Association of the type of metabolic acidosis and non-survival of horses with colitis.

Abstract

BACKGROUND: Metabolic acidosis (MA) is the most common acid-base disorder reported in horses with colitis but its association with survival is yet to be determined. OBJECTIVE: Investigate the types of MA in horses with colitis to determine effects of various anions on fatality rates. ANIMALS AND PROCEDURES: We studied 158 horses with colitis. Horses were classified into 4 groups depending on the anion contributing to MA: i) no MA, ii) lactic acidosis (LA), iii) unmeasured strong ion (USI) acidosis, and iv) hyperchloremic acidosis (HA). RESULTS: Sixty percent (95/158) of horses had no MA, 22% (34/158) had LA, 12% (19/158) had HA, and 6% (10/158) had USI acidosis. The fatality rate of horses without MA was 20% (20/95), whereas the rates for those with LA, USI, and HA were 53% (18/34), 30% (3/10), and 16% (3/19), respectively. Horses with LA were more likely to die or be euthanized than horses without MA (OR: 4.2, 95% CI: 1.83 to 9.72,< 0.001) and HA (OR: 5.9, 95% CI: 1.47 to 24.4,< 0.01). CONCLUSION AND CLINICAL RELEVANCE: Lactic acidosis was the most common type of MA in horses with colitis, and it was associated with non-survival.