Glomerular filtration rate in dogs with leishmaniasis and chronic kidney disease

BACKGROUND: Glomerular filtration rate (GFR) measurement is an indicator of kidney function. However, its usefulness in dogs at early stages of spontaneous chronic kidney disease (CKD) of glomerular origin, where routine laboratory techniques are not sufficiently sensitive, remains unproved. HYPOTHESIS: That GFR is reduced in proteinuric nonazotemic or mildly azotemic dogs with CKD secondary to leishmaniasis. ANIMALS: Twenty-six dogs with CKD secondary to leishmaniasis and 10 healthy dogs (control group). METHODS: CBC, serum biochemistry, and urinalysis (microalbuminuria and urine protein/creatinine ratio [UPC]) were performed in all dogs. GFR was calculated by measuring exogenous creatinine clearance. Based on degree of proteinuria and serum creatinine concentration (SCr), dogs were classified as group A (control; n = 10): UPC < 0.2, SCr < 1.4 mg/dL; group B (n = 8): UPC, 0.2-0.5, SCr < 1.4 mg/dL; group C (n = 10): UPC > 0.5, SCr < 1.4 mg/dL; group D (n = 5): SCr, 1.4-2 mg/dL; group E (n = 3): SCr > 2 mg/dL. Results: GFR (mL/kg/min) was 3.9 +/- 0.29, 4.4 +/- 0.74, 4.5 +/- 1.44, 2.8 +/- 0.97, and 1.5 +/- 0.43 for groups A, B, C, D, and E, respectively. Eleven dogs (1 from group B, 3 from group C, 4 from group D, and all 3 dogs from group E) had an abnormally low GFR. Four dogs from group B and 5 dogs from group C had a GFR above the upper reference range (>4.5 mL/min/kg). CONCLUSION AND CLINICAL RELEVANCE: Some proteinuric nonazotemic or mildly azotemic dogs with leishmaniasis have low GFR, but glomerular hyperfiltration occurs in other dogs.     

Survival of cats with naturally occurring chronic renal failure is related to severity of proteinuria

BACKGROUND: Tubulointerstitial kidney disease is a common cause of illness and death in pet cats and is typically not associated with overt proteinuria. HYPOTHESIS: Proteinuria would be independently related to survival in cats with renal failure, with or without hypertension. ANIMALS: The study included 136 client-owned cats; 28 apparently normal, 14 hypertensive but not azotemic, 66 azotemic but not hypertensive, and 28 both hypertensive and azotemic. METHODS: Cox's proportional hazards model was used to determine the influence of initial plasma creatinine concentration, proteinuria (urine protein-to-creatinine ratio or albumin-to-creatinine ratio), age, and systemic hypertension on the risk of death or euthanasia during the follow-up period. Multivariable linear regression was used to determine the relation between severity of proteinuria and predictive variables, including age, plasma creatinine concentration, systolic blood pressure, sex, and urine specific gravity. RESULTS: Plasma creatinine concentration and proteinuria were very highly related to survival. The hazard ratio (95% confidence intervals) for death or euthanasia was 2.9 (1.4-6.3) and 4.0 (2.0-8.0) for urine protein-to-creatinine ratio 0.2-0.4 and >0.4, respectively, compared with the baseline group with a urine protein-to-creatinine ratio of <0.2 and were 2.4 (1.2-4.8) and 4.9 (2.3-10.2) for an albumin-to-creatinine ratio of 30-82 mg/g and <82 mg/g, respectively, compared with a baseline group with albumin-to-creatinine ratio of <30 mg/g. Treated hypertensive cats did not have reduced survival, although systolic blood pressure, together with plasma creatinine concentration was positively related to the magnitude of proteinuria. CONCLUSIONS AND CLINICAL IMPORTANCE: Despite the relatively low concentrations of proteinuria typical of chronic renal disease in cats, this measurement is of prognostic significance.     

N-terminal pro B-type natriuretic peptide and left ventricular diameter independently predict mortality in dogs with mitral valve disease

Objectives : To determine whether natriuretic peptide concentrations would predict all cause mortality in dogs with degenerative mitral valve disease. Methods : One hundred dogs with naturally occurring degenerative mitral valve disease were prospectively recruited for this longitudinal study. Analysis of outcome was undertaken for 73 dogs for which the outcome was known. Dogs underwent physical examination, electrocardiography and echocardiography. Natriuretic peptide concentrations were measured by Enzyme-linked immunosorbent assay. The ability of natriuretic peptide concentrations, clinical, electrocardiographic and echocardiographic data, to predict all cause mortality was determined using univariable and multivariable Cox proportional hazards analyses. Results : Thirty dogs died during the period of follow-up. Two variables were independently predictive of all cause mortality; these were the normalised left ventricular end-diastolic diameter and the N-terminal pro B-type natriuretic peptide concentration. An increase of the left ventricular end-diastolic diameter by 0.1 increased the hazard of all cause mortality by 20% (95% confidence interval: 4 to 37%, P=0.01) and a 100 pmol/l increase in N-terminal pro B-type natriuretic peptide increased the hazard by 7% (95 confidence interval: 2 to 11%, P=0.003). Clinical Significance : N-terminal pro B-type natriuretic peptide concentration and left ventricular end-diastolic diameter are significantly and independently predictive of all cause mortality in dogs with degenerative mitral valve disease.     

Incremental predictive value of echocardiographic indices of right ventricular function in the assessment of long-term prognosis in dogs with myxomatous mitral valve disease

IntroductionFew studies have evaluated the utility of echocardiographic indices of right ventricular (RV) function in predicting prognosis in dogs with myxomatous mitral valve disease (MMVD).AnimalsSixty-seven client-owned dogs were diagnosed with MMVD.Materials and methodsclinical cohort study. Dogs diagnosed with American college of veterinary internal medicine (ACVIM) stage B2, C or D between April 2014 and March 2017 were enrolled. Long-term outcomes were assessed by telephone or from the medical record. The primary end-point was defined as cardiac-related death. Echocardiographic indices of RV function, including the RV Tei index, free wall and septal RV longitudinal strain, were obtained. Univariable and multivariable Cox proportional hazard analyses were used to identify variables predictive of cardiac-related death.ResultsTwenty-four dogs died during the follow-up period. The median follow-up time was 482 days, and the median survival time for dogs with cardiac-related death was 230 days. For cardiac-related death, peak early diastolic mitral inflow velocity, ACVIM stage C or D, tricuspid regurgitation velocity, RV Tei index and RV end-diastolic area were predictors in univariable Cox proportional hazard analysis. In multivariable Cox proportional analysis adjusted for the left atrial to aorta ratio, peak early diastolic mitral inflow velocity and ACVIM stage, an increase in the Tei index by 0.1 increased the hazard ratio of cardiac-related death by 33% (95% confidence interval, 16–70%; P = 0.002).ConclusionsIn dogs with MMVD, RV dysfunction assessed by the Tei index is an independent predictor of cardiac-related death.     

Ionized hypercalcemia in cats with azotemic chronic kidney disease (2012‐2018)

BackgroundHypercalcemia is associated with chronic kidney disease (CKD) in cats, but studies assessing the physiologically relevant ionized calcium fraction are lacking.ObjectivesTo describe the prevalence and incidence rate of ionized hypercalcemia, and to explore predictor variables to identify cats at risk of ionized hypercalcemia in a cohort of cats diagnosed with azotemic CKD.AnimalsOne hundred sixty‐four client‐owned cats with azotemic CKD.MethodsVariables independently associated with ionized hypercalcemia at diagnosis of azotemic CKD were explored by binary logistic regression. Cats that were normocalcemic at diagnosis of azotemic CKD were followed over a 12‐month period or until ionized hypercalcemia occurred and baseline predictor variables for ionized hypercalcemia explored using Cox proportional hazards and receiver operating characteristic curve analysis.ResultsIonized hypercalcemia (median, 1.41 mmol/L; range, 1.38‐1.68) was observed in 33/164 (20%) cats at diagnosis of azotemic CKD and was associated with male sex, higher plasma total calcium and potassium concentrations, and lower plasma parathyroid hormone concentrations. Twenty‐five of 96 initially normocalcemic (26%) cats followed for minimum 90 days developed ionized hypercalcemia (median, 1.46 mmol/L; range, 1.38‐1.80) at a median of 140 days after diagnosis of azotemic CKD (incidence rate, 0.48 per feline patient‐year). Only body condition score was independently associated with incident ionized hypercalcemia.Conclusions and Clinical ImportanceThe occurrence of ionized hypercalcemia is high in cats with CKD. Continued monitoring of blood ionized calcium concentrations is advised.     

Calcium and Phosphorus Homeostasis in Dogs with Spontaneous Chronic Kidney Disease at Different Stages of Severity

Background: Studies in dogs with experimental chronic kidney disease (CKD) have demonstrated that abnormalities of calcium-phosphorus (Ca-P) homeostasis occur frequently and have a negative effect on kidney function and survival. However, the prevalence of these alterations in dogs with naturally occurring CKD at different stages of severity has not yet been investigated.
Hypothesis: Abnormalities of Ca-P metabolism occur early in the course of CKD with an increased prevalence in more severe stages.
Animals: Fifty-four dogs with CKD and 22 healthy dogs.
Methods: Blood and urine samples were obtained for a CBC, biochemistry, determination of parathyroid hormone (PTH), calcitriol, and ionized calcium concentrations and urinalysis. Based on urine protein/creatinine ratio and serum creatinine concentration, dogs were grouped according to the IRIS classification for CKD.
Results: Hyperparathyroidism (HPTH) (PTH ≥ 48 pg/mL) was diagnosed in 41 (75.9%) dogs with CKD. Its prevalence increased from 36.4% (stage 1) to 100% (stage 4). Hyperphosphatemia ( P > 5.5 mg/dL) was present in 37 (68.5%) dogs; increasing in prevalence from 18% (stage 1) to 100% (stage 4). Receiver-operating characteristic curve analysis showed that serum phosphorus concentration in the 4.5–5.5 mg/dL range correctly identified the presence of HPTH in most dogs. Calcitriol concentration progressively decreased in dogs with CKD and differences became statistically significant by stage 3.
Conclusion and Clinical Relevance: HPTH and hyperphosphatemia occur frequently in dogs with naturally occurring CKD, even at early stages of CKD in some dogs. These findings highlight the importance of monitoring these parameters early in the course of CKD.     

N-acetyl-beta-D-glucosaminidase index as an early biomarker for chronic kidney disease in cats with hyperthyroidism

Background: Hyperthyroid cats are at risk of developing azotemic chronic kidney disease (CKD) and diagnostic tools currently used to screen for CKD in hyperthyroid cats are either unreliable or impractical.
Hypothesis: Urine N -acetyl-β- d -glucosaminidase index (NAG_i) is a good biomarker for azotemic CKD in hyperthyroid cats.
Animals: Twenty-four newly diagnosed nonazotemic hyperthyroid cats and 10 healthy cats.
Methods: All cats were evaluated for hyperthyroidism at baseline. Hyperthyroid cats were treated with methimazole and reevaluated once euthyroid. At the end of the study, cats were divided into 3 groups: healthy cats, nonazotemic, and azotemic euthyroid cats. Baseline group characteristics were compared to predict azotemic CKD. The influence of treatment on NAG_i was evaluated.
Results: Baseline NAG_i was significantly different among groups ( P = .004). Azotemic cats had a higher median value (13.12 U/g) when compared with healthy cats (1.38 U/g). With NAG_i >2.76 U/g, negative and positive predictive values for development of azotemia were 77.7 and 50%, whereas the combination of a urine specific gravity (USG) ≤1.035 and T₄ >7.80 μg/dL enhanced predictive values to 88.9 and 83.3%, respectively. NAG_i values decreased significantly over time in treated nonazotemic cats.
Conclusions and Clinical Relevance: Baseline NAG_i did not differentiate azotemic from nonazotemic euthyroid cats. NAG_i could be used to assess renal function during medical therapy allowing the clinician to adjust methimazole dosage accordingly. The combination of USG and T₄ could optimize identification of appropriate candidates for permanent treatment of hyperthyroidism.     

Correlation of electrophoretic urine protein banding patterns with severity of renal damage in dogs with proteinuric chronic kidney disease

Background

Urine protein loss is common in dogs with chronic kidney disease (CKD). Currently available noninvasive means of evaluating CKD in dogs cannot accurately predict the severity of glomerular and tubulointerstitial damage. Electrophoretic analysis of urine proteins can indicate the compromised renal compartment (glomerular vs tubular), but extensive evaluation of protein banding pattern associations with histologic damage severity has not been performed in dogs.

Objectives

We aimed to evaluate electrophoretic banding patterns as indicators of the presence and severity of glomerular and tubulointerstitial damage in dogs with naturally occurring, predominantly proteinuric CKD.

Methods

We performed a retrospective study using urine and renal tissue from 207 dogs with CKD. Urine protein banding patterns were correlated with histologic severity of renal damage. Sensitivity and specificity of banding patterns for the detection of glomerular and tubulointerstitial damage were determined.

Results

Banding patterns were 97% sensitive and 100% specific for the detection of glomerular damage and 90% sensitive and 100% specific for the detection of tubulointerstitial damage. Correlations between composite banding patterns and the severity of renal damage were strong, while glomerular banding patterns correlated moderately with glomerular damage severity, and tubular gel scores correlated weakly to moderately with the severity of tubulointerstitial damage.

Conclusions and clinical importance

Urine protein banding patterns are useful for the detection of glomerular and tubulointerstitial damage in dogs with proteinuric CKD.     

Risk factors for excessive tibial plateau angle in large-breed dogs with cranial cruciate ligament disease

OBJECTIVE: To identify risk factors for development of excessive tibial plateau angle (TPA) in large-breed dogs with cranial cruciate ligament disease (CCLD). DESIGN: Case-control study. ANIMALS: 58 dogs with excessive TPAs (ie, TPA >or= 35 degrees ; case dogs) and 58 dogs with normal TPAs (ie, TPA or= 35 degrees in both limbs were 13.6 times (95% confidence interval, 2.72 to 68.1) as likely to have been neutered before 6 months of age as were control dogs with TPA 相似文献   

Azotemia and glomerular filtration rate in dogs with chronic valvular disease

BACKGROUND: Little information is available about the prevalence of renal dysfunction in dogs with chronic valvular heart disease (CVD). HYPOTHESIS: Azotemia and a decrease in glomerular filtration rate (GFR) are more severe with increased severity of CVD. ANIMALS: 124 (study No. 1) and 24 (study No. 2) client-owned dogs with CVD. METHODS: A retrospective study (study No. 1) was performed to assess the prevalence of azotemia in the New York Heart Association (NYHA) classes of heart failure in dogs with CVD. A prospective study (study No. 2) was then designed to determine GFR in dogs with different degrees of CVD severity. Complete physical examination, electrocardiography, blood pressure measurement, thoracic radiographs, echocardiography, and plasma and urine analyses were also performed. RESULTS: In study No. 1, 50% of the dogs were azotemic and the percentage of azotemic dogs increased with functional class (up to 70% in NYHA class IV patients). In study No. 2, 8/24 dogs were azotemic. Plasma urea and creatinine were higher in NYHA class III-IV dogs compared with class I-II dogs. The GFR was lower (P < .001) in NYHA class III-IV dogs (1.7 +/- 0.7 mL/min/kg) than in class I to II dogs (3.1 +/- 0.8 mL/min/kg). Only 1 dog in class I-II had a GFR below 2 mL/min/kg and only 2/9 class III-IV dogs had a GFR above 2 mL/min/kg. CONCLUSION AND CLINICAL RELEVANCE: Azotemia and renal impairment increase with the severity of congestive heart failure and are frequent findings in dogs with CVD. It remains to be shown if deterioration of renal function is a direct result of progression of the heart disease.     

Plasma pro-opiomelanocortin, pro-adrenocorticotropin hormone, and pituitary adenoma size in dogs with Cushing's disease

It is difficult to predict the size of pituitary corticotroph tumors in dogs with Cushing's disease (pituitary-dependent hyperadrenocorticism [PDH]) without pituitary imaging techniques. The purpose of this study was to examine the relationship between plasma adrenocorticotropin hormone (ACTH) precursor concentration and pituitary size in dogs with Cushing's disease. Plasma concentrations of ACTH precursors (pro-opiomelanocortin [POMC]/pro-ACTH) and pituitary tumor height/brain area were measured in 36 dogs with pituitary corticotroph adenomas of various sizes. There was a correlation between tumor size (measured as the pituitary tumor height/brain area ratio [P/B]) and POMC/pro-ACTH concentration (r = .70; P < .0001). Dogs with P/B > or = 0.40 x 10(-2) mm(-1) had higher concentrations of ACTH precursors than dogs with P/B < 0.40 x 10(-2) mm(-1) (median concentration 85 pmol/L, range 15-1,350 pmol/L, n = 14 versus 15 pmol/L, range 15-108 pmol/L, n = 22; P < .0001). With a threshold of 35 pmol/L of POMC/pro-ACTH concentration, the estimated sensitivity and specificity of the kit were 93% (95% confidence interval [CI], 79-100%) and 86% (95% CI, 73-100%), respectively. We interpret these data as indicating that measurement of POMC and pro-ACTH might be of value in the characterization of tumor size in dogs with Cushing's disease. Low POMC/pro-ACTH concentrations make it unlikely that a large pituitary tumor exists in dogs with PDH.     

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.     

Cholangitis and Cholangiohepatitis in Dogs: A Descriptive Study of 54 Cases Based on Histopathologic Diagnosis (2004–2014)

Background

Cholangitis in dogs appears to be more common than previously thought, but understanding of the disease remains incomplete.

Objective

To describe a population of dogs with cholangitis or cholangiohepatitis.

Animals

Fifty‐four client‐owned dogs with cholangitis or cholangiohepatitis.

Methods

Medical records of dogs with cholangitis or cholangiohepatitis confirmed by histopathology between January 2004 and December 2014 were identified using a computer‐based search and retrospectively reviewed.

Results

Clinical signs included vomiting (72.2%), lethargy (70.4%), and inappetence (64.8%). Most dogs (49/50) had increased liver enzyme activities, hyperbilirubinemia (32/50), and hypercholesterolemia (24/43). Ultrasonographic abnormalities of the hepatobiliary system were seen in 84% of cases. On histopathology, 53 of 54 affected dogs had neutrophilic cholangitis (NC) or cholangiohepatitis, whereas 1 dog had lymphocytic cholangitis. Most cases (42/54) were chronic. Evidence of concurrent biliary disease (46.2%) and biliary tract obstruction (42.6%) was common. Seventeen of 36 biliary and 11 of 25 liver cultures were positive for bacterial growth; Escherichia coli and Enterococcus spp. were most common. Median patient survival was 671 days (95% confidence interval [CI]: 114–1,426). On Cox regression, dogs that did not have a cholecystectomy performed had a 2.1 greater hazard for death (P = 0.037; 95% CI: 1.0–4.3) compared to cholecystectomized dogs. Dogs >13 years old had a 5.0 greater hazard for death (P = 0.001; 95% CI: 1.9–13.2) compared to younger dogs.

Conclusions and Clinical Significance

Chronic NC or cholangiohepatitis was most common. Cholecystitis and biliary tract obstruction often occurred in conjunction with cholangitis. Cholecystectomized dogs had decreased risk of death; thus, cholecystectomy may improve patient outcome.     

Evaluation of factors associated with survival in dogs with untreated nasal carcinomas: 139 cases (1993-2003)

OBJECTIVE: To evaluate factors associated with survival in dogs with nasal carcinomas that did not receive treatment or received only palliative treatment. DESIGN: Retrospective case series. ANIMALS: 139 dogs with histologically confirmed nasal carcinomas. PROCEDURES: Medical records, computed tomography images, and biopsy specimens of nasal carcinomas were reviewed. Only dogs that were not treated with radiation, surgery, chemotherapy, or immunotherapy and that survived > or = 7 days from the date of diagnosis were included. The Kaplan-Meier method was used to estimate survival time. Factors potentially associated with survival were compared by use of log-rank and Wilcoxon rank sum tests. Multivariable survival analysis was performed by use of the Cox proportional hazards regression model. RESULTS: Overall median survival time was 95 days (95% confidence interval [CI], 73 to 113 days; range, 7 to 1,114 days). In dogs with epistaxis, the hazard of dying was 2.3 times that of dogs that did not have epistaxis. Median survival time of 107 dogs with epistaxis was 88 days (95% CI, 65 to 106 days) and that of 32 dogs without epistaxis was 224 days (95% CI, 54 to 467 days). CONCLUSIONS AND CLINICAL RELEVANCE: The prognosis of dogs with untreated nasal carcinomas is poor. Treatment strategies to improve outcome should be pursued.     

A longitudinal study on the acceptance and effects of a therapeutic renal food in pet dogs with IRIS‐Stage 1 chronic kidney disease

Currently, nutritional management is recommended when serum creatinine (Cr) exceeds 1.4 mg/dl in dogs with IRIS‐Stage 2 chronic kidney disease (CKD) to slow progressive loss of kidney function, reduce clinical and biochemical consequences of CKD, and maintain adequate nutrition. It is unknown if dietary interventions benefit non‐azotemic dogs at earlier stages. A prospective 12‐month feeding trial was performed in client‐owned dogs with IRIS‐Stage 1 CKD (n = 36; 20 had persistently dilute urine with urine specific gravity (USG) <1.020 without identifiable non‐renal cause; six had persistent proteinuria of renal origin with urine protein creatinine (UPC) ratio >0.5; 10 had both). Ease of transition to therapeutic renal food and effects on renal biomarkers and quality of life attributes were assessed. Dogs were transitioned over 1 week from grocery‐branded foods to renal food. At 0, 3, 6, 9, and 12‐months a questionnaire to assess owner's perception of their pet's acceptance of renal food and quality of life was completed. Renal biomarkers, including serum Cr, blood urea nitrogen (BUN), and symmetric dimethylarginine (SDMA), and USG and UPC ratio were measured. Of 36 dogs initially enrolled, 35 (97%) dogs were transitioned to therapeutic renal food. Dogs moderately or extremely liked the food 88% of the time, ate most or all of the food 84% of the time, and were moderately or extremely enthusiastic while eating 76% of the time. All renal biomarkers (Cr, BUN, and SDMA) were decreased (p ≤ .05) from baseline at 3‐months, and remained decreased from baseline at 12‐months in dogs completing the study (n = 20). Proteinuria was reduced in 12 of 16 dogs (p = .045) with proteinuria. Owners reported improvement in overall health and quality of life attributes, and hair and coat quality (all p < .01). In summary, dogs with IRIS‐Stage 1 CKD readily transition to renal food. Decreasing serum biomarker concentrations and reduction in proteinuria suggest stabilized kidney function.     

Plasma endothelin-1 immunoreactivity in normal dogs and dogs with acquired heart disease

We sought to measure plasma endothelin-1 (ET-1) concentrations in normal dogs and to compare them with those measured in dogs with acquired heart disease with or without pulmonary edema. A sandwich enzyme-linked immunosorbent assay kit was validated and used to measure ET-1 immunoreactivity in plasma samples obtained from 32 normal dogs and 46 dogs with either dilated cardiomyopathy (DCM, n = 27) or degenerative valvular disease (CDVD, n = 19) with (n = 30) or without (n = 16) overt congestive heart failure (CHF). Plasma ET-1 concentrations (geometric mean, 95% confidence interval of geometric mean) were 1.17 (1.04-1.32) fmol/mL in the 32 normal control dogs, 1.25 (0.981-1.60) fmol/mL in 16 dogs with DCM (n = 9) or CDVD (n = 7) without CHF, and 2.51 (2.10-3.01) fmol/mL in 30 dogs with DCM (n = 18) and CDVD (n = 12) with CHE Plasma immunoreactivity of ET-1 was significantly higher in dogs with CHF in comparison with normal dogs (P < .001) and dogs with heart disease without CHF (P < .001). No significant difference was found between normal dogs and dogs with heart disease but without CHF (P > .05). Significant correlations were between plasma ET-I concentrations and left atrial:aortic ratio (P < .0001, r2 = .39), left ventricular internal dimension at end-diastole indexed to aortic diameter (P < .0001, r2 = .30) or body surface area (BSA) (P = .0071, r2 = .10), and left ventricular internal dimension at end-systole indexed to aortic diameter (P = .0003, r- = .17) or BSA (P = .0008, r2 = .15).     

Association between canine malignant lymphoma, living in industrial areas, and use of chemicals by dog owners

A case-control study was carried out to determine whether residential exposure to environmental pollutants increased risk for canine lymphoma in pet dogs. One hundred one cases with cytologically or histologically confirmed lymphoma diagnosed at a veterinary teaching hospital between the middle of 1996 and the middle of 1998 were examined. Controls were obtained by choosing twice the number of dogs without neoplastic disease, with overlapping distributions of province of residence, age, sex, and breed. Information regarding animal management, residence type, professional or hobby use of chemicals by owners, and treatment with herbicides or other pesticides in the area frequently visited by the dogs was obtained with a multiple-choice questionnaire by telephone interview. Two variables were positively and independently associated with the disease, namely residency in industrial areas (odds ratio [OR]; = 8.5; 95% confidence interval [CI], 2.3-30.9) and use of chemicals by owners, specifically paints or solvents (OR = 4.6; 95% CI, 1.7-12.6). A significantly lower value of the mean age of disease onset was found in the group of dogs at risk in comparison with the group of all other dogs (6.1 +/- 0.4 years, n = 36 versus 7.5 +/- 0.4 years, n = 65, respectively; P = .008). Variables describing animal care and pesticide use were either not associated with the disease or were uninformative. We suggest that canine lymphoma may be considered a sentinel of potentially hazardous situations for humans, because of the relatively short latency between exposure and disease onset.     

Plasma asymmetric dimethylarginine, symmetric dimethylarginine, l-arginine, and nitrite/nitrate concentrations in cats with chronic kidney disease and hypertension

BACKGROUND: Chronic kidney disease (CKD) and hypertension have been associated with decreased bioavailability of nitric oxide (NO) and endothelial dysfunction. Increased concentrations of the endothelial nitric oxide synthase (eNOS) inhibitor asymmetric dimethylarginine (ADMA) are implicated. HYPOTHESIS: Plasma ADMA concentration is increased in cats with CKD and systemic hypertension corresponding to a decrease in total plasma nitrate/nitrite (NOx) availability. Decrease in systolic blood pressure (SBP) and proteinuria during treatment of hypertension with amlodipine besylate may be associated with increased NOx availability. ANIMALS: Sixty-nine client-owned normotensive and hypertensive cats with variable azotemia. METHODS: Plasma ADMA, symmetric dimethylarginine (SDMA), and l-arginine were measured simultaneously by hydrophilic-interaction liquid chromatography-electrospray tandem mass spectrometry in cats from 6 groups: normotensive nonazotemic (n = 10), normotensive mildly azotemic (n = 10), hypertensive mildly azotemic with hypertensive retinopathy (n = 20), hypertensive mildly azotemic without hypertensive retinopathy (n = 10), normotensive moderately azotemic cats (n = 10), and hypertensive nonazotemic cats (n = 9). Plasma NOx concentrations were measured. RESULTS: A moderate correlation between plasma creatinine and ADMA (n = 69, r= .608, P < .001), SDMA (n = 69, r= .741, P < .001), and NOx concentrations (n = 69, r= .589, P < .001) was observed. There was no association among plasma ADMA, SDMA, and NOx concentrations and SBP. CONCLUSIONS AND CLINICAL IMPORTANCE: Plasma ADMA and SDMA concentrations are increased in cats with CKD and correlate with plasma creatinine concentration. This may imply the presence of endothelial dysfunction in cats with CKD. Plasma ADMA concentrations were not associated with systemic hypertension. Treatment of systemic hypertension with amlodipine besylate did not affect plasma ADMA or NOx concentrations.     

Efficacy and safet of pimobendan in canine heart failure caused by myxomatous mitral valve disease

OBJECTIVES: To evaluate the clinical efficacy and safety of pimobendan by comparing it with ramipril over a six-month period in dogs with mild to moderate heart failure (HF) caused by myxomatous mitral valve disease (MMVD). METHODS: This was a prospective randomised, single-blind, parallel-group trial. Client-owned dogs (n = 43) with mild to moderate HF caused by MMVD were randomly assigned to one of two groups, which received either pimobendan (P dogs) or ramipril (R dogs) for six months. The outcome measures studied were: adverse HF outcome, defined as failure to complete the trial as a direct consequence of HF; maximum furosemide dose (mg/kg/day) administered during the study period; and any requirement for additional visits to the clinic as a direct consequence of HF. RESULTS: Treatment with pimobendan was well tolerated compared with treatment with ramipril. P dogs were 25 per cent as likely as R dogs to have an adverse HF outcome (odds ratio 4.09, 95 per cent confidence interval 1.03 to 16.3, P = 0.046). CLINICAL SIGNIFICANCE: R dogs had a higher overall score and thus may have had more advanced disease than P dogs at baseline (P = 0.04). These results should be interpreted cautiously but such a high odds ratio warrants further investigation.