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.

Full vs. Queen Mattress: What's the Difference?

iStock.com/IPGGutenbergUKLtd
iStock.com/IPGGutenbergUKLtd

If you’re in the market for a new mattress this Presidents Day weekend (the holiday is traditionally a big one for mattress retailers), one of the first decisions you’ll need to make is regarding size. Most people know a king mattress offers the most real estate, but the difference between a full-sized mattress and a queen-sized one provokes more curiosity. Is it strictly a matter of width, or are depth and length factors? Is there a recommended amount of space for each slumbering occupant?

Fortunately, mattress manufacturers have made things easier by adhering to a common set of dimensions, which are sized as follows:

Crib: 27 inches wide by 52 inches long

Twin: 38 inches wide by 75 inches long

Full: 53 inches wide by 75 inches long

Queen: 60 inches wide by 80 inches long

King: 76 inches wide by 80 inches long

Depth can vary across styles. And while you can find some outliers—there’s a twin XL, which adds 5 inches to the length of a standard twin, or a California king, which subtracts 4 inches from the width and adds it to the length—the four adult sizes listed above are typically the most common, with the queen being the most popular. It's 7 inches wider than a full (sometimes called a “double”) mattress and 5 inches longer.

In the 1940s, consumers didn’t have as many options. Most people bought either a twin or full mattress. But in the 1950s, a post-war economy boost and a growing average height for Americans contributed to an increasing demand for larger bedding.

Still, outsized beds were a novelty and took some time to fully catch on. Today, bigger is usually better. If your bed is intended for a co-sleeping arrangement with a partner, chances are you’ll be looking at a queen. A full mattress leaves each occupant only 26.5 inches of width, which is actually slightly narrower than a crib mattress intended for babies and toddlers. A queen offers 30 inches, which is more generous but still well below the space provided by a person sleeping alone in a twin or full. For maximum couple comfort, you might want to consider a king, which is essentially like two twin beds being pushed together.

Your preference could be limited by the size of your bedroom—you might not be able to fit a nightstand on each side of a wider bed, for example—and whether you’ll have an issue getting a larger mattress up stairs and/or around tricky corners. Your purchase will also come down to a laundry list of options like material and firmness, but knowing which size you want helps narrow down your choices.

One lingering mystery remains: Why do we tend to shop for mattresses on Presidents Day weekend? One reason could be time. The three-day weekend is one of the first extended breaks since the December holidays, giving people an opportunity to trial different mattress types and deliberate with a partner. Shopping Saturday and Sunday allows people to sleep on it before making a decision.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

Do Mission Control Personnel Go Through as Many Simulations as Astronauts?

David McNew, Getty Images
David McNew, Getty Images

Jared Olson:

Mission control personnel go through a lot more simulations than astronauts, as the flight controller needs to develop very specialized skills and knowledge. On the other hand, astronauts in general need to develop the appropriate depth of knowledge across many disciplines. So shorter classes targeted to their needs are used instead to make the best use of their limited time.

I was the robotics instructor for the EVA simulation (or sim) yesterday and the rig (the simulator system) was not behaving for me. Things were up and running quickly, but after I simulated the main robotics computer having a fatal software fault things went downhill. The team rebooted it to recover, as expected, but the rig did not cleanly handle the reboot.

Suddenly it would not accept any commands to the robot arm. The hand controllers were not communicating. And the astronauts' laptop would not connect.

Eventually, I ran out of troubleshooting options and had to tell my three robotics flight controllers in training that all this was unplanned and the sim was not going to go as expected for them. Other disciplines had "scripting priority," as there were controllers who were assigned to use this sim as an evaluation toward their certifications. I did not have the leverage to disrupt the sim by halting the rig to reset the robotics simulator.

Flight controllers go through so many sims partly because of days like this—where, for whatever reason, they don't get as much "content" as we'd like. I told my guys to greencard that the arm simulator was working as expected, which means that they had to pretend they were seeing all the telemetry indications that would normally happen for the arm supporting an EVA. Basically: Just follow along and pretend.

Each simulation is unique in terms of the coordination required with other disciplines, the malfunctions they get to work through, and the timing involved in planning. Throughout their training flow they need to display their ability to work through a broad enough variety of cases before we can call them "certified." How much they get out of each sim can be a roll of the dice.

This post originally appeared on Quora. Click here to view.

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