Did you know that grapes and raisins/sultanas (i.e. dried grapes) are toxic to dogs? Grape and raisin ingestion causes acute kidney (renal) failure in dogs, but we still do not know exactly how and why this occurs.
The type of grape (red or white) and whether its store bought or home grown does not seem to matter. It appears to be the flesh of the grape that holds the unknown toxin (i.e. seedless grapes and peeled grapes are still toxic).
Toxicity generally depends on the individual animal rather than their size, age or breed. Even small amounts (i.e. a couple of grapes) can be toxic for some dogs while other dogs can ingest relatively large amounts without developing obvious symptoms.
Signs of grape or raisin toxicity to watch out for:
Loss of appetite
Oliguria (only passing a very small amount of urine)
Anuria (not passing any urine at all)
Sometimes owners visualise grapes or raisins in the vomitus or faecal material.
If you see your dog eating grapes, immediate treatment is required. The vet will induce vomiting depending on the time of ingestion to reduce the chances of toxicity. Further treatment and supportive measures will be discussed by your vet.
This includes intravenous fluid therapy to help protect the kidneys, and providing oral treatments of activated charcoal to help reduce absorption of the toxic metabolites. Follow up blood tests will be performed to assess the health of the kidneys to determine if kidney damage is present.
Keep raisins and grapes out of reach of your dog, as dogs will ingest almost anything. Make sure that all family members are aware of the toxic capacity of grapes (as well as other foods that have been found to be poisonous to pets, such as chocolate, onions, garlic, xylitol containing foods etc.). If you do discover that your dog has ingested raisin or grapes, acting immediately gives your dog the best chance at survival.