To investigate the effects and duration of orally administered prednisolone on renal function evaluated by glomerular filtration rate (GFR) determination and creatinine (Cr) and symmetric dimethylarginine (SDMA) concentrations as well as on urinalysis, electrolytes, and hydric status in healthy dogs.
14 healthy Beagles.
In this prospective double-masked placebo-controlled study, dogs were randomized after baseline evaluation to receive a 7-day course of either prednisolone (1.5 to 2.0 mg/kg, PO, q 12 h) or a placebo. A repeated-measure design was performed, each dog participating in 4 successive sampling sessions. Clinical data, systolic blood pressure, CBC, and biochemical analyses including serum SDMA concentration, GFR determination, urine output quantification, and complete urinalysis were performed for all dogs the day before (D0) and at the end of steroid administration (D7) as well as 2 weeks (D21) and 4 weeks (D35) after the end of treatment.
At D7, when compared with baseline, GFR increased significantly in treated dogs, whereas creatinine and SDMA concentrations decreased significantly. GFR and Cr but not SDMA modifications persisted significantly at D21. None of the variables differed significantly from baseline at D35. The OR of presenting an albumin band on urine electrophoresis was 2.4 times as high in treated versus control dogs (OR, 36; 95% CI, 1.8 to 719.4; P = 0.02).
A short-term course of immune-suppressive prednisolone treatment in healthy dogs leads to a sustained but reversible renal hyperfiltration state. Modification in electrolytic variables can affect the clinical interpretation of blood work in such patients.