Did you know that raisins and currants became popular between the 14th and 16th centuries and were an important part of English cuisine?
Perhaps I am an odd person, but I have always been grossed out by raisins, never a huge fan of grapes, and what in the world are sultanas and currants!
These very popular, healthy fruits seem to be everywhere! They are present in many more things than we often realize.
They can be mixed up with nuts in a trail mix, in bread, in holiday fruitcake, cookies, bagels, or granola bars (this is especially cruel because they look like chocolate chips), and even in a liquid form like wine or juice. All of these presentations are very appealing to our pets.
Why Are Grapes, Raisins, and Currants Toxic to Dogs and Cats?
The Animal Poison Control Center (APCC) first identified the issue of toxicity over a period of a year between 2003 and 2004, when 140 cases were seen. Of the 140 cases, 50 dogs developed symptoms, and 7 died.
Unfortunately, the way in which these fruits cause toxicity is still unknown. It does not appear to matter how they're eaten – in original fruit form or in baking – since most, if not all, products containing them can cause toxicity.
There does not seem to be a connection between the amount consumed and the severity of toxicity.
One study1,2 did estimate that it took more than 3 grams of grapes or raisins per kilogram of pet weight to cause toxicity, but generally, due to the uniqueness of each pet, it can take significantly less or more to create an issue or toxic effects.
Just like other potential toxins, each pet will react differently, and their individual threshold for a toxic dose will be different. The effect on a Chihuahua compared to a Labrador consuming a few grapes, raisins, or currants will be significantly different.
The unknown grape, raisin, and currant toxin can cause the following symptoms:
These signs are typically evident within 6 hours of ingestion but are always present within 24 hours.
- Weakness (including difficulty walking)
- Increased water consumption
- Abdominal pain
- Anorexia (not eating and losing weight)
- Acute severe kidney failure with the possible lack of urine production (can be noticed within 48 hours of ingestion)
- Possible death
If your dog or cat has eaten any quantity of these foods, including those found in baked goods, cereals, or juice, contact a veterinarian or one of the veterinary-specific poison control hotlines immediately for advice.
A case series, reported in 2022 by the Journal of Veterinary Emergency and Critical Care, proposed a possible cause of grape toxicity being related to tartaric acid and its salts since this organic acid is found in high concentrations in grapes.
This theory is based on the fact that 6 dogs exposed to tartaric acid, following ingestion of cream of tartar, tamarind pods, or tamarind paste, developed vomiting within 1 to 14 hours and had elevated kidney values (azotemia) within 18 to 53 hours after ingestion.
Of the 6 dogs, 4 were euthanized and it was found that the kidneys of these dogs had the same changes noted in dogs that had eaten grapes.
The similarities demonstrated between the two is what lead to the proposed mechanism of grape and raisin toxicity being tartaric acid and its salts.
This information will help in ongoing research so that a diagnosis and treatment can be determined.
Treatments for Grape, Raisin, and Currant Poisoning
If it has been within 2 hours of your pet eating the fruit, your veterinarian will generally induce vomiting. It is never recommended to induce vomiting yourself unless instructed to do so by a veterinarian.
Another treatment that may be administered is activated charcoal. The purpose of it is to absorb any potential toxins in the gastrointestinal tract.
This isn't something you should attempt to do on your own unless advised to do so by a veterinarian, as IV fluids are needed to ensure your pet does not develop hypernatremia (elevated blood sodium levels). There is also a risk of aspiration pneumonia and vomiting.
Once seen by a veterinarian, your pet will also be hospitalized on intravenous fluids and monitored for 48 hours. Stomach protectants and medications for blood pressure control may also be administered. During your pet’s hospitalization, blood work will be done to monitor your pet’s kidney function.
For pets that present with symptoms of toxicity, the outcome for recovery is poor. Factors that worsen the chances of recovery are if your pet is weak, has difficulty walking, or has high levels of calcium in their blood.
To prevent your pet from eating these fruits, take the following preventive measures
- Don't intentionally feed any of these foods or food items containing them to your pets. Always read the ingredient list before giving your pet any human foods to be sure there are none of these fruits on the list.
- If you have children, be careful with pets cleaning up after them. Grapes and raisins are common toddler snacks, and toddlers frequently drop what they are eating or want to share their snacks with the family pets. Watch where your kids’ snacks fall, and clean up well when they are done.
- Recognize that grapes, raisins, sultanas, and currants are present in other types of foods, too. They are especially common in cookies (oatmeal raisin) and cereal (raisin bran), as well as bread and granola bars. Be careful what you let your pet eat, and lock up the garbage so they can’t go scavenging.
- Be sure to tightly close all juice containers (give kids grape-containing drinks in spill-proof containers) and wine bottles. If a spill occurs, be sure that your pet cannot lap it up while you are getting cleaning supplies.
Also, do not leave toweling or towels used to clean the mess where your pet may be tempted to eat or chew on them. This could create double trouble — toxin and an intestinal blockage.
If you want to learn more about other safe and unsafe fruits and vegetables, check out the articles listed below. Always remember, when in doubt, don’t give it to your pets!