Why Are Grapes Bad for Dogs?

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According to the ASPCA, both grapes and raisins have been linked to kidney failure in dogs. The cause of the toxicosis is not known. Symptoms within 12 hours of ingestion can include vomiting, diarrhea and lethargy.

While some dogs experience toxicosis from eating grapes and raisins, some do not. Some dogs can eat them without problem but then experience symptoms when consuming them at a later date. With no cause of toxicosis yet identified, dogs should generally not eat grapes and raisins. As symptoms of toxicosis progress, dogs may stop eating and become increasingly dehydrated and lethargic. Dogs also may exhibit more frequent urination followed by an absence of urination as stages progress. Kidney failure may occur as soon as three to four days, but the symptoms and long-term kidney failure can persist when dogs survive the acute intoxication. Immediate veterinary treatment is recommended so that proper urine flow can be enabled and monitored.