For many years, the specific toxic compound responsible for the harmful effects of grapes and raisins was unknown. Why some grapes are toxic and others not stumped veterinarians and toxicologists.  All species from the Vitis species have potential for harmful effects. Those ingredients include grapes, raisins, and currants. Any food containing these fruits may also be harmful.

Scientists puzzled over why some grapes were toxic and others were not.  Why some people could use raisins as training treats with no issue and another dog could break into the pantry and eat raisins and be affected.

Although many of these questions remain, scientists are finally honing in on what the toxic principle is and this blog post should walk you through our current understanding so that you have an action plan should your pet run into a potential issue with grapes.

Why are raisins, grapes, and currants toxic?

A recent study has identified a compound called tartaric acid as the culprit. Researchers found that the amount tartaric acid present in grapes can vary widely, and not all grapes are equally toxic. Tartaric acid contributes to the characteristic tartness or sourness of these fruits. However, the exact levels of tartaric acid can vary depending on the grape variety and the ripeness of the fruit.

In general, grapes and raisins that are more acidic tend to have higher levels of tartaric acid. Tartaric acid levels are often influenced by factors such as grape variety, growing conditions, climate, and post-harvest handling. The taste and tartness of grapes and raisins can also vary based on these factors.

Not only is the question as to which grapes would be problematic, it's also misunderstood which pets will have serious complications from eating just a few grapes. Scientists have compared organic, pesticide treated, seedless vs. seeds, white or red, etc. and could not hone in on the toxic principle.  

Is Grape seed extract toxic to pets?

Grape seed extract is not toxic to pets.

What About Grape Juice and Wine?

The current recommendation is to avoid grape juice and wine as well.

What Are The Signs & Symptoms Of Grape Toxicity In Dogs?

Dogs will typically vomit within a few hours of eating the grapes. Grape skins and remnants may be in the vomitus. This is a big heads up to go straight to the veterinarian as doing so can save their life.

Some dogs will then go on to becoming lethargic, stop eating, and can have abdominal pain.

These symptoms can go on for days to weeks.

How is grape/raisin poisoning diagnosed?

Within 24 hours blood work may indicate that the kidneys have been affected by grape ingestion. Your veterinarian can perform diagnostic tests such as an entire blood sample (CBC), a blood biochemical analysis, and urine testing to determine this while action is taken to support the kidneys and prevent further damage.

Blood work often shows elevated blood calcium, blood urea nitrogen, creatinine, and phosphorus. As the damage to the kidneys progress some pet swill produce less urine due to kidney damage. Unfortunately, even with intervention, some pets will die from exposure to grapes, currents, or raisins.

How is this poisoning treated?

Treatments have an objective of blocking the absorption of toxins and preventing or minimizing kidney damage. Ideally, dogs should be treated immediately with inducing vomiting and using activated charcoal. Using this method helps stop the absorbed toxin circulating in stomachs. Since grapes and raisins stay on our stomachs for a longer time it is important to induce vomiting at any time. Afterwards, decontaminated kidneys will be treated and may need aggressive intravenous fluid to help maintain/protect their function.

What do I do if my dog eats a grape?

If your pet eats grapes, it is essential to take immediate action to ensure their safety. Grapes and raisins can be toxic to dogs and some other animals, even in small quantities. First, contact your veterinarian or an animal poison control hotline right away for guidance. They will provide you with specific advice based on your pet's size, the amount of grapes consumed, and the time frame that they have consumed the grapes.

The lowest recorded amounts that caused ARD are:

• Grapes: 0.7 oz/kg, 80 grapes weigh a pound so a 20 pound dog could eat 1/2 pound or 40 grapes or less and have serious issues.

•  Raisins 0.11 oz/kg. A small box of raisins is 1 ounce and this could pose a significant problem for a 20 pound dog.

Small doses can be a problem too. Unfortunately, other than eating raisins, it's unknown what makes some patients more susceptible.

Dog Has Eaten Grapes And IS Showing Signs Of Illness

In such situations, a great deal more effort must be required to prevent your dog from experiencing permanent renal problems. Your animal may need medical treatment which includes fluids to support the kidneys.

What if my dog eats a grape but seems fine?

Usually a dog or cat will start vomiting within 2-24 hours. Do no wait to see what happens if you are unsure, or think it's been awhile, they might be o.k. Pets can benefit from decontamination even after 8-12 hours after ingestion. Call your veterinarian for guidance. If it's after hours call an emergency clinic. Anyone can call the National Animal Poison Control and get help.

ASPCA Animal Poison Control Center Phone Number: (888) 426-4435

https://www.aspca.org/pet-care/animal-poison-control

Why Are Some Dogs Fine After Eating Grapes Or Raisins?

Presently it is not possible to determine what grapes and raisin fruit' s toxic profiles are and how susceptible a particular puppy can to this toxine can be to this. Typically, some dogs eat grape juice or other raisins without any adverse effects but others may suffer from acute kidney failure.

What Is The Prognosis After Grape Ingestion?

As with most medical conditions the prognosis is varied. In general prognosis is generally related to the degree of kidney damage they have suffered. Timely intervention improves the chance of a recovery with decontamination and support of the kidneys with fluid therapy. An integrative veterinarian can prescribe supplements to help kidney function in recovery post exposure.

How can I prevent this problem?

Unfortunately, many pets will die even with treatment if there is substantial damage to the kidneys. Knowledge is power, and as a veterinarian I feel those that dealt with the problem straight away had good outcomes. More times than I can say, people will brush their concerns under the rug thinking how could just a few grapes cause a problem (not to mention the problem with your pocketbook when it comes to emergency care).

To keep your pets safe, it's important to keep grapes and raisins out of reach of pets and to be cautious when giving your pet any human food. It's also important to monitor your pet's behavior and health, and to seek veterinary care promptly if any unusual symptoms or behaviors are observed.

Preventative care always helps compared to cure. Keep cranberry and grapefruit cake, hot cross bread and Christmas mince tarts out of your dog. Do nothing when you have dogs who have been asking you to feed them their begging eyes. Keep watch over your kids if they have eaten boxes of raisins, and clean them immediately. Keep a vigilant eye on everything. Checking ground for raisins can cause a dog to become annoyed when a child spills a cup into a bowl or spills them onto the ground.

Avoid Those Grapes of Wrath!

In conclusion, grapes and raisins can be toxic and potentially life-threatening to dogs and cats. While the exact reasons for the toxic effects are not entirely clear, it's important to keep these foods away from pets and to seek veterinary care if ingestion is suspected. As always, prevention is key, and pet owners should take care to keep their pets safe by avoiding feeding them potentially harmful human foods and following safe feeding practices.