A 2-year-old Friesian mare was examined because she had been sluggish
For a few weeks. Blood biochemistry showed that concentrations of crea
tinine (136 mu mol.L(-1)) and urea nitrogen (6.1 mmol.L(-1)) in plasma
were within their normal limits. Severe metabolic acidosis was appare
nt; the venous pH was 7.154 and the bicarbonatr: concentration was 13
mmol.L(-1). The base excess amounted to -15.3 mmol.L(-1) and the venou
s pCO(2) measured 5.1 kPa. Plasma sodium was normal (135 mmol.L(-1)) a
nd plasma chloride(113 mmol.L(-1)) was slightly elevated, but there wa
s a hypokalaemia (2.9 mmol.L(-1)). The urine had a specific gravity of
1.030 and a pH of5. These findings indicated type 2 renal tubular aci
dosis. The blood values returned to normal 3 days after treatment with
sodium bicarbonate as a 4.2 per cent solution (3.2 mol in total) and
additional bicarbonate (125 g) and potassium chloride (100 g) administ
ered orally.