Kidney Failure in Dogs from Eating Grapes
GRAPES & RAISINS:
The forbidden fruit
Grapes and raisins seem like such innocent little sweet treats but to our dogs they can be deadly. They can cause the kidneys to stop functioning (acute renal failure-ARF).
Exposure to grapes can occur in various ways: off the vine, on the ground, “stolen”, wine processing, etc. For many years dog owners used grapes and raisins as training aids.
At this time, the exact mechanism of the toxicosis involved is unknown. Researchers do not know if chronic, long term ingestion of grapes/raisins causes the same type of problems as a single, large ingestion. Various sources of grapes have been examined (grocery store, backyard, winery, seedless, seeded) without reaching any conclusive associations with toxicity. The grapes were found to be free of pesticides, heavy metals and mycotoxins (fungus toxins). It is unclear if the skins must be ingested for the toxicosis to occur because grape-seed oil appears to be safe.
What actually happens to the dog’s kidneys is unknown. In technical jargon, it could be a metabolic disruption, a nephrotoxic mycotoxin or an idiosyncratic reaction.
Since the mechanism of action is unknown, all cases of grape and raisin ingestion should be considered serious and immediate medical attention is needed. The initial clinical sign is vomiting which will occur within 2 hours of the ingestion. Diarrhea, excessive water drinking, and loss of energy will be noticed around 5 or 6 hours after the ingestion. The remaining signs of ARF (loss of appetite, depression, abdominal pain, tremors and shock) will occur 24 hours or later after the consumption of the grapes.
The diagnosis of grape/raisin toxicosis is similar to ethylene glycol (anti-freeze). Chemistry profiles and clinical signs are used to evaluate the function of the kidneys.
Treatment depends on the animal’s condition on presentation. With acute ingestions, first 2 hours, emesis and activated charcoal are an important part of the treatment plan to eliminate the toxic material. After the 2 hour window, emesis is less likely to be effective. IV fluids for the first 48 hours are used to increase the excretion of the toxin through the kidneys and to increase the filtration rate of the kidneys. A large variety of medications may be used to improve kidney function and to improve survival.
The prognosis is variable and dependent on many different factors. The condition of the dog on presentation, success of decontamination and progression of clinical signs all help determine the outcome of grape or raisin ingestion.
This information is provided for educational purposes only. If you suspect your puppy has a health problem, please consult your veterinarian.
Ó 2005 BKramerDVM 2/3/06