Why Is Chocolate Bad for Dogs?

iStock
iStock

Chocolate is toxic to dogs and a number of other animals because it contains alkaloid chemicals called methylxanthines - namely, theobromine (3,7-dimethylxanthine) and caffeine (1,3,7-trimethylxanthine). Both of these stimulate the nervous and cardiovascular systems. It’s an effect that humans seek out, and we can get away with it because we metabolize the chemicals relatively quickly. Other animals process them more slowly, so the effects are more pronounced.

If a dog eats too much theobromine and caffeine, they’ll start to show a number of symptoms, including diarrhea, vomiting, muscle spasms, excessive panting, hyperactive behavior, seizures and dehydration. They may become hyperthermic, go into respiratory failure or experience cardiac arrhythmia, all of which can cause death.

So, how much chocolate is too much for a dog? Depends on the size of the dog, and the kind of chocolate. The amount of methylxanthines in chocolate varies among different chocolate products and brands. In general, though, dry cocoa powder has the most, with around 800 milligrams per ounce, according to the Merck Veterinary Manual. Unsweetened baker’s chocolate (~450 mg/oz), semisweet and sweet dark chocolate (~150-160 mg/oz) and milk chocolate (~64 mg/oz) follow.

Based on their experience and research, the ASPCA Animal Poison Control Center considers 100 to 200 milligrams of methylxanthines per kilogram of dog to be a lethal dose. Mild symptoms can happen with doses as small as 20 mg/kg and severe symptoms, including seizures, can happen at 40-60 mg/kg. Given those numbers, as little as four ounces of dark chocolate could cause problems for a average-sized, 60lb Labrador Retriever, America’s most popular breed. How much chocolate can your dog handle before trouble starts? National Geographic has a handy calculator to figure out the amount based on your dog’s weight and the type of chocolate.

If a dog does eat a toxic dose of chocolate, there’s not much that can be done for it outside of a vet’s office if the methylxanthines make it into the dog’s bloodstream and start circulating through the body. In her book, Help!: The Quick Guide to First Aid for Your Dog, veterinarian Michelle Bamberger recommends slowing or stopping this process by the body by trying to make the dog vomit. Don’t try sticking your fingers down its throat, though. Instead, feed it a small dose (a teaspoon) of hydrogen peroxide or table salt. Your vet can handle things from there, and treatment usually involves giving the dog activated charcoal to bind to the toxins and using intravenous fluid therapy to flush them out.

Methylxanthines in chocolate are toxic for other animals, too. Cats are especially susceptible because of their small size. Luckily for them, cats lack the taste receptors that pick up “sweet” tastes, and rarely have much motivation for eating more than a nibble or two of chocolate. Both horses and humans are less susceptible to chocolate toxicity thanks to their size and faster metabolization of the chemicals. Methylxanthine poisoning can still happen to people who consume large amounts of chocolate or coffee in a small timeframe, though, and the amount of caffeine in a strong cup of coffee is enough to cause symptoms in a small child.

Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the Moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the Moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the Moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the Moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception—in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full Moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

This story was updated in 2019.

What's the Difference Between a Rabbit and a Hare?

iStock.com/Carmen Romero
iStock.com/Carmen Romero

Hippity, hoppity, Easter's on its way—and so is the eponymous Easter bunny. But aside from being a magical, candy-carrying creature, what exactly is Peter Cottontail: bunny, rabbit, or hare? Or are they all just synonyms for the same adorable animal?

In case you've been getting your fluffy, long-eared mammals mixed up, we've traveled down the rabbit hole to set the record straight. Although rabbits and hares belong to the same grass-munching family—called Leporidae—they're entirely different species with unique characteristics. It would be like comparing sheep and goats, geneticist Steven Lukefahr of Texas A&M University told National Geographic.

If you aren't sure which animal has been hopping around and helping themselves to the goodies in your vegetable garden, take a closer look at their ears. In general, hares have longer ears and larger bodies than rabbits. Rabbits also tend to be more social creatures, while hares prefer to keep to themselves.

As for the baby animals, they go by different names as well. Baby hares are called leverets, while newborn rabbits are called kittens or kits. So where exactly do bunnies fit into this narrative? Originally, the word bunny was used as a term of endearment for a young girl, but its meaning has evolved over time. Bunny is now a cutesy, childlike way to refer to both rabbits and hares—although it's more commonly associated with rabbits these days. With that said, the Easter bunny is usually depicted as a rabbit, but the tradition is thought to have originated with German immigrants who brought their legend of an egg-laying hare called "Osterhase" to America.

In other ambiguous animal news, the case of Bugs Bunny is a little more complicated. According to scientist and YouTuber Nick Uhas, the character's long ears, fast speed, and solitary nature seem to suggest he's a hare. However, in the cartoon, Bugs is shown burrowing underground, which doesn't jive with the fact that hares—unlike most rabbits—live aboveground. "We can draw the conclusion that Bugs may be a rabbit with hare-like behavior or a hare with rabbit nesting habits," Uhas says.

The conversation gets even more confusing when you throw jackrabbits into the mix, which aren't actually rabbits at all. Jackrabbits are various species of large hare that are native to western North America; the name itself is a shortened version of "jackass rabbit," which refers to the fact that the animal's ears look a little like a donkey's.

A jackrabbit
Connor Mah, Flickr // CC BY-SA 2.0

As Mark Twain once famously wrote about the creature, "He is just like any other rabbit, except that he is from one-third to twice as large, has longer legs in proportion to his size, and has the most preposterous ears that ever were mounted on any creature but the jackass." (Fun fact: Black-tailed jackrabbits' extra-long ears actually help them stay cool in the desert. The blood vessels in their ears enlarge when it gets hot, causing blood to flow to their ears and ridding their bodies of excess heat.)

Rabbits, hares, and jackrabbits all have one thing in common, though: They love a good salad. So if you happen across one of these hopping creatures, give them some grass or weeds—and skip the carrots. Bugs Bunny may have loved the orange vegetable, but most hares and rabbits would prefer leafy greens.

Have you got a Big Question you'd like us to answer? If so, send it to bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER