1 00:00:00,440 --> 00:00:04,040 Speaker 1: Hey, welcome to Science Stuff production of iHeartRadio. I'm Hora 2 00:00:04,240 --> 00:00:06,920 Speaker 1: Cham and today we are answering the question why can 3 00:00:07,080 --> 00:00:11,559 Speaker 1: dogs eat chocolate? Will a Hershey's kiss be the kiss 4 00:00:11,560 --> 00:00:14,280 Speaker 1: of death for your pooch? Or will a roller bar 5 00:00:14,520 --> 00:00:18,000 Speaker 1: make your dog roll over into the grave? How toxic 6 00:00:18,120 --> 00:00:21,000 Speaker 1: is chocolate to dogs? Why is it toxic? And when 7 00:00:21,000 --> 00:00:25,040 Speaker 1: do dogs evolve this intolerance. We'll talk to a couple 8 00:00:25,079 --> 00:00:29,400 Speaker 1: of veterinary toxicologists and to one dog geneticis to get 9 00:00:29,520 --> 00:00:32,920 Speaker 1: to the nougat center of this question. So come along 10 00:00:33,000 --> 00:00:36,879 Speaker 1: as we answer the question why can dogs eat chocolate? 11 00:00:37,600 --> 00:00:40,480 Speaker 1: I promise the answer won't be rough. 12 00:00:46,440 --> 00:00:46,640 Speaker 2: Hi. 13 00:00:46,680 --> 00:00:51,920 Speaker 1: Everyone, you've probably heard that eating chocolate is bad for dogs. People, 14 00:00:51,960 --> 00:00:55,560 Speaker 1: it seems, can eat a lot of chocolate and chocoholics, 15 00:00:55,720 --> 00:00:58,480 Speaker 1: I'm looking at you, but it seems to be dangerous 16 00:00:58,760 --> 00:01:03,480 Speaker 1: or even potentially deadly for dogs. Now, most people seem 17 00:01:03,520 --> 00:01:06,320 Speaker 1: to think that's because chocolate has a chemical in it 18 00:01:06,440 --> 00:01:09,640 Speaker 1: that is uniquely toxic for dogs, but that is perfectly 19 00:01:09,680 --> 00:01:13,319 Speaker 1: safe for humans. But as we'll learn today, that's not 20 00:01:13,480 --> 00:01:17,000 Speaker 1: really true. First, we'll talk about how serious it is 21 00:01:17,080 --> 00:01:19,800 Speaker 1: if a dog eats chocolate. Then we'll talk about what 22 00:01:19,920 --> 00:01:23,679 Speaker 1: chocolate does to dogs, and in the last segment, we'll 23 00:01:23,680 --> 00:01:27,600 Speaker 1: ask an evolutionary biologist to tell us when scientists think 24 00:01:27,800 --> 00:01:32,399 Speaker 1: this sensitivity evolved in dogs and spoiler alert, it may 25 00:01:32,440 --> 00:01:37,160 Speaker 1: be some humans's fault. Okay, the first topic is how 26 00:01:37,280 --> 00:01:40,640 Speaker 1: serious is it if a dog eats chocolate? So the 27 00:01:40,640 --> 00:01:44,200 Speaker 1: first thing I did was call an emergency hotline, not 28 00:01:44,319 --> 00:01:47,520 Speaker 1: because my dog had eaten chocolate, but to talk to 29 00:01:47,560 --> 00:01:50,400 Speaker 1: one of their experts. So here's my chat with doctor 30 00:01:50,600 --> 00:02:02,600 Speaker 1: Renee Schmidt. Thank you for calling Pet Poison Helpline, a 31 00:02:02,680 --> 00:02:05,280 Speaker 1: twenty four to seven animal poison control center. 32 00:02:05,760 --> 00:02:08,360 Speaker 3: If you are a pet owner, please press one. 33 00:02:10,880 --> 00:02:12,600 Speaker 2: Well, thank you doctor Schmidt for joining us. 34 00:02:13,160 --> 00:02:15,400 Speaker 4: Yeah, thank you so much for having me. I'm doctor 35 00:02:15,400 --> 00:02:18,400 Speaker 4: Rene Schmid with Pet Poison Helpline. I'm the director of 36 00:02:18,480 --> 00:02:24,480 Speaker 4: Veterinary Medicine and senior veterinary toxicologist, so I help educate 37 00:02:24,680 --> 00:02:28,880 Speaker 4: pet owners as well as venary professionals on anything toxin related, 38 00:02:28,960 --> 00:02:31,320 Speaker 4: as well as working with our staff internally. 39 00:02:31,760 --> 00:02:32,239 Speaker 2: Amazing. 40 00:02:32,360 --> 00:02:34,359 Speaker 1: Can you tell us about Pet Poison Hotline. 41 00:02:34,800 --> 00:02:37,680 Speaker 4: We are a twenty four to seven animal poison control 42 00:02:37,760 --> 00:02:41,680 Speaker 4: center and so pet parents as well as veterinary professionals 43 00:02:41,720 --> 00:02:45,320 Speaker 4: can call us, and if an animal has been exposed 44 00:02:45,360 --> 00:02:48,360 Speaker 4: to something that may be toxic, we can assess it 45 00:02:48,440 --> 00:02:50,840 Speaker 4: to determine if the exposure is going to be a 46 00:02:50,919 --> 00:02:54,120 Speaker 4: concern for that animal or not. While the vast majority 47 00:02:54,120 --> 00:02:56,400 Speaker 4: of calls we receive are end dogs and cats, so 48 00:02:56,600 --> 00:02:59,360 Speaker 4: we can help with any species of animal and with 49 00:02:59,480 --> 00:03:03,360 Speaker 4: anything that they get into. So we had a sloth 50 00:03:03,680 --> 00:03:07,200 Speaker 4: that's got into a cleaning chemical. We had a goose 51 00:03:07,280 --> 00:03:10,639 Speaker 4: not too long ago that got into marijuana. You name it, 52 00:03:10,840 --> 00:03:13,880 Speaker 4: and we've probably gotten a call on it. And we're 53 00:03:13,960 --> 00:03:15,440 Speaker 4: staff twenty four hours a day. 54 00:03:15,720 --> 00:03:18,160 Speaker 1: And you said you're all over the country, so we. 55 00:03:18,120 --> 00:03:20,679 Speaker 4: Take calls all over the country and really all over 56 00:03:20,720 --> 00:03:23,240 Speaker 4: the world. So the vast majority of our calls are 57 00:03:23,280 --> 00:03:26,480 Speaker 4: from the United States and Canada. We also take calls 58 00:03:26,520 --> 00:03:29,640 Speaker 4: from the Caribbean and Hong Kong and other countries throughout 59 00:03:29,680 --> 00:03:30,160 Speaker 4: the world. 60 00:03:30,639 --> 00:03:33,000 Speaker 1: Oh my goodness, And how do you cover twenty four hours? 61 00:03:33,040 --> 00:03:34,880 Speaker 1: Are you just constantly on calls. 62 00:03:35,160 --> 00:03:38,520 Speaker 4: Yeah, so we're a busy place. It's amazing how many 63 00:03:38,560 --> 00:03:41,440 Speaker 4: animals get into things that they couldn't. We have employees 64 00:03:41,480 --> 00:03:44,080 Speaker 4: who have ships throughout the day and evenings so that 65 00:03:44,160 --> 00:03:48,120 Speaker 4: we always have veterinarians and technicians who are on and 66 00:03:48,200 --> 00:03:49,920 Speaker 4: ready to take calls at any time. 67 00:03:50,400 --> 00:03:53,000 Speaker 1: How often do you get calls about dogs eating chocolate? 68 00:03:53,640 --> 00:03:56,320 Speaker 4: It's our number one call, It's our most common call. 69 00:03:56,600 --> 00:03:59,080 Speaker 4: I've been here for twelve years, we've been in business 70 00:03:59,160 --> 00:04:02,360 Speaker 4: for twenty one years, and it's been our number one 71 00:04:02,480 --> 00:04:05,400 Speaker 4: toxin every year since we've been keeping track. We always 72 00:04:05,480 --> 00:04:08,640 Speaker 4: look back the year prior to see what was our 73 00:04:08,880 --> 00:04:12,320 Speaker 4: top toxins, and chocolate always I always say it takes 74 00:04:12,360 --> 00:04:15,640 Speaker 4: the cake. It's always number one. You know, if you 75 00:04:15,680 --> 00:04:18,520 Speaker 4: think about it, so many households have chocolate in them. 76 00:04:18,880 --> 00:04:21,960 Speaker 4: Maybe we're cooking with it, we're buying it in different 77 00:04:22,000 --> 00:04:25,120 Speaker 4: products or candy and chocolate itself, or maybe it's in 78 00:04:25,160 --> 00:04:29,320 Speaker 4: brownies and cookies for the holidays, we're gifting it, and 79 00:04:29,360 --> 00:04:32,039 Speaker 4: so maybe it's under the tree, or it's sitting out 80 00:04:32,080 --> 00:04:35,520 Speaker 4: at parties and you know, activities and social events. So 81 00:04:36,000 --> 00:04:39,599 Speaker 4: it's something that is really a commonplace in so many 82 00:04:39,640 --> 00:04:44,360 Speaker 4: households that it smells good, it tastes good, so dogs 83 00:04:44,400 --> 00:04:46,600 Speaker 4: are naturally kind of drawn to it. 84 00:04:47,000 --> 00:04:48,600 Speaker 2: You say it takes the chocolate cake. 85 00:04:48,920 --> 00:04:51,240 Speaker 4: Yes, that's right, it takes the chocolate cake, for sure. 86 00:04:52,560 --> 00:04:55,200 Speaker 1: So, yeah, there are a lot of dogs out there 87 00:04:55,600 --> 00:05:00,640 Speaker 1: eating chocolate. Another animal poison control center would run by 88 00:05:00,640 --> 00:05:04,000 Speaker 1: the American Society for the Prevention of Cruelty to Animals 89 00:05:04,320 --> 00:05:09,040 Speaker 1: or ASBCA, reported that they receive about seventy six calls 90 00:05:09,040 --> 00:05:13,120 Speaker 1: a day of dogs eating chocolate, which translates to about 91 00:05:13,160 --> 00:05:18,520 Speaker 1: twenty seven thousand, seven hundred and forty cases a year. Next, 92 00:05:18,640 --> 00:05:22,000 Speaker 1: I ask sector SMIT, what happens if a dog eats chocolate? 93 00:05:23,360 --> 00:05:26,320 Speaker 1: What are some of the symptoms dogs might exhibit if 94 00:05:26,320 --> 00:05:27,080 Speaker 1: they eat it. 95 00:05:27,520 --> 00:05:32,160 Speaker 4: Yeah, so symptoms are similar to over simulation. So they 96 00:05:32,240 --> 00:05:36,000 Speaker 4: might be a little bit restless, they might be pacing, 97 00:05:36,400 --> 00:05:40,320 Speaker 4: panting that maybe agitate a little bit. They can have 98 00:05:40,360 --> 00:05:42,400 Speaker 4: a high heart rate, They can have a high blood 99 00:05:42,400 --> 00:05:45,919 Speaker 4: pressure depending on how much they ingest. They can have 100 00:05:46,960 --> 00:05:52,240 Speaker 4: heart abnormalities in rhythm abnormalities. Vomiting is certainly a common one, 101 00:05:52,279 --> 00:05:55,200 Speaker 4: as well as maybe some loose stool, and in some 102 00:05:55,360 --> 00:05:58,479 Speaker 4: cases it may not even be a toxic amount that 103 00:05:58,480 --> 00:06:02,039 Speaker 4: they get into. The can have a risk for pincreatitis, 104 00:06:02,160 --> 00:06:04,840 Speaker 4: which is just that inflammation of the pancreas when they 105 00:06:04,880 --> 00:06:08,560 Speaker 4: get a high fat meal, and because of the richness 106 00:06:08,560 --> 00:06:12,039 Speaker 4: of the chocolate, product itself, it could be enough to 107 00:06:12,120 --> 00:06:15,480 Speaker 4: cause that to flare up. So thinking about our dogs 108 00:06:15,520 --> 00:06:19,320 Speaker 4: that are more sensitive to pincreatitis, So the miniature Schnauzers 109 00:06:19,400 --> 00:06:23,159 Speaker 4: and Yorky's some of those breeds, that may be something 110 00:06:23,200 --> 00:06:25,520 Speaker 4: we have to be even more concerned about, even if 111 00:06:25,560 --> 00:06:28,640 Speaker 4: they didn't get into enough to cause a toxic concern. 112 00:06:29,160 --> 00:06:31,640 Speaker 1: Oh wait, it's also the fat content. 113 00:06:32,120 --> 00:06:34,680 Speaker 4: Yeah, sure can be. So it depends on the amount 114 00:06:34,680 --> 00:06:37,600 Speaker 4: that they get into. Dogs can tolerate a hershey kiss, 115 00:06:37,720 --> 00:06:40,560 Speaker 4: but who wants to stop it just one? And so 116 00:06:40,760 --> 00:06:43,040 Speaker 4: it's you know, when they get into that large handful 117 00:06:43,200 --> 00:06:46,240 Speaker 4: or the bag, that can definitely be more problematic and 118 00:06:46,320 --> 00:06:47,320 Speaker 4: cause that flare up. 119 00:06:47,480 --> 00:06:49,360 Speaker 1: Now would you see that immediately or is that more 120 00:06:49,400 --> 00:06:50,839 Speaker 1: of a long term concern. 121 00:06:51,240 --> 00:06:55,400 Speaker 4: So stomach sign so vomiting and diarrhea and loose stool, 122 00:06:55,480 --> 00:06:58,479 Speaker 4: that's something that we can see within a few hours, 123 00:06:58,920 --> 00:07:03,040 Speaker 4: the true and a development of pancreatitis might actually be 124 00:07:03,160 --> 00:07:06,800 Speaker 4: seen maybe later on twelve to twenty four hours or 125 00:07:06,839 --> 00:07:08,080 Speaker 4: even a day or so later. 126 00:07:10,520 --> 00:07:11,000 Speaker 2: That's right. 127 00:07:11,360 --> 00:07:14,640 Speaker 1: Eating chocolate can be serious for dogs. It can cause 128 00:07:14,680 --> 00:07:18,000 Speaker 1: heart problems, high blood pressure, it can affect the nervous 129 00:07:18,040 --> 00:07:22,200 Speaker 1: system and even cause seizures. According to the Cornell College 130 00:07:22,200 --> 00:07:25,559 Speaker 1: of Veterinary Medicine, drinking as little as half a cup 131 00:07:25,720 --> 00:07:29,760 Speaker 1: of chocolate milk can be deadly for an average chihuahua, 132 00:07:30,120 --> 00:07:33,080 Speaker 1: But according to doctor Schmid, not every call they get 133 00:07:33,360 --> 00:07:38,200 Speaker 1: is life threatening. You said it's your number one call. 134 00:07:38,640 --> 00:07:40,640 Speaker 1: I guess how would you break down those calls? Are 135 00:07:40,680 --> 00:07:43,440 Speaker 1: most of them pretty serious? Are some of them like, oh, 136 00:07:43,480 --> 00:07:46,040 Speaker 1: they ate a kiss or a small bar and they're 137 00:07:46,080 --> 00:07:47,920 Speaker 1: probably okay? How would you break that down? 138 00:07:48,320 --> 00:07:51,400 Speaker 4: That's a great question, And I would say that it's 139 00:07:51,760 --> 00:07:58,080 Speaker 4: really fairly evenly spread out to being not really an issue. Fortunately, 140 00:07:58,240 --> 00:08:02,280 Speaker 4: so many pet parents understand that chocolate is concerning to 141 00:08:02,400 --> 00:08:05,440 Speaker 4: their pet and they shouldn't get into it. So I 142 00:08:05,480 --> 00:08:09,679 Speaker 4: would say that it's a really pretty fairly evenly spread 143 00:08:09,800 --> 00:08:13,560 Speaker 4: between a mild or low concern. Maybe they just ingested 144 00:08:13,560 --> 00:08:16,880 Speaker 4: one chocolate chip cookie, and it's a labrador, it's a large, 145 00:08:16,920 --> 00:08:19,520 Speaker 4: free dog, and so probably not going to be a 146 00:08:19,520 --> 00:08:22,440 Speaker 4: big issue. But then we get this past Halloween, we 147 00:08:22,480 --> 00:08:24,760 Speaker 4: had a dog that ingested over six and a half 148 00:08:24,840 --> 00:08:27,920 Speaker 4: pounds of chocolate in one setting. 149 00:08:28,320 --> 00:08:30,960 Speaker 1: Oh my goodness, how did that dog get into six 150 00:08:31,000 --> 00:08:33,920 Speaker 1: pounds of chocolate? Was it they just had a chocolate factory, 151 00:08:34,000 --> 00:08:35,080 Speaker 1: or they had. 152 00:08:34,880 --> 00:08:38,640 Speaker 4: Their Halloween A family had their Halloween candy out because 153 00:08:38,679 --> 00:08:41,880 Speaker 4: it was Halloween Day or the day before, and it 154 00:08:42,000 --> 00:08:44,600 Speaker 4: was in an area that the dog was able to 155 00:08:44,679 --> 00:08:48,440 Speaker 4: get to and the owners weren't home at the time, 156 00:08:48,600 --> 00:08:50,319 Speaker 4: and he helped himself. 157 00:08:50,920 --> 00:08:53,280 Speaker 1: Well, it just opened up all the wrappers and everything. 158 00:08:53,400 --> 00:08:55,199 Speaker 4: He ingested a lot of the rappers. A lot of 159 00:08:55,200 --> 00:08:57,280 Speaker 4: the rappers were ingested and chewed him and kind of 160 00:08:57,280 --> 00:08:58,040 Speaker 4: broke them open. 161 00:08:58,120 --> 00:09:03,840 Speaker 1: And yeah, oh my goodness, yep, dogs love chocolate. Don't 162 00:09:03,880 --> 00:09:07,120 Speaker 1: even eat the wrappers, all right. This made me curious 163 00:09:07,240 --> 00:09:11,040 Speaker 1: if doctor Schmid ever gets calls about other animals getting 164 00:09:11,080 --> 00:09:15,800 Speaker 1: poisoned by chocolate. You mentioned other animals. Do you get 165 00:09:15,840 --> 00:09:18,959 Speaker 1: calls about other animals like cats? And what are some 166 00:09:19,200 --> 00:09:22,040 Speaker 1: unusual animals that you've had calls about chocolate? 167 00:09:22,160 --> 00:09:22,640 Speaker 2: So we do. 168 00:09:22,800 --> 00:09:26,360 Speaker 4: We get calls on every species, and the vast majority 169 00:09:26,400 --> 00:09:28,840 Speaker 4: of the calls we receive are going to be dogs 170 00:09:28,920 --> 00:09:32,760 Speaker 4: and then cats, And it makes sense because they're around 171 00:09:32,840 --> 00:09:36,160 Speaker 4: humans more. They just have more access to the things 172 00:09:36,200 --> 00:09:40,160 Speaker 4: in the household. We certainly get calls from chocolate on 173 00:09:40,320 --> 00:09:43,480 Speaker 4: other species of animals to you know, usually something like 174 00:09:43,520 --> 00:09:46,280 Speaker 4: a rabbit or a ferret, or maybe a chinchilla. 175 00:09:46,679 --> 00:09:49,320 Speaker 1: That's incredible. It's a little bit ironic that you would 176 00:09:49,320 --> 00:09:53,240 Speaker 1: have a bunny getting poison patrol call about chocolate. 177 00:09:53,559 --> 00:09:56,360 Speaker 4: Yeah right, Hopefully that rabbit didn't eat any of the 178 00:09:56,480 --> 00:09:57,640 Speaker 4: chocolate bunny at easter. 179 00:09:59,080 --> 00:10:03,480 Speaker 1: So chocolate effect other animals too, including cats and rabbits. 180 00:10:03,840 --> 00:10:06,960 Speaker 1: And if you search the scientific literature, you'll find reports 181 00:10:06,960 --> 00:10:11,880 Speaker 1: of chocolate poisoning in cows, bears, and even coyotes. So 182 00:10:12,160 --> 00:10:15,040 Speaker 1: what's going on here? What is it about chocolate that 183 00:10:15,120 --> 00:10:20,120 Speaker 1: makes it so harmful to so many animals except apparently humans. 184 00:10:20,520 --> 00:10:23,120 Speaker 1: When we come back, we'll talk to another expert on 185 00:10:23,200 --> 00:10:25,920 Speaker 1: what it means for something to be toxic and how 186 00:10:25,960 --> 00:10:28,240 Speaker 1: that affects what your pet can eat. 187 00:10:28,920 --> 00:10:41,560 Speaker 2: Stay with us, we'll be right back. Welcome back. Okay. 188 00:10:41,720 --> 00:10:44,720 Speaker 1: We learned that dogs definitely like chocolate, but that it's 189 00:10:44,760 --> 00:10:47,760 Speaker 1: not good for them. We also learned that it's not 190 00:10:47,800 --> 00:10:51,959 Speaker 1: good for other animals like cats and rabbits and even bears, 191 00:10:52,480 --> 00:10:55,640 Speaker 1: and yet people seem to be fine with it. In fact, 192 00:10:55,640 --> 00:10:59,520 Speaker 1: some of us eat it a lot. So what's going on? 193 00:11:00,160 --> 00:11:00,800 Speaker 2: To answer this? 194 00:11:00,960 --> 00:11:03,960 Speaker 1: I reached out to doctor Bob Poppingaate, a professor of 195 00:11:04,040 --> 00:11:08,000 Speaker 1: veterinary toxicology at the University of California at Davis who 196 00:11:08,080 --> 00:11:11,720 Speaker 1: runs the toxicology lab at the California Animal Health and 197 00:11:11,760 --> 00:11:15,160 Speaker 1: Food Safety Laboratory. He was just a few days from retiring, 198 00:11:15,240 --> 00:11:17,120 Speaker 1: but he took the time to talk to me. So 199 00:11:17,200 --> 00:11:21,600 Speaker 1: here's my conversation with doctor Bob Poppingate. Well, thank you 200 00:11:21,600 --> 00:11:23,040 Speaker 1: doctor popping Gate for joining us. 201 00:11:23,280 --> 00:11:24,199 Speaker 3: Pleasure to be here. 202 00:11:24,520 --> 00:11:26,839 Speaker 1: So today we're trying to answer the question of why 203 00:11:27,000 --> 00:11:30,360 Speaker 1: dogs can't eat chocolate, and I thought maybe we would 204 00:11:30,360 --> 00:11:34,200 Speaker 1: start by taking a step back, giving people a general 205 00:11:34,559 --> 00:11:38,040 Speaker 1: idea of what it means for something to be toxic 206 00:11:38,200 --> 00:11:39,640 Speaker 1: to an animal or to us. 207 00:11:40,080 --> 00:11:44,680 Speaker 3: Well, pretty much anything is toxic. Key is how much 208 00:11:44,760 --> 00:11:48,320 Speaker 3: is actually ingested. One of the tenants is that dose 209 00:11:48,440 --> 00:11:51,600 Speaker 3: makes the poison, So it's all about the inherent toxicity 210 00:11:51,640 --> 00:11:55,440 Speaker 3: of a compound, and also how much is actually ingested 211 00:11:55,440 --> 00:11:57,840 Speaker 3: by a dog or a person or a child, whatever. 212 00:11:58,200 --> 00:12:02,080 Speaker 3: Some things are more toxic inherently. If you ingest enough water, 213 00:12:02,200 --> 00:12:03,120 Speaker 3: that can be toxic. 214 00:12:04,480 --> 00:12:07,800 Speaker 1: Okay, According to doctor Popingay, there are two variables here, 215 00:12:08,240 --> 00:12:12,600 Speaker 1: how inherently toxic something is, In other words, how bad 216 00:12:12,640 --> 00:12:15,320 Speaker 1: it is for you and how much of it you eat. 217 00:12:16,000 --> 00:12:19,000 Speaker 1: For example, cyanide is bad for you even if you 218 00:12:19,040 --> 00:12:21,920 Speaker 1: only eat a little of it, But water, which is 219 00:12:22,040 --> 00:12:24,800 Speaker 1: normally good for you, can also be deadly if you 220 00:12:24,880 --> 00:12:28,320 Speaker 1: drink enough of it. Here's how doctor Popingay explains it. 221 00:12:29,320 --> 00:12:31,319 Speaker 1: What do you mean by everything can be toxic? 222 00:12:31,760 --> 00:12:35,520 Speaker 3: Well, it gets back to the inherent toxicity of a compound. So, 223 00:12:35,880 --> 00:12:38,520 Speaker 3: you know, there are certain vitamins that are required. We 224 00:12:38,760 --> 00:12:41,280 Speaker 3: ingest a certain amount of vitamin E or vitamin D 225 00:12:41,440 --> 00:12:45,480 Speaker 3: per day, but in excessive doses of vitamin E can 226 00:12:45,600 --> 00:12:49,559 Speaker 3: cause adverse effects. So it just depends on the individual compound. 227 00:12:49,679 --> 00:12:53,760 Speaker 3: But in sufficient doses, anything can be toxic to our bodies. 228 00:12:53,880 --> 00:12:56,800 Speaker 1: Now, what makes something more inherently toxic than others? 229 00:12:57,040 --> 00:12:59,320 Speaker 3: You know, it gets back to sort of the unique 230 00:12:59,440 --> 00:13:04,119 Speaker 3: characteristic of a compound and our ability to handle that compound. 231 00:13:04,400 --> 00:13:08,200 Speaker 1: These things do they generally interfere with how the body works. 232 00:13:08,280 --> 00:13:11,439 Speaker 1: Are these things burning a hole in my stomach or well. 233 00:13:11,280 --> 00:13:14,160 Speaker 3: There's a lot of different ways that a given chemical 234 00:13:14,240 --> 00:13:17,920 Speaker 3: can cause toxicity or adverse effects. You know, it can 235 00:13:17,960 --> 00:13:23,320 Speaker 3: affect our enzyme systems, it can affect neurotransmission, the neurotransmitters 236 00:13:23,320 --> 00:13:26,000 Speaker 3: that are released by our nervous system. It can block 237 00:13:26,120 --> 00:13:30,760 Speaker 3: certain body signals. It can damage cell membranes through what's 238 00:13:30,800 --> 00:13:34,520 Speaker 3: called oxidative damage, some things like corrosives. It's going to 239 00:13:34,600 --> 00:13:38,080 Speaker 3: cause damage to the mucosa, the upper gi track. So 240 00:13:38,240 --> 00:13:41,400 Speaker 3: a lot of different ways that chemicals can cause adverse effects. 241 00:13:41,600 --> 00:13:44,320 Speaker 1: Well, it seems that almost America, we can eat anything, 242 00:13:45,480 --> 00:13:48,520 Speaker 1: all right, So something can be toxic for lots of reasons. 243 00:13:48,840 --> 00:13:52,040 Speaker 1: There are almost endless ways in which chemicals can mess 244 00:13:52,040 --> 00:13:55,400 Speaker 1: with the signals in our bodies or directly damaged cells 245 00:13:55,640 --> 00:13:59,160 Speaker 1: or membranes. So now the question is what makes chocolate. 246 00:14:01,320 --> 00:14:05,120 Speaker 1: So then specifically for dogs, how bad is chocolate for dogs? 247 00:14:05,600 --> 00:14:09,040 Speaker 3: Well, that is very common intoxication in dogs. It's one 248 00:14:09,040 --> 00:14:11,440 Speaker 3: of the top things that veterians have to deal with. 249 00:14:11,640 --> 00:14:15,200 Speaker 3: But dogs can tolerate a certain amount of chocolate. The 250 00:14:15,480 --> 00:14:19,560 Speaker 3: chemicals in chocolate that cause problems, they're related and they're 251 00:14:19,560 --> 00:14:24,040 Speaker 3: called methyl xanthines. One is called theobromine, the other's caffeine. 252 00:14:24,080 --> 00:14:26,800 Speaker 3: So people are probably more familiar with caffeine, which is 253 00:14:26,840 --> 00:14:29,920 Speaker 3: also in chocolate, so we have both. People are less 254 00:14:29,920 --> 00:14:33,240 Speaker 3: familiar with the theobromine, which is related to caffeine has 255 00:14:33,280 --> 00:14:37,240 Speaker 3: the same effects, but the theobromine is at higher concentrations 256 00:14:37,280 --> 00:14:41,320 Speaker 3: in chocolate products. Those are the two compounds that cause problems. 257 00:14:42,920 --> 00:14:44,920 Speaker 1: Okay, this is kind of a key point. The ban 258 00:14:45,080 --> 00:14:50,000 Speaker 1: chemicals that make chocolate bad for dogs are caffeine and theobromine, 259 00:14:50,280 --> 00:14:54,040 Speaker 1: which is basically another form of caffeine. It's not some 260 00:14:54,160 --> 00:14:58,160 Speaker 1: exotic toxin or chemical. It's basically what we all drink 261 00:14:58,400 --> 00:15:01,880 Speaker 1: every day when we drink coffee or tea. Now does 262 00:15:01,880 --> 00:15:05,320 Speaker 1: caffeine or theobamine have some kind of special effect on 263 00:15:05,520 --> 00:15:10,880 Speaker 1: dogs that they don't have on us? Not really, Okay, 264 00:15:10,880 --> 00:15:12,800 Speaker 1: So then what do these compounds do to the dog. 265 00:15:12,880 --> 00:15:14,960 Speaker 1: Let's say a dog eats a bunch of the baking 266 00:15:15,000 --> 00:15:17,120 Speaker 1: chocolate or stip some coffee. 267 00:15:17,200 --> 00:15:18,480 Speaker 2: What is it going to do to their. 268 00:15:18,400 --> 00:15:23,360 Speaker 3: Body once it's absorbed. The theobromine caffeine effect the cardiovascular 269 00:15:23,400 --> 00:15:26,560 Speaker 3: system and the nervous system. So you know, if you 270 00:15:26,680 --> 00:15:29,040 Speaker 3: drink three or four cups of coffee in the morning, 271 00:15:29,280 --> 00:15:31,760 Speaker 3: you get a little bit nervous, your heart rate can 272 00:15:31,800 --> 00:15:35,400 Speaker 3: go up. These compounds are also diuretics, so you increase 273 00:15:35,440 --> 00:15:37,200 Speaker 3: your own production. That's why you have to go to 274 00:15:37,200 --> 00:15:39,880 Speaker 3: the bathroom after a few cups of coffee. But the 275 00:15:39,920 --> 00:15:43,800 Speaker 3: primary adverse effect is on the nervous system and our hearts. 276 00:15:44,080 --> 00:15:46,040 Speaker 3: So the heart rate goes up, you get a little 277 00:15:46,040 --> 00:15:49,479 Speaker 3: bit excited. With a really large dose, you could have seizures. 278 00:15:49,840 --> 00:15:53,080 Speaker 3: The most serious consequence is cardiac a arrhythmius, so your 279 00:15:53,240 --> 00:15:57,440 Speaker 3: heart rate changes. Of the dogs, the dogs are people 280 00:15:57,640 --> 00:16:00,400 Speaker 3: or any other species or animal that get into a 281 00:16:00,400 --> 00:16:01,640 Speaker 3: sufficient amount. 282 00:16:01,560 --> 00:16:04,560 Speaker 1: Like the same effect caffeine has in us it's having 283 00:16:04,600 --> 00:16:09,000 Speaker 1: on the dog. In other words, caffeine and theobromine have 284 00:16:09,080 --> 00:16:11,680 Speaker 1: the same effect on us as they do on dogs. 285 00:16:12,040 --> 00:16:15,000 Speaker 1: These chemicals are as toxic to them as they are 286 00:16:15,240 --> 00:16:18,400 Speaker 1: to us. But we drink coffee and eat chocolate all 287 00:16:18,400 --> 00:16:21,760 Speaker 1: the time. So how does that make sense. Well, the 288 00:16:21,840 --> 00:16:25,080 Speaker 1: answer is that while humans and dogs react to caffeine 289 00:16:25,080 --> 00:16:28,400 Speaker 1: and theobromine in the same way, there are differences that 290 00:16:28,440 --> 00:16:31,800 Speaker 1: affect our exposure to them. The first one is that 291 00:16:31,920 --> 00:16:34,360 Speaker 1: dogs are smaller than us. 292 00:16:35,800 --> 00:16:38,360 Speaker 3: Well, it gets back to how much the dog actually 293 00:16:38,560 --> 00:16:41,760 Speaker 3: ingest on a body weight basis, So we could be 294 00:16:41,800 --> 00:16:45,040 Speaker 3: intoxicated by these products as well if we ate enough 295 00:16:45,080 --> 00:16:48,480 Speaker 3: of them. These compounds can't be toxic to us, So 296 00:16:48,560 --> 00:16:51,760 Speaker 3: if a child got into baking chocolate and ingested half 297 00:16:51,760 --> 00:16:54,480 Speaker 3: a package, you might have a very sick child. 298 00:16:55,680 --> 00:16:59,000 Speaker 1: Yeah, so most dogs are smaller than us. For example, 299 00:16:59,040 --> 00:17:02,560 Speaker 1: a tiny shoe walla weighs about four pounds, so a 300 00:17:02,600 --> 00:17:05,760 Speaker 1: cup of chocolate milk to them would be the equivalent 301 00:17:05,840 --> 00:17:10,000 Speaker 1: of an average American eating ninety spoonfuls of cocoa powder 302 00:17:10,240 --> 00:17:13,800 Speaker 1: in one city. If you did that, you'd be pretty 303 00:17:13,800 --> 00:17:16,879 Speaker 1: sick too. The second difference that affects how much chocolate 304 00:17:17,000 --> 00:17:19,399 Speaker 1: dogs eat if the dogs don't seem to have a 305 00:17:19,400 --> 00:17:21,359 Speaker 1: lot of self control. 306 00:17:22,400 --> 00:17:25,120 Speaker 3: The other thing about dogs, why it's a problem. If 307 00:17:25,160 --> 00:17:27,520 Speaker 3: you have a dog, you know, they're very indiscriminate eaters. 308 00:17:27,840 --> 00:17:31,800 Speaker 3: They eat things and then ask questions later. If it's edible, 309 00:17:31,880 --> 00:17:33,879 Speaker 3: it's going to be very attractive for a dog. So 310 00:17:33,880 --> 00:17:36,160 Speaker 3: if they have access to a pan of brownies, they're 311 00:17:36,160 --> 00:17:38,359 Speaker 3: not going to stop with one brownie. You know, they're 312 00:17:38,359 --> 00:17:40,720 Speaker 3: going to clean up the entire pan of brownies. So 313 00:17:40,840 --> 00:17:44,040 Speaker 3: cats are about as sensitive to the chemicals and chocolate 314 00:17:44,119 --> 00:17:46,480 Speaker 3: as dogs are. But cats are not going to sit 315 00:17:46,520 --> 00:17:50,280 Speaker 3: there and eat a whole package of baking chocolate. Dogs 316 00:17:50,400 --> 00:17:53,080 Speaker 3: if they have access to something, they don't have any 317 00:17:53,080 --> 00:17:56,800 Speaker 3: self control, so they will eat everything there that's in 318 00:17:56,840 --> 00:18:00,639 Speaker 3: the package, whereas a person. You know, baking chocolate is 319 00:18:00,680 --> 00:18:03,400 Speaker 3: fairly bitter, so maybe a child might taste a little 320 00:18:03,440 --> 00:18:05,160 Speaker 3: bit of it, but they're not going to sit there 321 00:18:05,160 --> 00:18:06,680 Speaker 3: and eat the whole package. 322 00:18:06,800 --> 00:18:07,199 Speaker 2: I don't know. 323 00:18:08,080 --> 00:18:10,879 Speaker 1: I know there's some chocoholics who might dig into that 324 00:18:10,920 --> 00:18:16,200 Speaker 1: whole bag, right right, Okay. The last difference between people 325 00:18:16,280 --> 00:18:20,359 Speaker 1: and dogs is the dogs don't metabolize theobromine as well 326 00:18:20,600 --> 00:18:23,679 Speaker 1: as humans. Here's how doctor Schmid explains it. 327 00:18:25,040 --> 00:18:28,200 Speaker 4: Yeah, so in toxicology, we talked about a half life, 328 00:18:28,600 --> 00:18:32,199 Speaker 4: and the half life is the length of time it 329 00:18:32,320 --> 00:18:37,840 Speaker 4: takes the body to rid itself of half of the 330 00:18:37,960 --> 00:18:41,520 Speaker 4: amounts of that toxic component or what substance or drug 331 00:18:41,640 --> 00:18:44,960 Speaker 4: or what have you. And so the half life, the 332 00:18:45,040 --> 00:18:50,400 Speaker 4: amount of time it takes for dogs, in particular, to 333 00:18:50,560 --> 00:18:54,959 Speaker 4: rid the body of the theobromine, is much longer. In dogs, 334 00:18:55,000 --> 00:18:58,680 Speaker 4: it's about seventeen and a half hours, whereas in humans 335 00:18:58,720 --> 00:19:02,439 Speaker 4: it's just a few hours. And that definitely contributes to 336 00:19:03,000 --> 00:19:05,800 Speaker 4: the toxic effects that we see in dogs, and it 337 00:19:05,880 --> 00:19:09,600 Speaker 4: also contributes to the length of time that we see 338 00:19:09,680 --> 00:19:12,600 Speaker 4: or the duration of time that we see those effects. 339 00:19:14,440 --> 00:19:17,720 Speaker 1: So there is a difference between dog and human biology. 340 00:19:17,800 --> 00:19:20,720 Speaker 1: In terms of chocolate, the abromine and caffeine have the 341 00:19:20,800 --> 00:19:24,200 Speaker 1: same effect on us, but it takes longer for dogs 342 00:19:24,320 --> 00:19:28,480 Speaker 1: to break down those chemicals, so the effects last longer. Now, 343 00:19:28,560 --> 00:19:31,359 Speaker 1: most articles you read online will tell you this is 344 00:19:31,400 --> 00:19:35,000 Speaker 1: the main reason dogs can't eat chocolate, but actually both 345 00:19:35,040 --> 00:19:39,240 Speaker 1: experts agree that much bigger factors are a that dogs 346 00:19:39,240 --> 00:19:42,600 Speaker 1: are smaller and b that they can't stop themselves and 347 00:19:42,600 --> 00:19:46,000 Speaker 1: will eat huge amounts of chocolate if they have access 348 00:19:46,240 --> 00:19:49,639 Speaker 1: to it. Okay, the last question I asked doctor Poppingay 349 00:19:49,880 --> 00:19:55,720 Speaker 1: was now, why can't dogs metabolize these compounds as well 350 00:19:55,760 --> 00:19:57,080 Speaker 1: as humans? What's the difference? 351 00:19:57,320 --> 00:20:01,000 Speaker 3: They have different enzymes in their liver that break down compounds. 352 00:20:01,240 --> 00:20:03,960 Speaker 3: Every species says a little bit different. A good example 353 00:20:04,000 --> 00:20:07,080 Speaker 3: of a species difference is cats. You should never give 354 00:20:07,160 --> 00:20:09,760 Speaker 3: a set of metaphen or tilen all to a cat 355 00:20:09,880 --> 00:20:14,119 Speaker 3: because they can't metabolize the compound like we can or 356 00:20:14,200 --> 00:20:16,959 Speaker 3: dogs can. So cats are very sensitive to the adverse 357 00:20:16,960 --> 00:20:18,600 Speaker 3: effects of a set of menifin. 358 00:20:18,600 --> 00:20:19,920 Speaker 2: I see, so it's genetic. 359 00:20:20,160 --> 00:20:23,120 Speaker 3: It's genetic in the sense that it's a species difference. 360 00:20:23,560 --> 00:20:25,960 Speaker 1: Why do you think there are these differences in species. 361 00:20:26,320 --> 00:20:29,560 Speaker 3: Ah, that's a good question. That's kind of a evolutionary question, 362 00:20:29,840 --> 00:20:32,520 Speaker 3: and it probably goes back thousands, if not tens of 363 00:20:32,560 --> 00:20:33,600 Speaker 3: thousands of years. 364 00:20:35,440 --> 00:20:38,080 Speaker 1: Okay, when we come back, we'll actually try to answer 365 00:20:38,119 --> 00:20:41,560 Speaker 1: this question by going back in history with a dog 366 00:20:41,600 --> 00:20:47,200 Speaker 1: geneticis to where dogs came from. Don't go anywhere, we'll 367 00:20:47,240 --> 00:20:48,280 Speaker 1: be right back. 368 00:20:57,960 --> 00:20:59,840 Speaker 2: And we're back. Okay. 369 00:21:00,080 --> 00:21:03,160 Speaker 1: The last person I talked to was doctor Maya Arrand, 370 00:21:03,640 --> 00:21:07,320 Speaker 1: a professor at the University of Copenhagen. Here's what she does. 371 00:21:08,359 --> 00:21:11,600 Speaker 5: So my name is my aunt, and as well as 372 00:21:11,600 --> 00:21:13,880 Speaker 5: being a vet with a specialty and oncology, I'm also 373 00:21:14,200 --> 00:21:17,720 Speaker 5: a researcher in genetics and focus a lot on comparative genetics, 374 00:21:17,800 --> 00:21:20,320 Speaker 5: looking at genetics between humans and animals. And then I've 375 00:21:20,320 --> 00:21:23,399 Speaker 5: also worked a lot with dog evolutions, looking at bay 376 00:21:23,440 --> 00:21:26,680 Speaker 5: see how wolfs goot domesticated into dogs as we know 377 00:21:26,800 --> 00:21:27,160 Speaker 5: them today. 378 00:21:28,760 --> 00:21:31,280 Speaker 1: Now, the reason I talked to doctor Arrand is that 379 00:21:31,359 --> 00:21:35,320 Speaker 1: I wanted to know why dogs can't process chocolate as 380 00:21:35,400 --> 00:21:38,199 Speaker 1: well as people can. And it turned out that doctor 381 00:21:38,200 --> 00:21:42,240 Speaker 1: Aaron can paint a pretty interesting picture of why dogs 382 00:21:42,400 --> 00:21:45,879 Speaker 1: might have ended up that way and spoiler alert, it 383 00:21:45,960 --> 00:21:47,920 Speaker 1: might all be our fault. 384 00:21:48,119 --> 00:21:48,399 Speaker 2: Okay. 385 00:21:48,480 --> 00:21:51,000 Speaker 1: I started off by asking her to recap what we 386 00:21:51,119 --> 00:21:55,840 Speaker 1: know about where dogs come from. So can you give 387 00:21:55,920 --> 00:21:58,479 Speaker 1: us a brief history of dogs, like where did they 388 00:21:58,520 --> 00:21:59,000 Speaker 1: come from? 389 00:21:59,080 --> 00:22:02,640 Speaker 5: So dogs really originated from the gray wolf and they 390 00:22:02,640 --> 00:22:05,840 Speaker 5: were domesticated, well, actually, no one really knows exactly, but 391 00:22:06,000 --> 00:22:08,640 Speaker 5: as early as forty thousand years ago. Some say, oh, 392 00:22:08,680 --> 00:22:12,080 Speaker 5: it's definitely just one event that happened twenty three thousand 393 00:22:12,160 --> 00:22:15,720 Speaker 5: years ago in Siberia, but there's also suggestions that dog 394 00:22:15,800 --> 00:22:20,280 Speaker 5: domestication has been happening several places around the world. Somewhere 395 00:22:20,320 --> 00:22:22,359 Speaker 5: along the time, there's been some wolves that were maybe 396 00:22:22,720 --> 00:22:26,240 Speaker 5: less fearful of humans and have sort of been more curious, 397 00:22:26,440 --> 00:22:28,240 Speaker 5: and those are the ones that have sort of been 398 00:22:28,640 --> 00:22:31,199 Speaker 5: closer around humans. There's also a theory that they have 399 00:22:31,320 --> 00:22:35,200 Speaker 5: maybe been interested in scavenging, so scavenging around the places 400 00:22:35,200 --> 00:22:38,560 Speaker 5: where humans have lived, and these factors sort of led 401 00:22:38,600 --> 00:22:42,320 Speaker 5: to humans and wolves being in closer proximity. And then 402 00:22:42,400 --> 00:22:45,639 Speaker 5: the exact sort of domestication, if it's been humans taking 403 00:22:45,680 --> 00:22:49,840 Speaker 5: wolf puppies because they look cute or how this happened 404 00:22:49,920 --> 00:22:51,400 Speaker 5: is not exactly sure. 405 00:22:51,720 --> 00:22:55,720 Speaker 1: Interesting so at some point. The first dogs were just 406 00:22:55,800 --> 00:22:58,760 Speaker 1: domesticated wolves, and so they look like wolves, but now 407 00:22:58,760 --> 00:23:01,160 Speaker 1: they look like Chihuaha's and poodles. 408 00:23:01,280 --> 00:23:03,760 Speaker 5: Yeah, so there has been a lot of heavy selection 409 00:23:03,880 --> 00:23:07,080 Speaker 5: towards the dogs that we known in today, and yes, 410 00:23:07,200 --> 00:23:10,560 Speaker 5: originally the dogs that existed many thousand years ago, they 411 00:23:10,680 --> 00:23:13,720 Speaker 5: have looked or resembled much more the gray wolf as 412 00:23:13,720 --> 00:23:16,640 Speaker 5: we know it today. But what really happened is, obviously 413 00:23:16,800 --> 00:23:20,800 Speaker 5: people have selected for dogs to be used for different purposes. 414 00:23:21,000 --> 00:23:24,000 Speaker 5: They have chosen dogs that fitted to a certain purpose 415 00:23:24,160 --> 00:23:25,479 Speaker 5: and tried to breathe these together. 416 00:23:26,680 --> 00:23:30,000 Speaker 1: Okay, so only up to about twenty to forty thousand 417 00:23:30,080 --> 00:23:33,960 Speaker 1: years ago, there were no dogs. There were just wolves. 418 00:23:34,400 --> 00:23:37,080 Speaker 1: And then one or two kinds of wolves started hanging 419 00:23:37,119 --> 00:23:41,720 Speaker 1: around people and a best friendship was born. So every 420 00:23:41,840 --> 00:23:45,360 Speaker 1: dog today signed this belief came from those first wolves 421 00:23:45,440 --> 00:23:48,679 Speaker 1: that were friendly to humans. So how do you go 422 00:23:48,760 --> 00:23:55,080 Speaker 1: from a huge, fierce looking gray wolf to poodles in chiwalas? 423 00:23:57,720 --> 00:24:00,479 Speaker 5: Significantly? I think around two hundred years ago, aways sort 424 00:24:00,520 --> 00:24:03,520 Speaker 5: of the first kennel clubs we're established, and their people say, 425 00:24:03,640 --> 00:24:06,160 Speaker 5: now we're going to create these different breeds of dogs, 426 00:24:06,200 --> 00:24:08,520 Speaker 5: and we have to have pedigrees so we can sort 427 00:24:08,520 --> 00:24:11,240 Speaker 5: of be sure that we're only breeding dogs from the 428 00:24:11,280 --> 00:24:14,560 Speaker 5: same breed, and there we've sort of selected very stringently 429 00:24:14,600 --> 00:24:17,040 Speaker 5: towards the breeds that we have today. This has had 430 00:24:17,080 --> 00:24:19,480 Speaker 5: some consequences, and it doesn't mean that there is a 431 00:24:19,520 --> 00:24:22,600 Speaker 5: lot of inbreeding within certain dog breeds. And there's also 432 00:24:22,640 --> 00:24:25,920 Speaker 5: been some sort of negative health consequences that we don't 433 00:24:25,960 --> 00:24:29,000 Speaker 5: really see in their ancestors, as in the gray wolf. 434 00:24:29,400 --> 00:24:33,040 Speaker 1: Oh so the big diversification that we've seen dogs today 435 00:24:33,359 --> 00:24:36,359 Speaker 1: only maybe mostly happen in the last few hundred years. 436 00:24:36,600 --> 00:24:39,680 Speaker 5: I mean, if you look at sort of old paintings, 437 00:24:39,800 --> 00:24:43,600 Speaker 5: you can definitely see there's sort of different dog phenotypes. 438 00:24:43,640 --> 00:24:46,560 Speaker 5: But now we have these really different breeds. That's really 439 00:24:46,560 --> 00:24:49,520 Speaker 5: something that's only happened very recently. And what happens every 440 00:24:49,520 --> 00:24:52,040 Speaker 5: time you sort of do this selection is you create 441 00:24:52,080 --> 00:24:54,760 Speaker 5: what we call a genetic bottleneck, is where you have 442 00:24:54,920 --> 00:24:57,840 Speaker 5: only a small amount of genetic material that goes further 443 00:24:57,880 --> 00:25:00,240 Speaker 5: to great and new population. And this does I mean 444 00:25:00,320 --> 00:25:03,399 Speaker 5: that you will have a lot of sort of inbreeding 445 00:25:03,600 --> 00:25:05,600 Speaker 5: within different dog breeds. 446 00:25:05,720 --> 00:25:08,440 Speaker 1: What you're saying makes me wonder if one of those 447 00:25:08,440 --> 00:25:12,000 Speaker 1: negative consequences could have been an intolerance for chocolate. 448 00:25:12,119 --> 00:25:15,400 Speaker 5: So that's a really interesting question why dogs don't tolerate 449 00:25:15,560 --> 00:25:16,320 Speaker 5: chocolate very. 450 00:25:16,160 --> 00:25:21,080 Speaker 1: Well, Okay, this is where it gets interesting. Doctor arend 451 00:25:21,119 --> 00:25:24,040 Speaker 1: has been a part of several teams that have sequenced 452 00:25:24,040 --> 00:25:27,760 Speaker 1: the dog genome. That means they catalog the genes in 453 00:25:27,880 --> 00:25:30,880 Speaker 1: dog DNA, and there are two studies that tell an 454 00:25:30,960 --> 00:25:36,600 Speaker 1: interesting story about dogs and potentially chocolate. In the first study, 455 00:25:36,880 --> 00:25:40,840 Speaker 1: doctor Aren't and other researchers compared the DNA of dogs 456 00:25:41,040 --> 00:25:44,399 Speaker 1: to the DNA of wolves. Here's how she describes it. 457 00:25:46,080 --> 00:25:48,720 Speaker 5: Yeah, so that's really my favorite part of my research 458 00:25:48,800 --> 00:25:51,159 Speaker 5: because it was such a clear signal we saw some 459 00:25:51,280 --> 00:25:54,320 Speaker 5: years ago. We decided to look at the differences between 460 00:25:54,320 --> 00:25:57,159 Speaker 5: wolves and dogs. So basically, sequence the pool of different 461 00:25:57,200 --> 00:25:59,960 Speaker 5: wolves from different parts of the world, and then sequence 462 00:26:00,400 --> 00:26:04,040 Speaker 5: of different dog breeds and then try to look at differences. 463 00:26:04,240 --> 00:26:06,919 Speaker 5: And what we could see is, obviously we found a 464 00:26:06,920 --> 00:26:09,840 Speaker 5: lot of signals that were related to newer developments. So 465 00:26:10,280 --> 00:26:14,359 Speaker 5: this suggests that obviously there's difference in behavior and how 466 00:26:14,400 --> 00:26:16,520 Speaker 5: the brain functions between wolves and dogs. 467 00:26:17,640 --> 00:26:20,280 Speaker 1: All Right, the first difference they saw between dog and 468 00:26:20,359 --> 00:26:24,639 Speaker 1: wolf DNA was in genes related to their brains, and 469 00:26:24,680 --> 00:26:27,400 Speaker 1: this makes sense because we know that one big difference 470 00:26:27,440 --> 00:26:32,000 Speaker 1: between dogs and wolves is that they behave differently. Wolves 471 00:26:32,040 --> 00:26:36,639 Speaker 1: are wild and dogs are domesticated. But then they saw 472 00:26:36,680 --> 00:26:38,520 Speaker 1: another clear difference. 473 00:26:40,119 --> 00:26:42,800 Speaker 5: But one of the sort of really strikingly clear signals 474 00:26:42,800 --> 00:26:46,280 Speaker 5: we also saw was related to the digestion of starch. 475 00:26:46,880 --> 00:26:50,000 Speaker 5: We know that wolves are really cardivores, so they tend 476 00:26:50,000 --> 00:26:53,159 Speaker 5: to eat meat only. So there are hunters in the 477 00:26:53,160 --> 00:26:56,480 Speaker 5: wildlife and they will mostly eat and hunt different types 478 00:26:56,520 --> 00:26:59,679 Speaker 5: of prey. And we look at dogs, it seems like 479 00:26:59,760 --> 00:27:02,480 Speaker 5: they are sort of closer to on their wards, so 480 00:27:02,520 --> 00:27:05,679 Speaker 5: they can also tolerate other substances, or they can also 481 00:27:05,840 --> 00:27:08,320 Speaker 5: sort of feed on starch containing foods. 482 00:27:09,400 --> 00:27:12,280 Speaker 1: Okay, what they saw was that the genes of dogs 483 00:27:12,359 --> 00:27:16,440 Speaker 1: were also more adapted to eat starches, meaning that when 484 00:27:16,440 --> 00:27:19,560 Speaker 1: they were wolves they only ate meat, but once they 485 00:27:19,560 --> 00:27:23,480 Speaker 1: became dogs, their digestive system changed so they could eat 486 00:27:23,520 --> 00:27:28,120 Speaker 1: basically carbs like rice and wheat. What does this mean? 487 00:27:29,760 --> 00:27:31,919 Speaker 5: So what we could see in our research was we 488 00:27:32,000 --> 00:27:36,119 Speaker 5: really found relatively strong signals that suggested that dogs have 489 00:27:36,400 --> 00:27:40,120 Speaker 5: not only been domesticated sort of in relation to their 490 00:27:40,119 --> 00:27:43,080 Speaker 5: behavior to living humans, but actually they also seem to 491 00:27:43,160 --> 00:27:45,280 Speaker 5: have adapted to the diet that we eat. 492 00:27:45,880 --> 00:27:49,119 Speaker 1: Does that mean that dogs can digest sugars more? 493 00:27:49,440 --> 00:27:51,760 Speaker 5: Yes, that's definitely our theory. 494 00:27:52,800 --> 00:27:56,000 Speaker 1: What doctor rn is saying is that as dogs became 495 00:27:56,240 --> 00:27:59,959 Speaker 1: dogs and started living with humans, they adapted to our 496 00:28:00,080 --> 00:28:03,520 Speaker 1: or diet, and that meant being more omnivorous and being 497 00:28:03,600 --> 00:28:08,360 Speaker 1: able to eat a wider range of foods, including perhaps chocolate. 498 00:28:09,560 --> 00:28:13,000 Speaker 1: I wonder if this adaptation being able to eat more 499 00:28:13,080 --> 00:28:16,800 Speaker 1: sugars has made them more prone to eating the chocolate 500 00:28:16,840 --> 00:28:19,840 Speaker 1: we leave around, Meaning like, if I leave a chunk 501 00:28:19,840 --> 00:28:22,399 Speaker 1: of chocolate with a wolf, would the wolf want to 502 00:28:22,400 --> 00:28:24,879 Speaker 1: eat this? Maybe not because it wouldn't taste good or 503 00:28:24,880 --> 00:28:26,280 Speaker 1: wouldn't have that drive to eat it. 504 00:28:26,359 --> 00:28:26,960 Speaker 2: What do you think? 505 00:28:27,160 --> 00:28:29,239 Speaker 5: So that is a really good question. One of the 506 00:28:29,280 --> 00:28:31,359 Speaker 5: things we did see in our data originally was some 507 00:28:31,400 --> 00:28:34,520 Speaker 5: of the taste receptors in the tongues, and there potentially 508 00:28:34,560 --> 00:28:37,600 Speaker 5: could be some differences there, But it's definitely something that 509 00:28:37,960 --> 00:28:41,000 Speaker 5: would make sense that as part of this adaptation, that 510 00:28:41,040 --> 00:28:44,160 Speaker 5: maybels actually think that this chocolate didn't taste good and 511 00:28:44,280 --> 00:28:47,840 Speaker 5: dogs would be more sort of interested in it. But again, 512 00:28:47,880 --> 00:28:50,200 Speaker 5: that would be a very theoretical question. I don't think 513 00:28:50,200 --> 00:28:52,160 Speaker 5: anyone's sort of shown that. 514 00:28:53,440 --> 00:28:53,760 Speaker 2: Okay. 515 00:28:53,880 --> 00:28:56,760 Speaker 1: The second interesting thing doctor arn has found when looking 516 00:28:56,800 --> 00:29:00,280 Speaker 1: at the DNA of dogs is that actually dogs do 517 00:29:00,400 --> 00:29:05,320 Speaker 1: have a gene that can help them metabolize chocolate or theobromine. 518 00:29:06,000 --> 00:29:09,160 Speaker 5: One of the interesting things we saw in our new 519 00:29:09,200 --> 00:29:12,840 Speaker 5: reference genome was we found a duplication, So that means 520 00:29:12,880 --> 00:29:14,800 Speaker 5: that instead of just having one copy of a gene, 521 00:29:14,840 --> 00:29:17,600 Speaker 5: you can have multiple of a gene called SIP one 522 00:29:17,640 --> 00:29:21,280 Speaker 5: A two, and that is a gene that encodes enzyme 523 00:29:21,360 --> 00:29:25,960 Speaker 5: that's important for digesting what called cenobiotics, for instance, theobromine 524 00:29:26,400 --> 00:29:29,600 Speaker 5: that the body doesn't produce itself. And we can see 525 00:29:29,760 --> 00:29:32,520 Speaker 5: that based on the twenty seven other dogs we had 526 00:29:32,560 --> 00:29:35,840 Speaker 5: in our data set, that some dogs have two copies 527 00:29:35,880 --> 00:29:38,240 Speaker 5: of the SIP one A two and then some dogs 528 00:29:38,280 --> 00:29:39,800 Speaker 5: would have up to five copies. 529 00:29:40,960 --> 00:29:44,400 Speaker 1: So dogs have multiple copies up to five of a 530 00:29:44,520 --> 00:29:47,680 Speaker 1: gene that would produce an enzyme that would help them 531 00:29:47,800 --> 00:29:51,680 Speaker 1: break down theobromine, the chemical in chocolate. They can make 532 00:29:51,720 --> 00:29:55,840 Speaker 1: them sick, but for some reason the gene doesn't get used. 533 00:29:57,360 --> 00:30:03,080 Speaker 5: Specifically, it's SIP one two that's been associated with theobromine digestion. 534 00:30:03,120 --> 00:30:05,600 Speaker 5: And then there's actually also one that's called sip to 535 00:30:06,240 --> 00:30:10,280 Speaker 5: E one I believe, which also been linked to theobromin digestion. 536 00:30:10,360 --> 00:30:12,800 Speaker 5: And the dogs have both of these genes, so it's 537 00:30:12,840 --> 00:30:15,280 Speaker 5: not like they're missing one or it doesn't exist. And 538 00:30:15,320 --> 00:30:18,320 Speaker 5: that's why, Well, if they have the genes that required, 539 00:30:18,400 --> 00:30:21,320 Speaker 5: why do we eat then see that they get this 540 00:30:21,480 --> 00:30:24,000 Speaker 5: chocolate toxicos is more frequently than you would see, you know, 541 00:30:24,040 --> 00:30:26,840 Speaker 5: the species, And that's maybe down to the way the 542 00:30:26,880 --> 00:30:29,360 Speaker 5: genes are expressed, so that maybe just not expressed in 543 00:30:29,400 --> 00:30:30,400 Speaker 5: a high enough amount. 544 00:30:31,600 --> 00:30:34,760 Speaker 1: So they have the gene to process theobromaine. We just 545 00:30:34,800 --> 00:30:37,920 Speaker 1: don't know why they don't express it enough to help them. 546 00:30:38,080 --> 00:30:40,200 Speaker 5: Yeah, I guess that would be the theory that they're 547 00:30:40,240 --> 00:30:43,120 Speaker 5: not expressing it high enough or fast enough as they 548 00:30:43,160 --> 00:30:44,760 Speaker 5: are in humans. 549 00:30:46,200 --> 00:30:49,640 Speaker 1: Doctor arn says that a possible theory is that dogs 550 00:30:49,760 --> 00:30:52,560 Speaker 1: have the genes to break down the chemicals and chocolate, 551 00:30:52,880 --> 00:30:56,120 Speaker 1: but maybe changes in other parts of the DNA are 552 00:30:56,160 --> 00:30:59,800 Speaker 1: preventing these genes from expressing themselves to actually make the 553 00:31:00,320 --> 00:31:04,440 Speaker 1: enzymes to digest chocolate. One potential source of these changes 554 00:31:04,680 --> 00:31:08,440 Speaker 1: could be the interbreeding that's happened in dogs over the 555 00:31:08,520 --> 00:31:10,520 Speaker 1: last few hundred years. 556 00:31:12,000 --> 00:31:14,440 Speaker 5: So there have been people showing that there have been 557 00:31:14,480 --> 00:31:17,160 Speaker 5: two sort of small genetic variants in the SIT one 558 00:31:17,200 --> 00:31:19,920 Speaker 5: agen that we can see that occurrent dogs, and they 559 00:31:20,000 --> 00:31:24,720 Speaker 5: have hypothesized that these genegrants made the one A two 560 00:31:25,080 --> 00:31:28,640 Speaker 5: gene function worse, so when it was translated into enzyme, 561 00:31:28,880 --> 00:31:32,000 Speaker 5: that enzyme wasn't as good as digesting deobromine. 562 00:31:32,320 --> 00:31:35,200 Speaker 1: So it seems like maybe a possible picture. We can't 563 00:31:35,200 --> 00:31:37,760 Speaker 1: say anything for certain, but a possible picture is that 564 00:31:37,920 --> 00:31:41,400 Speaker 1: dogs adapted to human diet, but something happened along the 565 00:31:41,400 --> 00:31:46,360 Speaker 1: way that made them not adapt to theobromaine digestion, which 566 00:31:46,440 --> 00:31:48,520 Speaker 1: kind of puts them in this bad spot where they're 567 00:31:48,880 --> 00:31:51,400 Speaker 1: adapted to eating our food, but just not this one 568 00:31:51,440 --> 00:31:55,080 Speaker 1: particular food. And so that's why it's such a problem today. 569 00:31:55,480 --> 00:31:58,280 Speaker 5: Yeah, I think probably that is pretty correctly. 570 00:31:57,960 --> 00:32:02,440 Speaker 1: Put In other words, it's because of us that dogs 571 00:32:02,560 --> 00:32:06,120 Speaker 1: can and want to eat foods like chocolate, but along 572 00:32:06,160 --> 00:32:09,040 Speaker 1: the way they might have lost been able to digest 573 00:32:09,120 --> 00:32:12,760 Speaker 1: the chemicals and chocolate maybe also because of us and 574 00:32:12,800 --> 00:32:16,920 Speaker 1: all the interbreeding we've done to them. So maybe the 575 00:32:16,960 --> 00:32:19,120 Speaker 1: problem is we need to give more chocolate to dogs. 576 00:32:20,200 --> 00:32:23,400 Speaker 5: Yes, tell us, I said evolution doesn't happen over time, 577 00:32:23,480 --> 00:32:26,240 Speaker 5: and for that selection to happen, there will be a 578 00:32:26,240 --> 00:32:29,200 Speaker 5: lot of dogs that would not do well. Yeah, so 579 00:32:29,480 --> 00:32:32,000 Speaker 5: I think the better idea is probably not to give 580 00:32:32,040 --> 00:32:32,760 Speaker 5: dogs chocolate. 581 00:32:33,840 --> 00:32:36,880 Speaker 1: Yeah, we'd better for humans just to stop eating chocolate, 582 00:32:37,200 --> 00:32:38,360 Speaker 1: or at least humans with dogs. 583 00:32:38,480 --> 00:32:40,840 Speaker 5: Well yeah, I'm not sure if humans should completely stop 584 00:32:40,840 --> 00:32:44,480 Speaker 5: eating chocolate, but they should be more careful lenient around 585 00:32:44,520 --> 00:32:46,560 Speaker 5: where dogs can get access to it. 586 00:32:46,760 --> 00:32:50,480 Speaker 2: That makes total sense, all right. 587 00:32:50,560 --> 00:32:54,160 Speaker 1: To recap, the answer to the question why can't dogs 588 00:32:54,200 --> 00:32:58,120 Speaker 1: eat chocolate seems to be mainly the dogs are smaller 589 00:32:58,160 --> 00:33:01,800 Speaker 1: than us, and they are which makes it easier for 590 00:33:01,880 --> 00:33:05,920 Speaker 1: them to overdose on the caffeine, the bromine and fad 591 00:33:06,320 --> 00:33:09,440 Speaker 1: in chocolate. And on top of that, they've lost the 592 00:33:09,440 --> 00:33:13,520 Speaker 1: ability to quickly break down some of these chemicals, maybe 593 00:33:13,640 --> 00:33:17,160 Speaker 1: because of us. So if you own a dog, be 594 00:33:17,240 --> 00:33:20,520 Speaker 1: sure to put away or eat all your spared chocolate. 595 00:33:21,080 --> 00:33:23,120 Speaker 2: And that's just dogon good advice. 596 00:33:23,680 --> 00:33:29,400 Speaker 1: Thanks for joining us, See you next time you've been 597 00:33:29,440 --> 00:33:33,360 Speaker 1: listening to science stuff. The production of iHeartRadio written and 598 00:33:33,360 --> 00:33:36,800 Speaker 1: produced by me or Hey Cham, edited by Rose Seguda, 599 00:33:37,240 --> 00:33:40,600 Speaker 1: Executive producer Jerry Rowland, and audio engineer and mixer Ksey 600 00:33:40,640 --> 00:33:43,400 Speaker 1: Pegram and you can follow me on social media. 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