Plasma renin activity and aldosterone concentration in dogs with acquired portosystemic collaterals

Prognostic indicators in dogs with intra-hepatic portal hypertension

Objectives

The primary goals of this retrospective study were to describe a population of dogs with portal hypertension secondary to liver disease, and to assess whether prognosis could be inferred from historical, clinical, and clinicopathological data.

Animals and procedures

Dogs (N = 76) diagnosed with intrahepatic portal hypertension between 2011 and 2020 were included; dogs with known congenital hepatic anomalies were excluded. Effect on survival was assessed using univariable and multivariable Cox proportional hazards models for historical, clinical, and clinicopathological variables.

Results

Dogs survived for a median of 14 d (range: 0 to 2028 d), with 31.6% being euthanized within 2 d of diagnosis and 23.7% surviving longer than 2 mo. Presence of jaundice and duration of clinical signs, expressed in days, were significantly associated with outcome in the univariable analysis (HR = 1.846, 95% CI: 1.094 to 3.117, P = 0.02; HR = 0.995, 95% CI: 0.990 to 1.000, P = 0.033, respectively). However, only presence of jaundice was significantly associated with increased hazard of death in the multivariable analysis.

Conclusion

Results of this study show that portal hypertension is associated with a poor prognosis; however, some dogs can show prolonged survival.

Clinical relevance

Clinical data can guide decision-making for clinicians and owners.

Serum 25-hydroxyvitamin D and C-reactive protein and plasma von Willebrand concentrations in 23 dogs with chronic hepatopathies

BACKGROUND

Serum concentrations of 25-hydroxyvitamin D (25(OH)VD) and C-reactive protein (CRP) and von Willebrand's factor (vWF) concentration correlate with histopathologic disease grade and stage in chronic inflammatory and fibrotic hepatopathies (CH) in humans.

OBJECTIVES

To evaluate serum 25(OH)VD and serum CRP concentrations and plasma vWF concentration and determine if they correlate with histopathologic and biochemical variables in dog with CH.

ANIMALS

Twenty-three client-owned dogs with a histopathologic diagnosis of CH were prospectively enrolled.

METHODS

Blood samples were collected before liver biopsy. Correlations between biomarkers and clinical pathological and histopathologic variables were evaluated using Pearson's or Spearman's test.

RESULTS

Serum 25(OH)VD concentration (median, 213 nmol/L; range, 42-527 nmol/L) was negatively correlated with serum aspartate aminotransferase activity (AST; rho = -0.59, P < .01), polymorphonuclear neutrophil count (PMN; r = -0.46, P < .05), and positively correlated with serum albumin concentration (r = 0.69, P < .001). Serum CRP concentration (median, 7.4 μg/L; range, 1-44.9 μg/L) was positively correlated with overall histopathologic necroinflammatory activity (r = 0.78, P < .001) and fibrosis score (rho = 0.49, P < .05). Plasma vWF concentration (median, 73.3%; range, 15-141%) was positively correlated with fibrosis score (r = 0.53, P < .05) and prothrombin time (rho = 0.67, P < .01), and negatively correlated with serum albumin concentration (r = -0.73, P < .001).

CONCLUSION AND CLINICAL IMPORTANCE

In dogs with CH, serum 25(OH)VD concentration was negatively correlated with disease activity, whereas serum CRP concentration and plasma vWF concentration were positively correlated with histopathologic grade and stage. Our results provide preliminary evidence that these biomarkers may be useful to assess grade and stage of CH in dogs in the absence of liver biopsy.

Changes in renin-angiotensin-aldosterone system during cardiac remodeling after mitral valvuloplasty in dogs

BACKGROUND

Information regarding changes in renin-angiotensin-aldosterone system (RAAS) during cardiac remodeling after mitral valvuloplasty (MVP) in dogs remains lacking.

HYPOTHESIS/OBJECTIVES

To assess the longitudinal effects of MVP on circulating RAAS activity.

ANIMALS

Eight client-owned dogs receiving MVP for myxomatous mitral valve disease (MMVD).

METHODS

This is a cohort study. Plasma renin activity (PRA), angiotensin II (AT2), aldosterone (PAC), blood urea nitrogen (BUN), and creatinine concentrations, were measured in these dogs before (baseline) and at 3 consecutive monthly follow-ups (Post-1M, Post-2M, Post-3M). Echocardiography was concomitantly used to assess the process of cardiac recovery after MVP.

RESULTS

The echocardiography revealed a significant decrease in LVIDDN, LA/Ao, FS, E velocity, E/A, E' sep, S' lat, E' lat, and A' lat after MVP compared with baseline (P < .05). There was a significant reduction in the PRA (2.45, 3.05, 2.74 vs 8.8 ng/mL/h; P = .002), AT2 (466, 315, 235 vs 1200 pg/mL; P = .009), and PAC (39.88, 47, 54.62 vs 179.5 pg/mL; P = .01), respectively at Post-1M, Post-2M, Post-3M compared to the baseline. Additionally, BUN and creatinine concentrations decreased from Post-1M. The RAAS variables showed significant, weak to moderate, relationship with selected echocardiographic variables.

CONCLUSIONS AND CLINICAL IMPORTANCE

Mitral valvuloplasty contributes to decreased RAAS activity in MMVD dogs, which paralleled the process of cardiac reverse remodeling up to Post-3M. This information facilitates formulating strategies to optimize clinical outcomes for dogs after MVP.

Metabolic alkalosis following mitral valvuloplasty in a dog with preoperative acute kidney injury

CASE DESCRIPTION

An 11-year-old sexually intact male Shih Tzu diagnosed with acute kidney injury and left-sided congestive heart failure that had nonelective mitral valve surgery.

CLINICAL FINDINGS

Metabolic alkalosis developed postoperatively, and plasma bicarbonate concentration peaked 2 days after surgery (40.2 mmol/L; pH, 7.550).

TREATMENT AND OUTCOME

Acetazolamide administration increased the urinary excretion of bicarbonate and contributed to the improvement of the dog's acid-base status and oxygenation capacity. Metabolic alkalosis persisted for 4 days after surgery, and no treatment was required after resolution. Plasma urea nitrogen and creatinine concentrations normalized 2 days after surgery.

CLINICAL RELEVANCE

Severe metabolic alkalosis can occur as a complication following mitral valve surgery. Acetazolamide may be suitable for the treatment of severe metabolic alkalosis.

Plasma renin activity and aldosterone concentration in dogs with acquired portosystemic collaterals

Background

The renin‐angiotensin‐aldosterone system (RAAS) is activated in humans with portal hypertension (PH) associated with liver disease. However, involvement of RAAS in dogs with intrahepatic PH is not clear.

Objective

To measure plasma renin activity (PRA) and plasma aldosterone concentration (PAC) in dogs with PH (chronic hepatitis [CH] and primary hypoplasia of the portal vein [PHPV]), dogs with extrahepatic congenital portosystemic shunt (EH‐CPSS), and healthy dogs and to determine whether the RAAS is activated in dogs with PH.

Animals

Twenty‐seven dogs with acquired portosystemic collaterals (APSCs; 15 dogs with CH, 12 dogs with PHPV), 9 dogs with EH‐CPSS, and 10 healthy dogs.

Methods

Retrospective study. Plasma renin activity and PAC were measured by radioimmunoassay.

Results

Plasma renin activity was significantly higher in the CH group (median, 4.4 ng/mL/h) than in the EH‐CPSS (median, 1.0 ng/mL/h; P < .01) and the healthy (median, 1.1 ng/mL/h; P < .01) groups. No significant differences were found between the PHPV group (median, 2.2 ng/mL/h) and other groups. Plasma aldosterone concentration was significantly higher in the CH (median, 111.0 pg/mL) and PHPV (median, 89.5 pg/mL) groups than in the EH‐CPSS (median, 1.0 pg/mL; P < .001, P < .01, respectively) and healthy (median, 14.5 pg/mL; P < .001, P < .05, respectively) groups.

Conclusions and Clinical Importance

Activation of the RAAS contributes to the pathophysiology of intrahepatic PH in dogs, suggesting that spironolactone may not only be effective for the treatment of ascites but also for the suppression of intrahepatic PH.