Grapes are toxic to dogs primarily because they contain tartaric acid, a type of organic acid that dogs cannot effectively metabolize. This accumulation of tartaric acid in their bodies can lead to acute kidney failure. Not all dogs are affected the same way; some may be more sensitive, and even small amounts of grapes or raisins can cause serious kidney damage, vomiting, diarrhea, lethargy, and other symptoms. The toxicity appears in both the flesh and skin of grapes, and raisins (dried grapes) are often even more dangerous due to the concentration of toxins. Because the exact toxic dose varies and some dogs may suffer severe consequences, it is safest to avoid giving any grapes or grape- derived products to dogs altogether. Additionally, grapes can pose a choking hazard due to their size and shape. The bottom line is that grape toxicity can cause vomiting, diarrhea, excessive thirst, kidney damage, and potentially fatal kidney failure in dogs due to the tartaric acid content, which dogs are particularly sensitive to and cannot easily eliminate from their bodies.
