A review of renal tubular acidosis.

OBJECTIVE: To review the current scientific literature on renal tubular acidosis (RTA) in people and small animals, focusing on diseases in veterinary medicine that result in secondary RTA. DATA SOURCES: Scientific reviews and original research publications on people and small animals focusing on RTA. SUMMARY: RTA is characterized by defective renal acid-base regulation that results in normal anion gap hyperchloremic metabolic acidosis. Renal acid-base regulation includes the reabsorption and regeneration of bicarbonate in the renal proximal tubule and collecting ducts and the process of ammoniagenesis. RTA occurs as a primary genetic disorder or secondary to disease conditions. Based on pathophysiology, RTA is classified as distal or type 1 RTA, proximal or type 2 RTA, type 3 RTA or carbonic anhydrase II mutation, and type 4 or hyperkalemic RTA. Fanconi syndrome comprises proximal RTA with additional defects in proximal tubular function. Extensive research elucidating the genetic basis of RTA in people exists. RTA is a genetic disorder in the Basenji breed of dogs, where the mutation is known. Secondary RTA in human and veterinary medicine is the sequela of diseases that include immune-mediated, toxic, and infectious causes. Diagnosis and characterization of RTA include the measurement of urine pH and the evaluation of renal handling of substances that should affect acid or bicarbonate excretion. CONCLUSIONS: Commonality exists between human and veterinary medicine among the types of RTA. Many genetic defects causing primary RTA are identified in people, but those in companion animals other than in the Basenji are unknown. Critically ill veterinary patients are often admitted to the ICU for diseases associated with secondary RTA, or they may develop RTA while hospitalized. Recognition and treatment of RTA may reverse tubular dysfunction and promote recovery by correcting metabolic acidosis.

Biomarkers for differentiation of causes of respiratory distress in dogs and cats: Part 1--Cardiac diseases and pulmonary hypertension.

OBJECTIVE: To review the current veterinary and relevant human literature regarding biomarkers of cardiac disease leading to respiratory compromise. DATA SOURCES: Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent textbooks. HUMAN DATA SYNTHESIS: Cardiac troponins (cTn) and natriuretic peptides are routinely used in human medicine. VETERINARY DATA SYNTHESIS: Although biomarkers should not be accepted in lieu of gold standard diagnostics, they may be useful in directing care in the stabilization process. Biomarkers of congestive heart failure (CHF) include natriuretic peptides, cTn, and endothelin. cTnI is useful in differentiating causes of pericardial effusion, but is unlikely to be useful in differentiating CHF from other causes of respiratory distress. The most extensively studied and promising cardiac biomarker is amino-terminal probrain natriuretic peptide, although a bedside test is not currently available. Other natriuretic peptides have also proven useful, but have lower availability. Endothelin is unlikely to be clinically useful. Although critically evaluated for their use in cardiac diseases, many of the biomarkers are affected by more than one type of respiratory or systemic disease. Several cardiac biomarkers are increased in cases of pulmonary hypertension (PH), but discerning CHF alone from PH or a combination of heart disease and PH is challenging when evaluating biomarkers alone. CONCLUSION: At this time, there are no point-of-care tests for biomarkers that can reliably differentiate among causes of dyspnea of cardiac origin in dogs and cats, although there are reference laboratory tests that show promise and future development of point-of-care tests that may be useful in certain situations.

Biomarkers for differentiation of causes of respiratory distress in dogs and cats: Part 2--Lower airway, thromboembolic, and inflammatory diseases.

OBJECTIVES: To review the current veterinary and relevant human literature regarding biomarkers of respiratory diseases leading to dyspnea and to summarize the availability, feasibility, and practicality of using respiratory biomarkers in the veterinary setting. DATA SOURCES: Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent textbooks. HUMAN DATA SYNTHESIS: Numerous biomarkers have been evaluated in people for discriminating respiratory disease processes with varying degrees of success. VETERINARY DATA SYNTHESIS: Although biomarkers should not dictate clinical decisions in lieu of gold standard diagnostics, their use may be useful in directing care in the stabilization process. Serum immunoglobulins have shown promise as an indicator of asthma in cats. A group of biomarkers has also been evaluated in exhaled breath. Of these, hydrogen peroxide has shown the most potential as a marker of inflammation in asthma and potentially aspiration pneumonia, but methods for measurement are not standardized. D-dimers may be useful in screening for thromboembolic disease in dogs. There are a variety of markers of inflammation and oxidative stress, which are being evaluated for their ability to assess the severity and type of underlying disease process. Of these, amino terminal pro-C-type natriuretic peptide may be the most useful in determining if antibiotic therapy is warranted. Although critically evaluated for their use in respiratory disorders, many of the biomarkers which have been evaluated have been found to be affected by more than one type of respiratory or systemic disease. CONCLUSION: At this time, there are point-of-care biomarkers that have been shown to reliably differentiate between causes of dyspnea in dogs and cats. Future clinical research is warranted to understand of how various diseases affect the biomarkers and more bedside tests for their utilization.

Aspiration pneumonia in dogs: treatment, monitoring, and prognosis.

Aspiration pneumonia and aspiration pneumonitis are associated with significant morbidity in both veterinary and human medicine. A variety of medical conditions and medications can predispose patients to aspiration. Ideally, aspiration should be prevented, but in dogs that develop aspiration pneumonia, close monitoring and supportive care are imperative. This article describes antimicrobial treatment, fluid therapy, ancillary medical therapy, oxygen therapy, and prognosis for aspiration pneumonia.

Aspiration pneumonia in dogs: pathophysiology, prevention, and diagnosis.

Aspiration pneumonia and aspiration pneumonitis are associated with significant morbidity in veterinary and human medicine. A variety of medical conditions and medications can predispose patients to aspiration, and every precaution should be taken to prevent aspiration from occurring. For dogs that aspirate oral or gastric contents and subsequently develop pneumonia, monitoring and supportive care are imperative. This article discusses the pathophysiology, prevention, and diagnosis of aspiration pneumonia.