Grapes (and their dehydrated form, raisins) can prove extremely toxic to dogs. Even a single grape could prove life-threatening, with the symptoms of poisoning sometimes not immediately apparent. If you suspect that your dog has eaten a grape or food containing raisins, consult an emergency vet immediately. They can evaluate your dog’s health and intervene if necessary.
Why Shouldn’t Dogs Eat Grapes?
There isn’t an exact reason why grapes and raisins can cause gastrointestinal upset and renal failure in some dogs.
“The exact compound in grapes that causes toxicity is unknown. There are several hypotheses, but the exact cause remains unknown,” shares Dr. Jessica Dowling, Medical Director and Emergency Veterinarian at VEG ER for Pets in Henderson, Nevada. “Some dogs are sensitive to grapes, and even a single grape can cause them to become ill. Other dogs can eat grapes regularly without getting sick.”
More than one grape or raisin for every 10 pounds of body weight is sufficient to cause renal failure in some dogs. Still, any dog, no matter their age, breed, or weight, can have negative reactions after eating grapes.
“Avoiding [grapes] in your dog’s diet is the recommended approach,” says Dr. Dowling.
Symptoms of Grape Poisoning in Dogs
Symptoms of grape poisoning can take anywhere from six to 12 hours to develop.
“Depending on the toxin causing your dog’s illness, the symptoms can vary in type and severity,” says Dr. Dowling. “Some dogs only show signs of upset stomach (vomiting, diarrhea) or loss of appetite. Other dogs will become very sick, unable to even sit or stand up. Think of it like a person catching a cold, or another person having the flu.”
Other symptoms of grape-related poisoning include:
- Dehydration
- Tremors
- Abdominal pain
- Lethargy
- Polydipsia (extreme thirst)
- Little or no urine output
- Behavioral changes indicating distress
“Within 24 to 72 hours, dogs can develop detectable signs of kidney injury on blood work. These dogs will appear progressively sicker, becoming dehydrated, refusing food, and becoming more painful and lethargic,” says Dr. Dowling.
Treatment Options for Grape Toxicity
Suppose you suspect that your dog has eaten a grape or raisin. In that case, a veterinarian will evaluate their treatment options based on many factors, including how much they may have eaten and the severity of their symptoms. Dr. Dowling shares another element that may factor into your dog’s treatment plan:
“Your veterinarian will [also] recommend treatments based on how long it has been since the grape was eaten, and if the grape can successfully be removed by making your dog vomit,” she says. “It may be as simple as inducing vomiting, giving some fluids under the skin, and sending your dog home with anti-nausea medication.”
Even if initial bloodwork is normal, it’s highly recommended to re-check kidney values again at 24, 28, and 72 hours to ensure there has been no kidney damage. Many veterinary emergency hospitals may hospitalize patients after grape ingestion, place them on IV fluids for up to three days, and monitor serial blood values while hospitalized to make sure there has been no damage to the kidneys.
Matters change if your dog’s bloodwork reveals abnormalities in their kidney or electrolyte values. In those cases, your veterinarian will likely recommend inpatient treatment, which may include ongoing lab work, intensive care for gastrointestinal symptoms, and IV fluids.
Don’t Attempt to Induce Vomiting with Hydrogen Peroxide
Dr. Dowling shares that, during her years working as a veterinarian, she’s received calls from dog owners in remote areas asking how they can induce vomiting with hydrogen peroxide after their pets have ingested something potentially dangerous.
“For my clients, there are two reasons I do not make this recommendation,” she says. “First, because of the risk of severe lung damage if [your dog] inhales the peroxide while you are trying to pour it into their mouth or give it via syringe. Second, the awful taste makes it very hard to get your dog to swallow enough to induce vomiting.”
There is no better substitute than consulting a veterinarian if you suspect that your dog has eaten something toxic.
“The safest thing for your dog is to visit your family veterinarian (or an emergency veterinarian if it’s after hours) and have a doctor induce vomiting as soon as possible,” recommends Dr. Dowling. “If it has been more than three hours, inducing vomiting will unlikely be helpful, but your dog should still be evaluated and his/her bloodwork checked.”
Alternatives to Grapes and Raisins
If you’re looking to supplement your dog’s meals with fruit (or just offer a tasty snack), you have many options that don’t include grapes or raisins.
“Most dogs enjoy fruits with less citrus in them, [such as] blueberries, raspberries, mango, and watermelon. I would aim for blueberries and watermelon first, because they are low in sugar compared to other fruits. Just like us, extra sugar in the diet puts on the pounds,” says Dr. Dowling.
You can also consider offering one of these other dog-friendly fruits as an occasional treat:
- Fresh peaches with the pits removed
- Bananas, cantaloupe, and strawberries in moderation (as these are high in sugar)
- Oranges with the skin removed
- Apples and pears with the seeds and core removed
Your dog can also safely enjoy many vegetables, from carrots to green beans. Their veterinarian can offer further insight into what dietary changes or additions could promote their health.
Preventing Your Dog From Eating Grapes
Preventing your dog from eating grapes or raisins goes beyond putting these items on a high shelf or behind a cabinet door. It involves a comprehensive approach that, with some time, will feel like second nature. Protecting your dog from eating grapes and other foods hazardous to their health involves:
- Reinforcing household boundaries. If your dog frequently snatches food from countertops, they could accidentally snack on something containing grapes or raisins. Use positive reinforcement to deter this behavior. This training method involves pairing a desired action (such as keeping all four paws on the ground) with a reward, such as praise or a high-value treat.
- Educating members of your household about what your dog can eat. For example, if you have young children, explain what foods are off-limits to your dog. You may implement a rule that your children can only give the dog treats with parental supervision.
- Being mindful of what foods have grapes and raisins. As noted, some foods contain grapes or raisins as added ingredients, such as desserts, bread, and pastries. Understanding the ingredients in certain items can help you know when to put them out of your dog’s reach.
When in Doubt, Consult a Veterinary Professional
If your dog has eaten a grape or raisin, it’s best to seek veterinary attention rather than take a wait-and-see approach. The sooner you seek medical assistance, the more promising your dog’s prognosis could be.
If you live far from a veterinarian or don’t have an after-hours veterinary hospital, you can utilize resources such as the Pet Poison Helpline for 24/7 immediate treatment advice.