Can a dog be poisoned by grapes?
According to some authors, eating just a few grapes can lead to the death of a small dog.
There is a widespread belief among dog owners that grapes and raisins are dangerous and that eating them can cause kidney failure in dogs. Admittedly, I have not been able to find any hard evidence for this: I have studied several reputable publications and found no direct ban on the consumption of grapes or raisins. This, in my opinion, is quite strange, because, for the last few years, many reputable authors of articles on animal nutrition have confidently included these berries in the list of banned foods.
One could explain the discrepancy by the appearance of some modern data, if it were not for one "but": most of those who write about the dangers of grapes either say nothing about the reasons for their high toxicity or give completely different reasons. Some mention hydrocyanic acid supposedly contained in seeds, and others refer to the excessive sugar content, but no one provides any scientific reasoning for their position.
I wanted to find out why grapes are called dangerous for domestic dogs if their wild relatives eat them in large quantities without any negative consequences. Take California coyotes, for example, they are omnivores, and grapes are an important part of their diet - along with melons, apricots, plums, and cherries. So what's wrong with grapes? Perhaps the only sensible answer comes from experts at the Animal Poison Control Center (ASPCA).
According to a letter recently sent on behalf of the ASPCA to the editor of the Journal of the American Veterinary Medical Association, tartaric acid in grapes appears to be a danger.
According to the Center, it is the tartaric acid that makes grapes toxic to dogs. Not all and not all animals equally, of course: the authors of the letter point out that the acid content of berries can vary quite a bit depending on the species, method of cultivation, and degree of maturity. Given this fact, and the individual characteristics of each organism, it is easy to explain why, after eating the same amount of grapes, some dogs are severely poisoned, while others look perfectly healthy.
Since it is still not entirely clear whether tartaric acid is the main culprit and which doses are considered dangerous for dogs, the ASPCA is very cautious about making conclusions. In their letter, they emphasize that their findings are only preliminary and insist that more research is needed. Nevertheless, if the danger is confirmed, the blacklist may include not only grapes and raisins but also those products that contain tartar, which is a derivative of tartaric acid, which is known to be widely used in cooking - for example, in the manufacture of meringues.
Any certainty is better than the unknown. Until all the details are more precise, the letter's authors strongly recommend that owners carefully study the composition of dog treats and refrain from feeding their pets grapes in any form or foods that may contain tartaric acid or tartaric stone. They may be right about that: arguing about health, as they say, can be expensive. My dog can live without a raisin bun.