICANCE: Canine NT-proBNP appears to be a useful marker of the presence of cardiac disease, although concentrations must be interpreted in the light of the patient's renal function.     

Serum Cardiac Troponin I Concentration in Dogs with Precapillary and Postcapillary Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a disease condition leading to right-sided cardiac hypertrophy and, eventually, right-sided heart failure. Cardiac troponin I (cTnI) is a circulating biomarker of cardiac damage.
Hypothesis: Myocardial damage can occur in dogs with precapillary and postcapillary PH.
Animals: One hundred and thirty-three dogs were examined: 26 healthy controls, 42 dogs with mitral valve disease (MVD) without PH, 48 dogs with pulmonary hypertension associated with mitral valve disease (PH-MVD), and 17 dogs with precapillary PH.
Methods: Prospective, observational study. Serum cTnI concentration was measured with a commercially available immunoassay and results were compared between groups.
Results: Median cTnI was 0.10 ng/mL (range 0.10–0.17 ng/mL) in healthy dogs. Compared with the healthy population, median serum cTnI concentration was increased in dogs with precapillary PH (0.25 ng/mL; range 0.10–1.9 ng/mL; P < .001) and in dogs with PH-MVD (0.21 ng/mL; range 0.10–2.10 ng/mL; P < .001). Median serum cTnI concentration of dogs with MVD (0.12 ng/mL; range 0.10–1.00 ng/mL) was not significantly different compared with control group and dogs with PH-MVD. In dogs with MVD and PH-MVD, only the subgroup with decompensated PH-MVD had significantly higher cTnI concentration compared with dogs with compensated MVD and PH-MVD. Serum cTnI concentration showed significant modest positive correlations with the calculated pulmonary artery systolic pressure in dogs with PH and some echocardiographic indices in dogs with MVD and PH-MVD.
Conclusions and Clinical Importance: Serum cTnI is high in dogs with either precapillary and postcapillary PH. Myocardial damage in dogs with postcapillary PH is likely the consequence of increased severity of MVD.     

Association of Plasma N-Terminal Pro-B-Type Natriuretic Peptide Concentration with Mitral Regurgitation Severity and Outcome in Dogs with Asymptomatic Degenerative Mitral Valve Disease

Background: The clinical outcome of dogs affected by degenerative mitral valve disease (MVD) without overt clinical signs is still poorly defined, and criteria for identification of animals that are at a higher risk of early decompensation have not yet been determined.
Hypothesis: N-terminal pro-B-type natriuretic peptide plasma concentration (NT-proBNP) is correlated with mitral regurgitation (MR) severity and can predict disease progression in dogs with asymptomatic MVD.
Animals: Seventy-two dogs with asymptomatic MVD, with or without heart enlargement (International Small Animal Cardiac Health Council: ISACHC classes 1a and 1b), and a control group of 22 dogs were prospectively recruited.
Methods: Severity of MR was quantitatively assessed from the regurgitation fraction (RF) by the proximal isovelocity surface area method. Consequences of MR were evaluated from measurements of the left atrium/aorta ratio (LA/Ao), fractional shortening (FS), end-diastolic and end-systolic left ventricular volumes indexed to body surface area (EDVI and ESVI). The relevance of these echo-Doppler indices and NT-proBNP for prediction of outcome at 12 months was studied.
Results: A significant correlation was found between NT-proBNP and RF, LA/Ao, FS, and EDVI ( P < .05). NT-proBNP was higher in dogs with MVD (ISACHC classes 1a and 1b) compared with the control group ( P = .025 and < .001, respectively). The difference was not significant when only dogs from ISACHC class 1a with RF < 30% were considered. Lastly, NT-proBNP was higher in dogs that underwent MVD decompensation at 12 months ( P < .05).
Conclusions and Clinical Importance: NT-proBNP is correlated with MVD severity and prognosis in dogs with asymptomatic MVD.     

Plasma N-terminal pro-B-type natriuretic peptide concentration helps to predict survival in dogs with symptomatic degenerative mitral valve disease regardless of and in combination with the initial clinical status at admission

Objectives

Although mitral valve disease (MVD) is the most common canine heart disease, readily available prognostic markers of the disease are still lacking. The aim of this study was to evaluate the comparative ability of N-terminal pro-B-type natriuretic peptide plasma concentration (NT-proBNP) and various echocardiographic variables to predict outcome in dogs with MVD.

Animals, materials and methods

Seventy-four dogs with ISACHC classes 2 and 3 MVD (Groups A and B, respectively) were prospectively recruited. NT-proBNP and several echo-Doppler variables at inclusion were compared as predictors of outcome at 6 months in 54/74 dogs.

Results

NT-proBNP was significantly higher in Group B than in Group A (P < 0.0001), and was the only tested variable significantly different between survivor and non-survivor dogs in both groups (P < 0.05). In the whole canine population, a threshold of 1500 pmol/L could discriminate survivor from non-survivor dogs with a sensitivity and specificity of 80% and 73%, respectively. When combining ISACHC class with NT-proBNP levels, a cut-off of 1265 pmol/L was predictive of survival in Group A, whereas the cut-off was 2700 pmol/L for Group B.

Conclusions

NT-proBNP is correlated with MVD severity and could be used in combination with clinical status to predict cardiac outcome.     

Serum total thyroxine, total triiodothyronine, free thyroxine, and thyrotropin concentrations in dogs with nonthyroidal disease

OBJECTIVE: To determine whether nonthyroidal disease of various causes and severity is associated with abnormalities in baseline serum concentrations of total thyroxine (T4), triiodothyronine (T3), free T4, or thyrotropin (thyroid-stimulating hormone [TSH]) in dogs believed to be euthyroid. DESIGN: Case-control study. ANIMALS: 223 dogs with confirmed nonthyroidal diseases and presumptive normal thyroid function, and 150 clinically normal dogs. PROCEDURE: Serum total T4, total T3, free T4, and TSH concentrations were measured in dogs with confirmed nonthyroidal disease. Reference ranges for hormone concentrations were established on the basis of results from 150 clinically normal dogs. RESULTS: In dogs with nonthyroidal disease, median serum concentrations of total T4, total T3, and free T4 were significantly lower than those in clinically normal dogs. Median serum TSH concentration in sick dogs was significantly greater than that of clinically normal dogs. When stratified by severity of disease (ie, mild, moderate, and severe), dogs with severe disease had low serum concentrations of total T4, total T3, or free T4 more commonly than did dogs with mild disease. In contrast, serum TSH concentrations were more likely to remain within the reference range regardless of severity of disease. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that serum total T4, free T4, and total T3 concentrations may be low (ie, in the hypothyroid range) in dogs with moderate to severe nonthyroidal disease. Serum TSH concentrations are more likely to remain within the reference range in sick dogs.     

Brain-natriuretic peptide and cyclic guanosine monophosphate as biomarkers of myxomatous mitral valve disease in dogs

Elevations in the plasma concentrations of natriuretic peptides correlate with increased severity of myxomatous mitral valve disease (MMVD) in dogs. This study correlates the severity of MMVD with the plasma concentrations of the biomarkers N-terminal fragment of the pro-brain-natriuretic peptide (NT-proBNP) and its second messenger, cyclic guanosine monophosphate (cGMP). Furthermore, the l-arginine:asymmetric dimethylarginine (ADMA) ratio was measured as an index of nitric oxide availability. The study included 75 dogs sub-divided into five groups based on severity of MMVD as assessed by clinical examination and echocardiography.Plasma NT-proBNP and cGMP concentrations increased with increasing valve dysfunction and were significantly elevated in dogs with heart failure. The cGMP:NT-proBNP ratio decreased significantly in dogs with heart failure, suggesting the development of natriuretic peptide resistance. Although the l-arginine:ADMA ratio decreased with increasingly severe MMVD, this was largely due to the older age of the dogs with heart failure.     

Serum concentration of some acute phase proteins in naturally occurring canine babesiosis: a preliminary study

BACKGROUND: Serum concentrations of acute phase proteins can provide valuable diagnostic information in the detection, prognosis, or monitoring of disease. Information available on the acute phase response in naturally occurring canine babesiosis is limited. OBJECTIVE: The purpose of this investigation was to retrospectively evaluate serum concentrations of haptoglobin, C-reactive protein, and ceruloplasmin in dogs naturally infected with Babesia canis. METHODS: Haptoglobin, C-reactive protein, and ceruloplasmin concentrations were measured in serum samples from dogs with uncomplicated (n = 6) and complicated (n = 1) babesiosis and compared with 6 healthy dogs. RESULTS: Serum C-reactive protein and ceruloplasmin concentrations were significantly higher in dogs with babesiosis; however, serum haptoglobin concentration was significantly lower compared with control dogs (P <.01). CONCLUSIONS: Results of this study suggest that acute phase protein concentrations could be beneficial in the diagnosis and determination of the severity of babesiosis in dogs.     

Serum nitrate and nitrite in dogs with spontaneous cardiac disease

The purpose of this study was to determine whether nitric oxide (NO) concentrations are high in dogs with chronic valvular disease (CVD) and dilated cardiomyopathy (DCM) compared to healthy controls and to determine whether NO concentrations are correlated with type of cardiac disease, disease severity, medical therapy, or serum tumor necrosis factor (TNF) and interleukin-1 (IL-1). Blood was collected from 32 dogs with DCM, from 10 dogs with CVD, and from 10 healthy controls. Indirect determination of NO concentrations was performed by a commercial photoabsorbance assay that uses a Greiss reagent to measure the concentration of nitrite and nitrate (NN), end products of NO metabolism. TNF and IL-1 activities were measured by bioassay. Mean NN concentrations were significantly higher in dogs with heart disease (median, 4.57 microM; range, 0.00-31.05 microM) than in controls (median, 0.00 microM; range, 0.00-6.16 microM; P = .04). NN concentrations in dogs with cardiac disease were not correlated with type or severity of cardiac disease, medication type, or TNF and IL-1 concentrations. NN concentrations were inversely correlated with fractional shortening. The results of this study suggest that metabolites of NO are increased in some dogs with cardiac disease, but these increases appear to be independent of disease severity, TNF and IL-1 concentrations, and type of pharmacologic intervention.     

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.     

Matrix metalloproteinase-9 activity in the cerebrospinal fluid and serum of dogs with acute spinal cord trauma from intervertebral disk disease

OBJECTIVE: To detect matrix metalloproteinase (MMP)-9 in serum and CSF and determine relationships between MMP activity and severity of disease, duration of clinical signs, and duration of hospitalization in dogs with acute intervertebral disk disease (IVDD). ANIMALS: 35 dogs with acute IVDD and 8 clinically normal control dogs. PROCEDURE: CSF and serum were collected from affected and control dogs. Zymography was used to detect MMP-9. RESULTS: Activity of MMP-9 in CSF was detected in 6 of 35 dogs with IVDD; activity was significantly more common in dogs with duration of signs < 24 hours. Paraplegic dogs were more likely to have MMP-9 activity in the CSF than non-paraplegic dogs. No significant difference in hospitalization time was detected in dogs with IVDD between those with and without activity of MMP-9 in the CSF. Serum MMP-9 was detected more frequently in dogs with IVDD than in control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Data were consistent with results of experimental rodent spinal cord injury studies that indicate that MMP-9 is expressed early during secondary injury.     

Comparison of N-terminal pro-atrial natriuretic peptide and three cardiac biomarkers for discriminatory ability of clinical stage in dogs with myxomatous mitral valve disease

Plasma N-terminal pro-atrial natriuretic peptide (NT-proANP) concentration increases with progression of myxomatous mitral valve disease (MMVD) in dogs. This multicentre, prospective study compared plasma NT-proANP, N-terminal pro-brain natriuretic peptide (NT-proBNP), ANP, and cardiac troponin I (cTnI) concentrations in dogs with MMVD for their characteristics and discriminatory ability to detect cardiac dilatation and congestive heart failure (CHF). Thirty-six healthy dogs and 69 dogs with MMVD were included. Clinical variables were obtained via physical examination, thoracic radiography, and echocardiography. The discriminatory ability of each cardiac biomarker (CB) to determine the presence or absence of cardiac dilatation (event 1) and CHF (event 2) was evaluated using the receiver operating characteristic curves. Plasma NT-proANP, NT-proBNP, and ANP concentrations showed a significant association with the left atrium/aorta ratio (P<0.01). The area under the curve of plasma NT-proANP and NT-proBNP concentrations were 0.72 and 0.75, respectively in event1 and 0.72 and 0.76, respectively in event2. Plasma NT-proANP and NT-proBNP concentrations showed sensitivity 80.0 and 80.0%; specificity 67.6 and 64.7% in event1 (cutoff value; 8,497.81 pg/ml and 1,453.00 pmol/l, respectively) and sensitivity 85.7 and 81.0%; specificity 60.4 and 64.6% in event2 (cutoff value; 8,684.33 pg/ml and 1,772.00 pmol/l, respectively). In dogs with MMVD, plasma NT-proANP, NT-proBNP, and ANP concentrations increase with left atrial enlargement. Particularly, plasma NT-proANP and NT-proBNP concentrations appeared to be equally useful in the discriminatory ability to detect cardiac dilatation and CHF.     

Prediction of first onset of congestive heart failure in dogs with degenerative mitral valve disease: The PREDICT cohort study

ObjectiveTo identify risk factors for first-onset congestive heart failure (CHF) in dogs with degenerative mitral valve disease (DMVD).AnimalsEighty-two dogs with and without CHF secondary to DMVD were retrospectively assigned to a derivation cohort. Sixty-five dogs with asymptomatic DMVD were recruited into a prospective validation cohort.MethodsVariables associated with risk of CHF in dogs were identified in a derivation cohort and used to construct a predictive model, which was then prospectively tested through longitudinal examination of a validation cohort.ResultsLogistic regression analysis of the derivation cohort yielded a predictive model that included the left atrial to aortic root dimension ratio (LA:Ao) and plasma concentration of N-terminal pro-B-type natriuretic peptide (NT-proBNP). When this model was prospectively applied to the validation cohort, it correctly predicted first-onset of CHF in 69.2% of cases. Analysis of the validation cohort revealed that plasma NT-proBNP concentration and indexed left ventricular end-diastolic diameter (LVIDd:Ao) were independent risk factors for development of first-onset CHF in dogs with DMVD (NT-proBNP ≥1500 pmol/L, odds ratio (OR), 5.76, 95% confidence interval (CI), 1.37–24.28, P = 0.017; LVIDd:Ao ≥3, OR, 6.11, 95% CI, 1.09–34.05, P = 0.039).ConclusionsMeasures of left heart size and plasma NT-proBNP concentration independently estimate risk of first-onset of CHF in dogs with DMVD. These parameters can contribute to the management of dogs with DMVD.     

Brain natriuretic peptide concentration in dogs with heart disease and congestive heart failure

Plasma brain natriuretic peptide concentration ([BNP]) is high in humans with cardiac disease and is further increased with congestive heart failure (CHF). The hypotheses of this study were that dogs with moderate to severe mitral regurgitation due to myxomatous mitral valve disease (MVD) would have increased plasma [BNP] compared to normal dogs, that plasma [BNP] would be higher in dogs with CHP, and that plasma [BNP] would predict premature death from cardiovascular disease. The study population consisted of 34 dogs: 9 normal dogs and 25 dogs with MVD. Patients were divided into 4 groups: group 1-10 dogs with moderate to severe MVD and no radiographic evidence of CHF; group II--6 dogs with severe MVD and mild CHF; group III--7 dogs with severe MVD and moderate CHF; and group IV--2 dogs with severe MVD and severe CHF. Diagnostic tests included thoracic radiographs, an echocardiogram, a serum chemistry profile, and the measurement of plasma [BNP] by a canine-specific radioimmunoassay. There was a significant positive correlation between the plasma [BNP] and heart disease/failure groups (P = .0036). Plasma [BNP] increased with progressively increasing severity of MVD and CHE Group I dogs had higher plasma [BNP] than did control dogs (P < .0001), and plasma [BNP] was higher in dogs with CHF (groups II-IV versus group I; P = .012). Plasma [BNP] was also weakly positively correlated with left atrial size (r = 0.43, P = .04). For every 10-pg/mL increase in plasma [BNP], the mortality rate over 4 months' time increased approximately 44%.     

Predictive value of natriuretic peptides in dogs with mitral valve disease

Natriuretic peptides are useful in diagnosing heart failure in dogs. However, their usefulness in detecting early stages of myxomatous mitral valve disease (MMVD) has been debated. This study evaluated N-terminal (NT) fragment pro-atrial natriuretic peptide (NT-proANP) and NT-pro-brain natriuretic peptide (NT-proBNP) in 39 Cavalier King Charles Spaniels (CKCS) with pre-clinical mitral valve regurgitation (MR), sixteen dogs with clinical signs of heart failure (HF) and thirteen healthy control dogs. Twenty seven CKCS and ten control dogs were re-examined 4 years after the initial examination and the status of the dogs 5 years after the initial examination was determined by telephone calls to the owner. All dogs were evaluated by clinical examination and echocardiography. CKCS with severe MR had higher NT-proANP and NT-proBNP compared to controls and CKCS with less severe MR. Dogs with clinical signs of HF had markedly elevated NT-proANP and NT-proBNP. Plasma concentrations of the natriuretic peptides measured at re-examination could predict progression in regurgitant jet size.     

Serum Serotonin Concentrations in Dogs with Degenerative Mitral Valve Disease

Background: Increased serotonin (5HT) signaling has been implicated in valvular disease of humans and animals, including canine degenerative mitral valve disease (DMVD). High circulating 5HT concentration is a potential source of increased signaling, and serum 5HT concentrations have not been previously reported in dogs with DMVD.
Hypothesis: Dogs with DMVD and small breed dogs predisposed to DMVD have higher serum 5HT concentrations than large breed controls.
Animals: Fifty dogs affected with DMVD, 34 dogs predisposed to DMVD but without cardiac murmur or echocardiographic evidence of DMVD, and 36 healthy large breed control dogs.
Methods: Prospective analysis. Serum 5HT concentration was measured by an ELISA test.
Results: Median serum 5HT concentration was significantly higher in dogs with DMVD and in dogs predisposed to DMVD as compared with controls (DMVD, 765.5 ng/mL [interquartile range, 561.3–944.4]; predisposed, 774.9 ng/mL [528.3–1,026]; control, 509.8 ng/mL [320.8–708.8]; P = .0001). Subgroup analysis of predisposed dogs indicated significantly higher serum 5HT concentrations in Cavalier King Charles Spaniel (CKCS) dogs than in other breeds (CKCS, 855.0 ng/mL [635.8–1,088]; non-CKCS, 554.2 ng/mL [380.6–648.4]; P = .0023). Age, platelet count, and platelet morphology were not correlated with 5HT concentration in any group.
Conclusions and Clinical Importance: Dogs with DMVD had significantly higher serum 5HT concentrations when compared with large breed control dogs. Healthy CKCS dogs had significantly higher serum 5HT concentrations than other healthy dogs predisposed to DMVD. Additional investigation into a possible role of 5HT in the pathogenesis of DMVD is warranted.     

Cardiac troponin I concentrations following medetomidine‐butorphanol sedation in dogs

ObjectiveTo evaluate the effect of medetomidine–butorphanol sedation on serum cardiac troponin I (cTnI) concentration, a marker of myocardial ischemia and injury, in healthy dogs undergoing pre–surgical radiographs for orthopedic procedures.Study designProspective clinical study.AnimalsTwenty client–owned dogs with no history of cardiac disease.MethodsDogs were evaluated for pre–existing cardiac disease with electrocardiogram (ECG), noninvasive blood pressure and echocardiogram. Sedation was achieved using a combination of medetomidine (10 μg kg^?1) and butorphanol (0.2 mg kg^?1) intravenously. Blood pressure, heart rate and ECG were serially recorded throughout the duration of sedation. Serum cTnI concentration was measured at baseline and 6, 18, and 24–hours post–sedation.ResultsFollowing administration of medetomidine and butorphanol, all dogs were adequately sedated for radiographs and had a decreased heart rate and increased diastolic blood pressure. Arrhythmias associated with increased parasympathetic tone occurred, including a sinus arrhythmia further characterized as a sinus bigeminy in 17 of the dogs. Serum cTnI was undetectable at all time points in all but three dogs. Two of the three dogs had a detectable concentration of cTnI at all time points measured, including prior to sedation. Only one of the two dogs had a cTnI concentration above the normal reference interval. The dogs that exhibited detectable cTnI had no significant difference in signalment, heart rate, blood pressure, or lactate concentration as compared to those with undetectable cTnI.Conclusions and clinical relevanceSedation with medetomidine and butorphanol had predictable cardiovascular effects including bradycardia, an increase in arterial blood pressure, and arrhythmias in apparently healthy dogs requiring radiographs for orthopedic injuries, but did not induce significant increases in serum cTnI concentration following the drug doses used in this study.     

Evaluation of disease activity markers in dogs with idiopathic inflammatory bowel disease

OBJECTIVES: To evaluate the clinical utility of serum tumour necrosis factor-alpha, C-reactive protein and microalbuminuria as disease activity markers in canine idiopathic inflammatory bowel disease. METHODS: Dogs with chronic gastrointestinal disease for which no underlying cause could be identified were considered to have idiopathic inflammatory bowel disease and were included in the study. Serum tumour necrosis factor-alpha was assessed using a canine-specific ELISA, C-reactive protein by immunoturbidometric assay and quantitative microalbuminuria was analysed using a monoclonal antibody directed against canine albumin. The canine inflammatory bowel disease activity index and histopathologic grade were used to assess disease severity; biologic markers were then compared with the canine inflammatory bowel disease activity index and histopathologic grade. RESULTS: Sixteen dogs were included in the study. C-reactive protein level was mildly elevated in 15 dogs. Microalbuminuria was elevated in two of 15 dogs, and tumour necrosis factor-alpha was not detected in any dog tested. No correlation was found between the canine inflammatory bowel disease activity index and C-reactive protein or microalbuminuria or between histopathologic grade and C-reactive protein or microalbuminuria. There was no correlation between histopathologic grade and the canine inflammatory bowel disease activity index. CLINICAL SIGNIFICANCE: Although only a small number of dogs were evaluated, this study does not support the use of serum tumour necrosis factor-alpha measured by canine-specific ELISA or microalbuminuria in the evaluation of disease activity in dogs with idiopathic inflammatory bowel disease. Although mildly elevated in most dogs, C-reactive protein did not reflect disease severity as assessed by the canine inflammatory bowel disease activity index or histopathologic grade.