A recent review of studies published in the journal Frontiers in Veterinary Science by two Italian researchers at the University of Milan found that several typical human foods were frequently involved in the inadvertent poisoning of pets, particularly dogs.
The researchers, Cristina Cortinovis and Francesca Caloni, noted that cats can also be sickened, but “dogs are most commonly affected because of their indiscriminate eating habits.” (Translation: Dogs will eat anything; cats are more finicky.)
In general, the researchers wrote, “the poisoning episodes resulted from a lack of public knowledge of the health hazard to small animals that may be posed by these products.” Either owners fed their pets the foods, unaware of the danger, or the animals themselves accidentally got ahold of them.
While some foods, like chocolate, have been known for a while to be bad for cats and dogs, “others such as grapes had previously been considered unlikely to cause problems and have emerged as a potential concern only in the last few years,” the researchers said. The growing use of the artificial sweetener xylitol in several products has also posed a recent risk.
Carmela Stamper, a veterinarian at the Food and Drug Administration, recently warned pet owners about human foods that could sicken their dogs, including fried and fatty foods and too many salty snacks. “Our bodies may break down foods or other chemicals that a dog’s can’t tolerate,” she said in a statement.
Here are the five common foods that cause the most pet deaths and illness:
Grapes and their dried products (raisins, sultanas and currants)
Grapes, both fresh and dried (raisins, sultanas and currants), can cause kidney failure in dogs, although some dogs are more susceptible than others, the review found.
For example, some dogs ate up to 2 pounds of raisins without any life-threatening effect, while others died after eating just a handful. Kidney failure was reported in a dog weighing about 18 pounds that ate only four to five grapes. Given this wide range of reactions, dogs that eat any amount of grapes or raisins should be taken quickly to a veterinarian.
Artificial sweetener xylitol
The artificial sweetener xylitol is used in sugar-free gum and other sweets and baked goods, as well as in a number of dental care products, because of its antibacterial properties.
As its use has spread, so have reports of severe, life-threatening problems in dogs that ate foods that contained the sweetener. Xylitol, the researchers explained, causes a “dramatic decrease in blood glucose levels” in dogs. It also has been associated with liver failure.
Symptoms of xylitol poisoning can occur within 30 to 60 minutes of ingestion, but they also may occur up to 12 hours later. Symptoms begin with vomiting and can worsen to lethargy, collapse and seizures.
A recent study reported 192 cases of xylitol poisoning in dogs from 2007 to 2012. All the dogs survived, thanks to prompt veterinary care, researchers noted.
Onions and garlic
Onions, garlic, leeks and chives — all members of the genus Allium — can make dogs and cats very sick. The plants contain a compound that, when eaten, cause a pet’s red blood cells to break down. Even a small amount can cause this dangerous change, and the toxic effects will occur whether the onions or related foods are raw, dried or cooked.
According to the review, there were 69 cases of dog poisoning and four cases of cat poisoning between 1994 and 2008 from eating a wide range of Allium-containing foods — everything from baked garlic to onion soufflé to Chinese dumplings containing chives.
People should be aware that symptoms can occur a day or several days after the incident, depending on how much their pet ate.
Chocolate, caffeine and coffee
Chocolate may have health benefits for humans, but not so for animals. The sweet treat is among the 10 most common reasons for poisoning in dogs in recent years, according to reports from Animal Poisons Control Center and the American Society for the Prevention of Cruelty to Animals.
Chocolate contains both caffeine and theobromine, both compounds found in cocoa seeds, which can affect both the central nervous system and heart muscles. Symptoms occur two to four hours after ingestion and can range from upset stomachs to seizures and death.
“Poisoning episodes frequently occur around holidays,” when there are more chocolate products in the home, the researchers wrote. Unsweetened chocolate and cocoa powder contain the most theobromine; white chocolate contains the least.
People love macadamia nuts for snacking or in baked goods or candy, but the nuts can be toxic for dogs. According to the review, it’s unclear how much a dog needs to eat to get sick, but some studies indicate that as little as a quarter of an ounce for every 2.2 pounds a dog weighs is enough to result in poisoning.
No deaths have been reported to date, and most dogs recovered within 24 to 48 hours with veterinary care, the analysis found, but pet owners should take care to keep these nuts (or cookies that contain them) away from their pooches.