Short-Term Renal Effects of Add-On Levetiracetam in Client-Owned Dogs with Idiopathic Epilepsy Receiving...

Levetiracetam (LEV) is commonly used as an adjunctive antiseizure medication (ASM) in dogs because of its favorable pharmacokinetic profile and limited hepatic metabolism. However, because LEV is predominantly eliminated through renal excretion, prospective clinical evidence regarding its effects on renal function in dogs remains limited. This prospective study evaluated short-term changes in renal biomarkers and urinalysis parameters in 12 client-owned dogs with idiopathic epilepsy (IE) receiving concurrent phenobarbital (PB) and adjunctive LEV. All 12 dogs were evaluated at baseline (day 0), day 14, and day 28. Renal assessment included serum symmetric dimethylarginine (SDMA), serum creatinine, blood urea nitrogen (BUN), phosphorus, albumin, and urinalysis; glomerular filtration rate (GFR) was not directly measured. Changes in SDMA over time were analyzed using the Friedman test, whereas serum creatinine, BUN, phosphorus, and albumin were analyzed using repeated-measures ANOVA with the Geisser-Greenhouse correction. No statistically significant changes were detected in SDMA, serum creatinine, BUN, phosphorus, or albumin during the 4-week study period. Urinalysis showed no consistent progressive abnormalities, including proteinuria, glucosuria, or urinary casts. Sedation was the most frequently observed clinical adverse event, occurring in 83% (10/12) of dogs, although it was generally mild and did not require treatment discontinuation. Overall, no detectable short-term deterioration in the assessed renal biomarkers or urinalysis parameters was identified during the 4-week study period in non-azotemic dogs receiving concurrent PB and adjunctive LEV. However, the absence of statistically significant or clinically detectable changes does not exclude subtle alterations in renal function or subclinical renal injury. Larger controlled studies with longer follow-up periods and direct assessment of GFR are warranted.