Renin-Angiotensin-Aldosterone System Profiling in Horses Before and After Exercise.

Background: The impact of exercise on the classical and alternative renin-angiotensin-aldosterone system (RAAS) pathways has not been studied in horses.

Hypothesis: We hypothesized that exercise would activate both RAAS pathways and that endurance exercise would cause more activation of the classical pathway compared to short-duration, high-intensity exercise in horses.

Animals: Twenty-five horses (21 client-owned and 4 research) were included in 4 exercise groups (10 Arabians, 50-mile ride [A-E]; 4 thoroughbreds, 1-mile treadmill exercise [TB-TM]; 5 thoroughbreds, 1-1/16th-mile race [TB-R]; and 6 quarter horses 330-500-yard race [QH-R]).

Antidiuretic hormone concentrations in dogs with heart disease and relationship to serum chloride.

Introduction/objectives: Non-osmotic antidiuretic hormone (ADH) release promotes electrolyte-free water retention in dogs with congestive heart failure (CHF), contributing to low electrolyte concentrations. We hypothesized that dogs with CHF would have higher ADH concentrations than healthy dogs and dogs with preclinical heart disease, and that ADH concentrations would positively correlate to the amount of chloride [Cl] correction but not serum osmolality.

Animals, Materials And Methods: The study population comprised 20 healthy, 20 preclinical, and 20 CHF dogs.

Frequency and progression of azotemia during acute and chronic treatment of congestive heart failure in cats.

Background: Azotemia is common in cats with congestive heart failure (CHF) and might be exacerbated by diuretic therapy.

Hypothesis/objectives: Determine frequency, risk factors, and survival impact of progressive azotemia in cats treated for CHF.

Animals: One hundred and sixteen client-owned cats with kidney function testing performed at least twice during acute or chronic CHF treatment.

Correlation of serum chloride concentrations with components of the renin-angiotensin-aldosterone system in a dog with congestive heart failure.

A 7-year-old male castrated Cavalier King Charles Spaniel was hospitalized for 12 days for treatment of severe congestive heart failure secondary to myxomatous mitral valve disease. During that time, 6 serum samples from different days were analyzed for serum biochemical and renin-angiotensin-aldosterone system components. Serum chloride concentrations (ranging from 71.

Evaluation of Renin-Angiotensin-Aldosterone System Components and Enzymes in Systemically Hypertensive Cats Receiving Amlodipine.

Background: Chronic renin-angiotensin-aldosterone system (RAAS) activation is harmful. Amlodipine activates RAAS in humans and dogs, but contradictory data exist for systemically hypertensive (SHT) cats.

Hypothesis: Cats with SHT and chronic kidney disease treated with amlodipine (SHT/CKD-A) are RAAS activated.

Use of serum osmolality to identify heart disease stage in dogs and relationship to mathematical chloride correction.

Background: Heart failure-associated hypochloremia can be depletional from diuretics or dilutional from water retention. Serum osmolality reflects water balance but has not been evaluated in dogs with heart disease.

Hypothesis: To determine if serum osmolality is related to heart disease stage and amount of mathematical correction of serum chloride (Cl ) concentrations in healthy dogs and dogs with myxomatous mitral valve degeneration (MMVD).

Myocardial Enhancement Following Agitated Saline Contrast Study in a Boxer Dog.

• Myocardial enhancement after agitated saline contrast study in a dog is described. • Suspect air microemboli can inadvertently be introduced into coronary vasculature. • Air microemboli are a theoretic risk of saline contrast echocardiography.

Beyond Angiotensin-Converting Enzyme Inhibitors: Modulation of the Renin-Angiotensin-Aldosterone System to Delay or Manage Congestive Heart Failure.

The renin-angiotensin-aldosterone system (RAAS) consists of bioactive angiotensin peptides, enzymatic pathways, receptors, and the steroid hormone aldosterone. The RAAS regulates blood pressure, sodium, and electrolyte homeostasis and mediates pathologic disease processes. Within this system is an alternative arm that counterbalances the vasoconstrictive, sodium and water retentive, and pro-fibrotic and inflammatory effects of the classical arm.

The effect of taurine supplementation on the renin-angiotensin-aldosterone system of dogs with congestive heart failure.

The role of taurine in the treatment of congestive heart failure (CHF) in dogs without systemic deficiency is unexplored. Taurine might have beneficial cardiac effects aside from deficit replacement. We hypothesized that oral taurine supplementation administered to dogs with naturally-occurring CHF would suppress the renin-angiotensin aldosterone system (RAAS).

Angiotensin-converting enzyme 2 in dogs with Dirofilaria immitis.

Background: Infection by the canine heartworm, Dirofilaria immitis, causes significant cardiopulmonary disease, with progression impacted by increasing parasite numbers and duration of infection. The renin-angiotensin-aldosterone system (RAAS) is an important mediator of cardiac and pulmonary disease. Angiotensin-converting enzyme 2 (ACE2) mitigates the maladaptive effects of angiotensin II by converting it to angiotensin (1-7).

Metabolomic profiling in dogs with dilated cardiomyopathy eating non-traditional or traditional diets and in healthy controls.

Dilated cardiomyopathy (DCM), caused by genetic and environmental factors, usually progresses to heart failure, a major cause of death in elderly people. A diet-associated form of DCM was recently identified in pet dogs eating non-traditional (NT) diets. To identify potential dietary causes, we analyzed metabolomic signatures and gene set/pathway enrichment in (1) all dogs based on disease, diet, and their interactions and (2) dogs with DCM based on diet.

Influence of sex on renin-angiotensin-aldosterone system metabolites and enzymes in Doberman Pinschers.

Background: Estrogen modulates the renin-angiotensin-aldosterone system (RAAS) in women, but sex differences have not been fully explored in dogs.

Objective: We hypothesized that the RAAS profile of intact female (IF) Doberman Pinschers (DP) would differ from spayed female (SF) and intact male (IM) DP.

Animals: Eighteen healthy DP (6 IF, 6 SF, 6 IM).

Toward quantification of loop diuretic responsiveness for congestive heart failure.

Diuretics, such as furosemide, are routinely administered to dogs with congestive heart failure (CHF). Traditionally, dose and determination of efficacy primarily are based on clinical signs rather than quantitative measures of drug action. Treatment of human CHF patients increasingly is guided by quantification of urine sodium concentration (uNa) and urine volume after diuretic administration.

Retrospective evaluation of risk factors for development of kidney injury after parenteral furosemide treatment of left-sided congestive heart failure in dogs.

Background: Kidney injury (KI) has been documented in dogs treated with furosemide for left-sided congestive heart failure (CHF).

Hypothesis/objectives: Determine risk factors for development of KI in furosemide-treated dogs and determine the effect of KI on survival.

Animals: Seventy-nine client-owned dogs receiving parenteral furosemide for CHF.

Untargeted global metabolomic profiling of healthy dogs grouped on the basis of grain inclusivity of their diet and of dogs with subclinical cardiac abnormalities that underwent a diet change.

Objective: To compare metabolomic profiles of dogs eating grain-free (GF) versus grain-inclusive (GI) diets (1) for healthy dogs at baseline and (2) for dogs with subclinical cardiac abnormalities at 12 months after a diet change.

Sample: Serum samples from 23 dogs eating GF diets and 79 dogs eating GI diets, of which 17 (8 eating a GF diet and 9 eating a GI diet) were reevaluated 12 months after a diet change.

Procedures: Metabolomic profiles were developed by means of ultrahigh-performance liquid chromatography-tandem mass spectroscopy of serum samples.

Effect of diet change in healthy dogs with subclinical cardiac biomarker or echocardiographic abnormalities.

Background: A recent study showed higher high-sensitivity cardiac troponin I (hs-cTnI) concentrations in healthy dogs eating grain-free (GF) compared to those eating grain-inclusive (GI) diets.

Hypothesis/objectives: Healthy dogs with subclinical cardiac abnormalities eating GF diets at baseline will show improvements in cardiac biomarkers and echocardiographic variables after diet change, whereas healthy dogs eating GI diets at baseline will not improve.

Animals: Twenty healthy dogs with subclinical cardiac abnormalities (12 Golden Retrievers, 5 Doberman Pinschers, 3 Miniature Schnauzers).

Myxomatous mitral valve disease in Miniature Schnauzers and Yorkshire Terriers: 134 cases (2007-2016).

Objective: To characterize features of myxomatous mitral valve disease (MMVD) in Miniature Schnauzers and Yorkshire Terriers.

Animals: 69 Miniature Schnauzers and 65 Yorkshire Terriers, each with MMVD.

Procedures: Medical record data for each dog were collected; the study period was January 2007 through December 2016.

Prevalence of an angiotensin-converting enzyme gene variant in dogs.

Background: Genetic heterogeneity of the canine angiotensin converting enzyme (ACE) gene is functionally important because the degree of aldosterone breakthrough with ACE-inhibitor therapy is greater in variant positive dogs compared to variant negative dogs, but the prevalence of the variant is not known. The purpose of this study was to determine ACE gene variant-positive prevalence in a population of 497 dogs of different breeds.

Results: Overall variant-positive prevalence was 31%, with 20% of dogs heterozygous and 11% of dogs homozygous.