Acid base disturbances in naturally occurring feline chronic renal failurepatients

The management goals for chronic renal failure (CRF) in clinical veterinary patients include correcting disturbances that are part of the uraemic synd rome. In doing this, the aim is to improve the quality of life of the anima l and, possibly, prolong survival of the remaining functioning nephrons. Me tabolic acidosis is thought to be an inevitable consequence of the uraemic syndrome in cats that may lead to other electrolyte disturbances and affect s the quality of life of our patients. The aims of this paper are to review the literature on uraemic acidosis relevant to feline practice and to pres ent some preliminary data on the prevalence of metabolic acidosis in natura lly occurring chronic renal failure patients presenting to first opinion cl inics. Venous blood pH, bicarbonate and total CO2 concentrations were measu red in blood samples obtained from ferry two cases of CRF and twenty two ag e-matched normal cats. Fourteen (33.3 %) of the cases had venous pH values below 7.283, ten of which were classified as being in severe renal failure (plasma creatinine concentrations > 400 mu mol/l). Five of Six cases that s howed a significant deterioration in their renal function during the course of the study developed metabolic acidosis as a result. Urine pH values wer e significantly lower in moderate and severe renal failure cases (plasma cr eatinine concentration > 250 mu mol/l) when compared with mild renal failur e cases and age-matched control animals. These data suggest that in natural ly occurring feline CRF, patients are able to compensate for their reduced renal function to maintain relatively normal venous blood pH and plasma bic arbonate concentrations and that metabolic acidosis is only evident when th ey reach the later stages of their disease.