For a long time, it was not known how harmful grapes and raisins were to dogs. In recent years, it has been reported that grapes and raisins can be poisonous to dogs, even causing fatalities if treatment is not instituted. This article will discuss how to identify grape and raisin toxicity, the clinical signs seen, the treatment available, how to prevent exposure to these potentially hazardous foods, and safer alternatives.

What Is Grape and Raisin Toxicity?

Years ago, the ASPCA's Animal Poison Control Center (APCC) created a database called the APCC AnToxTM database. This is a computerized system that contains about 500,000 animal-related medical conditions. This database allows veterinarians to quickly identify toxic-substance exposures, recognize clinical signs and administer proper treatment. APCC has been able to track cases in this registry, similarities in animal medical conditions nationwide can be logged, and syndromes can be identified.

In 1999, the APCC started noticing a trend in dogs who had eaten grapes or raisins. Nearly all of the dogs developed acute kidney failure. As more cases were reported, enough data was generated in the database to help veterinarians identify and treat dogs at risk. In all of the cases, the ingredients for potential acute kidney failure were the same, grapes and raisins. It didn't seem to matter where the grapes or raisins came from, they all caused the same problem. Also, the amount ingested was variable, and the cases weren't from any specific area, but were all reported in the United States.

It is not known what makes grapes and raisins toxic to dogs. Suspect grapes and raisins have been tested for pesticides, heavy metals such as zinc or lead, and fungal contaminants. Tod date, these elements have not found to cause grape and raisin toxicity. In the cases where grapes were grown in private yards, it was confirmed that none of these products were used.

Warning If your dog has ingested grapes or raisins, no matter the amount, seek veterinary attention immediately!

Symptoms of Grape and Raisin Ingestion in Dogs Vomiting

Diarrhea

Anorexia

Lethargy

Abdominal Pain

Dehydration

Increased water intake

Tremors

Decreased production in the volume of urine (Oliguria)

No urine production (Anuria)

Most affected dogs will develop vomiting and/or diarrhea within six to twelve hours of ingesting grapes or raisins. Other signs include lethargy, anorexia, abdominal pain, weakness, dehydration, polydipsia, and tremors. Labwork will reveal elevations in kidney enzyme levels very early on. There may also be increases in serum glucose, liver enzymes, pancreatic enzymes, serum calcium, or serum phosphorus levels. If left untreated, Oliguric or anuric kidney failure will develop within 24 to 72 hours of exposure. Once the kidneys stop producing urine, the prognosis is grave and most dogs either die or are humanely euthanized.

Treatment

Gastrointestinal decontamination should begin promptly following ingestion. Induction of vomiting will be performed initially followed by the administration of activated charcoal, which binds the toxin and removes it from the body. When large amounts of grapes or raisins have been ingested within 12 hours, or in cases where vomiting and/or diarrhea have spontaneously developed, aggressive fluid therapy for a minimum of 48 hours is recommended. Kidney function and fluid balance are monitored during fluid administration. Dogs that are not producing much urine may be stimulated to produce more with certain medications. Dogs that have no urine production are unlikely to survive unless peritoneal dialysis or hemodialysis is performed. Even in this case, the prognosis is guarded.

Prevention

Educating everyone in the household on the dangers of grapes and raisins is crucial. Watch your dog very closely on walks, to make sure they don't pick up things that can pose a health risk. Don't allow others to give your dog treats that you do not approve of. Keep your dog away from food items containing grapes or raisins, like granola bars, trail mix, and smoothies with grapes.

Safer Alternatives

There are a few fruits that your dog can safely eat:

Bananas (frozen bananas may cause less mess)

Apples (make sure to remove the core)

Raspberries

Before changing your dog's diet, please check with your veterinarian to make sure this is appropriate for their overall health.

References