Yes, it’s true. Raisins and grapes can cause severe health problems when ingested by your dog. The toxic mechanism is unknown at this time. It is unclear whether the risk of problems is the same with cumulative doses as compared to a large, single ingestion. It is also uncertain whether some dogs are more predisposed to having toxicity from grapes or raisins. It is known that 4 pounds of grapes equal about 1 pound of raisins, so fewer raisins need to be ingested to reach toxic levels. In 2004, the Animal Poison Control Center (APCC) reported 50 cases of dogs exhibiting problems ranging from vomiting to life-threatening kidney failure, which results in some deaths after ingestion of varying amounts of raisins or grapes.
Clinical signs start within the first few hours as vomiting and loss of appetite. Within 24 hours, symptoms can progress to lethargy, diarrhea and abdominal pain. The concern for renal failure during the first 72 hours is great. If the kidney enzymes are normal after 3 days, it is unlikely that renal failure will develop. Even if the kidney enzymes are normal at the 3-day period, a repeat blood test 5-7 days later is still recommended.
Diagnosis is most easily made by visualization of partially digested grapes or raisins in the vomit, feces, or both. Noticing that your dog is eating grapes or got into a box of raisins. In addition to visualizing the grapes or raisins the kidney enzymes may become elevated along with the calcium and phosphorus levels.
Treatment must be administered quickly and aggressively for a dog to survive. The sooner treatment is administered, the better the prognosis. Dogs may need to be treated up to three weeks post ingestion. Treatment begins with decontamination of the gastrointestinal tract. Vomiting should be induced as soon as the possible after the ingestion of the grapes or raisins. Next, activated charcoal is given to try and bind the toxins within the grapes or raisins. Administration of intravenous fluids in a 24-hour care facility for 3- 21 days depending on symptoms and blood tests is imperative. Some dogs even need hemodialysis to survive. Many dogs do not survive if the problem is not noted right away.
If your dog has ingested grapes or raisin, contact your veterinarian immediately.
The ASPCA and APCC have advised that grapes and raisins not be given to pets in any amount.