The consumption of a grape and blueberry polyphenol‐rich mixture is safe in dogs

Abstract

Grape polyphenols have beneficial health effects, but grape ingestion has been associated with acute renal failure leading most often to fatal issue in dogs. The responsible factors are unknown.Our aim was to check the safety of a supplement of polyphenol‐rich mixture (grape and blueberry extracts (specific pet Neurophenols® blend)) in dogs.Seventeen dogs were given, for 12 wks, capsules containing 4 (n=5) or 20 (n=6) or 40 (n=6) mg/kg/d of the polyphenol mixture. Five control dogs were given maltodextrin capsules. Blood and 24‐h urine were taken before the beginning of the study (W0), then after 4 wks and 12 wks of supplementation. Plasma standard analysis (creatinine (Creat), urea, minerals (Na, K, Ca, P), total protein, hepatic biomarkers (ALT, ALP)) were assayed. New biomarkers that reveal early renal damage were measured : plasma and urinary cystatin C (CysC), clusterin (Clu), neutrophil gelatinase‐associated lipocalin (NGAL). Urinary biomarkers/Creat ratios were calculated. Data were compared with limits of reference intervals or with the highest values from our control dogs and experimental dogs at W0.Whatever the week, plasma standard analysis were below high limits of reference intervals. Plasma CysC concentration was below our own high limit. Plasma Clu and NGAL concentrations were below limits of reference intervals. Urinary CysC/Creat, Clu/Creat, NGAL/Creat ratios were below our own limit.Grape extract and blueberry extract (specific pet Neurophenols® blend) consumption was not associated with any sign of renal failure and can be consumed safely in dogs.