title: The effect of heart disease, heart failure and diuresis on selected laboratory and electrocardiographic parameters in dogs.
abstract: OBJECTIVE
  To evaluate the influence of heart disease and heart failure on 9 parameters: the serum sodium, potassium, chloride, creatinine and urea concentrations, heart rate, vaso-vagal tonus index (VVTI), red cell number and hematocrit.
  
  
  BACKGROUND
  Previous studies have demonstrated that heart disease, heart failure and their treatment are associated with changes in laboratory and electrocardiographic parameters.
  
  
  METHODS
  Data were retrieved from 92 client-owned dogs with naturally occurring heart disease. Dogs were classified according to the severity of their heart disease and or the presence of heart failure. The effects of heart disease, the progression into heart failure, the initiation of successful therapy and the administration of diuretics on these parameters were determined.
  
  
  RESULTS
  Worse heart failure was characterized by the following changes: a significant fall in serum sodium and chloride concentrations and VVTI, and a significant increase in the serum urea concentration and heart rate. The onset of heart failure was characterized by a fall in VVTI and chloride concentration. The successful treatment of heart failure was characterized by a fall in heart rate, an increase in creatinine and sodium concentrations. Dogs receiving diuretics had higher heart rates, lower VVTI, higher urea concentrations, lower potassium, sodium and chloride concentrations.
  
  
  CONCLUSIONS
  Numerous complex alterations in some of the studied parameters are associated with heart disease, heart failure and their treatment. Further consideration of these changes may improve our skills in diagnosis, prognostication and treatment.
authors.affiliation: The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK.
authors.forename: Adrian
authors.initials: A
authors.lastname: Boswood
authors.forename: Amy
authors.initials: A
authors.lastname: Murphy