Putative intestinal hyperammonaemia in horses: 36 cases.

REASONS FOR PERFORMING THE STUDY: Intestinal hyperammonaemia (HA) has been infrequently reported in individual horses; however, there have been no studies describing clinical and laboratory data as well as short- and long-term outcome in a larger number of cases. OBJECTIVES: To describe clinical and laboratory data and short- and long-term outcome in a large group of horses with intestinal HA. METHODS: Multi-centred, retrospective study; case records of horses with HA were reviewed and any horse with a clinical or post mortem diagnosis of intestinal HA was included. Hyperammonaemia was defined as a blood ammonium (NH(4) (+)) concentration ≥60 µmol/l and horses with a diagnosis of primary hepatic disease were excluded. Relevant data were recorded and, if appropriate, data from survivors were compared to nonsurvivors to identify potential prognostic indicators. RESULTS: Thirty-six cases, 26 mature horses and 10 foals with intestinal HA were identified. Case histories included diarrhoea, colic and neurological signs and the most common clinical diagnosis was colitis and/or enteritis. The most common clinical and laboratory abnormalities included tachycardia, increased packed cell volume, hyperlactataemia and hyperglycaemia. Fourteen horses (39%) survived to discharge; NH(4) (+) concentration on admission was the only parameter significantly associated with survival. All surviving horses and foals for which follow-up information was available recovered completely and returned to their intended use without further complications. CONCLUSIONS AND POTENTIAL RELEVANCE: Intestinal HA occurs in mature horses and foals and can be associated with severe clinical and laboratory abnormalities; further studies are required to investigate predisposing factors and delineate possible differences in aetiologies.

Disposition of flunixin meglumine injectable preparation administered orally to healthy horses.

An injectable preparation of flunixin meglumine was administered orally and intravenously at a dose of 1.1 mg/kg to six healthy adult horses in a cross-over design. Flunixin meglumine was detected in plasma within 15 min of administration and peak plasma concentrations were observed 45-60 min after oral administration. Mean bioavailability of the oral drug was 71.9 +/- 26.0%, with an absorption half-life of 0.76 h. The apparent elimination half-life after oral administration was 2.4 h. The injectable preparation of flunixin meglumine is suitable for oral administration to horses.