Table 3:

Common acid-base disorders seen in small animal patients and the underlying causes

Acid-base disturbancepHPrimary disorderCompensationDifferential diagnosis
Respiratory acidosisDecreasedIncreased PCO2Increased HCO3 or base excessHypoventilation (upper airway obstruction, anaesthetic drugs, neuromuscular disease, etc)
Respiratory alkalosisIncreasedDecreased PCO2Decreased HCO3 or base excessHyperventilation (fear, pain, anxiety, hypoxaemia, anaemia)
Metabolic acidosisDecreasedDecreased HCO3 or base excessDecreased PCO2Lactic acidosis, ketoacidosis, uraemic acidosis, toxins (ethylene glycol, metaldehyde, salicylates, etc)
Metabolic alkalosisIncreasedIncreased HCO3 or base excessIncreased PCO2Vomiting, diuretic therapy
  • PCO2 Partial pressure of carbon dioxide in the blood, HCO3 Bicarbonate