Grape and Raisin Toxicity
By Dr. Karen Burgess
Picking ripe grapes from the vine is fun for all. But at the same time grapes and raisins can be very dangerous for dogs and possibly cats. The exact mechanism of this toxicity is not understood and a variety of grapes (seedless or not, green or red) have been implicated along with raisins. Even more frustrating is that there is not a specific toxic dose nor are all animals affected equally.
How many grapes or raisins are a problem?
Grape toxicity is not dose dependent, meaning that the amount of exposure does not correspond well to signs of disease or severity. Previous safe exposure to grapes also does not affect a pet’s susceptibility to toxicity. Complete kidney failure has been reported after as little as 0.7 oz/kg grape exposure and 0.11 oz/kg raisin exposure. As an example, 6 grapes weigh approximately 1 ounce. A 25# pound dog can experience complete kidney failure with as few as 40 grapes while a 1 ounce box of raisins could be life threatening for a 20# dog. The toxicity of grape juice and grape jelly are not known so should also be avoided. Grapeseed extract is thought to be safe.
Signs of grape toxicity
The first and only symptoms may be those of gastrointestinal upset (vomiting, diarrhea, inappetance). These symptoms may be present for weeks after ingestion in some cases. In severe cases, potentially fatal kidney failure can occur 12 to 72 hours after ingestion.
What to do if your pet ingests grapes/raisins
Contact your veterinarian, animal emergency hospital, or animal poison control immediately. If ingestion has just occurred, often medication can be given to induce vomiting. Hospitalization for further decontamination, intravenous fluid therapy, and monitoring of kidney values/lab work may also be recommended. If after 3 days there is no sign of kidney disease, the prognosis is typically favorable. In cases of kidney failure, the prognosis is often grave.