Grape and raisin toxicity | Dr. Justine Lee

Posted by justinelee in Animal Safety, Blog, Pet Health, Uncategorized

Just had a canine patient ingest grapes, raisins, currants or anything from the Vitus species?

Grapes and raisins (Vitis spp.) have been recently associated with development of acute kidney injury (AKI) with ingestion. All types have been implemented with toxicosis, including organic grapes, commercial grapes, homegrown grapes, and seedless or seeded grapes. Common kitchen items also contain grapes, raisins, or currants in their active ingredient, including raisin bread, trail mix, chocolate-covered raisins, cereal with raisins, etc. Currently, grapeseed extract has not been associated with nephrotoxicity.¹ While the mechanism of how grapes and raisins cause AKI is unknown, there are several suspected hypotheses, including individual inability to metabolize certain components of the fruit (e.g., tannins, high monosaccharide content),¹ the presence of mycotoxins or pesticide residues on the fruit,¹ or salicylate-like chemicals within the grape or raisin.

Treatment for grape and raisin ingestion includes aggressive decontamination as the first-line of therapy. Grapes and raisins seem to stay in the stomach for a prolonged period of time, and are not rapidly broken down or absorbed from the gastrointestinal tract (GIT); hence, delayed emesis induction even several hours post-ingestion can still be initiated to maximize decontamination methods. One dose of activated charcoal can be administered to also prevent absorption of the unknown nephrotoxin. The use of multiple doses of activated charcoal is not indicated at this time. While 1-2 grapes or raisins is unlikely to result in an toxicity issue, more significant amounts should be decontaminated and treated. The majority of ingestions should be treated as potentially idiosyncratic and should be appropriately decontaminated and treated.

Clinical signs of grape and raisin toxicity include:

• Vomiting
• Lethargy
• Dehydration
• Diarrhea
• Inappetance or anorexia
• Abdominal pain (e.g., renal pain, consistent with AKI)
• Halitosis (e.g., uremic halitosis secondary to AKI)
• PU/PD
• Oliguria (which can be seen 48-72 hours post-ingestion)
• Anuria  (which can be seen 48-72 hours post-ingestion)
• Azotemia (which can develop within 24 hours)
• Hypercalcemia
• Hyperphosphatemia

Treatment includes decontamination, aggressive intravenous fluid therapy, anti-emetics, blood pressure and urine output monitoring, and serial blood work monitoring (q. 12-24 hours). In severe cases, hemodialysis or peritoneal dialysis may be necessary. Asymptomatic patients that have been adequately decontaminated and survive to discharge should have a renal function and electrolytes monitored 48-72 hours post-ingestion. Overall, the prognosis is fair to poor, depending on time to decontamination, response to therapy, and prevalence of oliguria or anuria. Overall, 50% of dogs that ingest grapes and raisins never develop clinical signs or azotemia,¹ making the prognosis fair to good.

References:

1. Craft E, Lee JA.  Grapes and raisins. In: Osweiler G, Hovda L, Brutlag A, Lee JA, eds. Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Small Animal Toxicology
   Ed. Iowa City: Wiley-Blackwell, 2010. pp. 429-435.