Plasmatic L-lactate in pet rabbits: association with morbidity and mortality at 14 days.

Background: The clinical relevance of plasmatic L-lactate concentration (PLLC) is unknown in rabbits. Due to an entirely different metabolism of lactic acid, PLLC in rabbits can reach much higher concentrations than in other species.

Objectives: The aim of this study was to establish a reference interval (95% RI) for venous PLLC in pet rabbits and to assess its diagnostic and prognostic significance in ill pet rabbits.

Methods: Plasmatic L-lactate concentration was determined by an enzymatic colorimetric method. In the first study, healthy rabbits (n = 140) were the control group. The ill rabbits group (n = 405) included the deceased (n = 108) and the survivors (n = 266), depending on the outcome at day 14. In a second study, variation in the PLLC was determined in 25 boarding (control-serial), 99 hospitalized (deceased-serial [n = 27], and survivors-serial [n = 72]) rabbits sampled at 0, 12, 24 and 48 hours.

Results: The 95% RI for PLLC in controls was 2.1-15.2 mmol/L. On-arrival PLLC in ill rabbits was not statistically different from those in the control group, but was significantly lower in deceased compared to survivors or controls. The range of PLLC variation differed significantly between control-serial, deceased-serial, and survivors-serial groups. A better prognosis was associated with an increase of 3.3 mmol/L PLLC within 48 hours after arrival.

Conclusions: Contrary to the available information in other species, morbidity and mortality is associated with sustained low PLLC in pet rabbits, while a good prognosis is associated with an increase in PLLC. Monitoring PLLC in hospitalized rabbits is advisable.