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Emergency data collection from PCV, total solids, blood glucose, blood gas analysis, lactate, BUN, creatinine, and electrolyte levels is critical for rapid metabolic assessment of the patient. This information will aid in identifying the underlying cause of acute abdomen and may help guide initial treatment.

PCV and total solids measurements should always be assessed together. These values will be increased in a parallel manner in cases of dehydration, and will be decreased in a parallel manner in the case of hemorrhage. It is important to note that PCV and total solids may in fact be normal in cases of acute hemorrhage before fluid replacement. A normal PCV with decreased total solids indicates protein loss, but can also be found in the acute phase of hemorrhage when splenic contraction slows the decrease in PCV compared with total solids, or it may also be supportive of peritonitis, which causes increased vascular permeability and leakage of proteins [6].

Blood glucose levels can be measured with a cage‐side glucometer, with hypoglycemia (blood glucose < 60 mg/dl) often associated with sepsis. Hyperglycemia instead may be found in patients with diabetes, or transiently in cases of severe acute pancreatitis or severe stress.

Venous blood gas analysis provides insight into the pH and the metabolic side of an acid–base equation and may also include electrolyte status of the patient. Hypochloremic metabolic alkalosis is a common finding in animals with vomiting, due to pyloric or proximal duodenal obstruction [7]. Animals with severe hypoperfusion may instead show evidence of metabolic (lactic) acidosis.

Patients with urinary tract obstruction or rupture are often hyperkalemic, which is dangerous due to its effects on the heart. Bradyarrhythmias, characterized by a prolonged P–R interval, widening of the QRS complex, increased T‐wave amplitude, and loss of P waves, can eventually progress to atrial standstill and asystole if untreated. Aggressive medical treatment with intravenous fluids and calcium gluconate (20–60 mg/kg administered over 1–3 minutes with concurrent ECG monitoring) is indicated if ECG changes are significant. These patients should be monitored closely with ECG during and after treatment. Dextrose (0.5 g/kg) and regular insulin (0.1 iu/kg) may also be used to drive potassium intracellularly. Bicarbonate will result in a redistribution of potassium to the intracellular space and will also help manage metabolic acidosis. Bicarbonate therapy is generally reserved for patients with severe hyperkalemia coupled with life‐threatening metabolic acidosis (pH < 7.2).