Human Foods That Are Poisonous to Other Animals…

I sometimes watch strategy games online, and XCOM: Chimera Squad was one of those games. One of the characters in the games is Verge, a Sectoid, or those old B-movie aliens with big heads and ovaloid eyes. What piqued my interest was that in one of the conversations in the game between different playable characters, Verge was discussing how Sectoids cannot eat human processed food because it is poisonous to them. However, the one food that is edible to Sectoids is butter, or as Verge said - and I am paraphrasing it - “it is weird to eat a food made from another lactating mammal”. I know that humans obviously cannot eat everything that other animals feed on for a living, but is the food that humans eat - regardless of whether or not it is processed - digestible by all animals?

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I will reverse: I do not think that there is much food which humans cannot eat and animals can. Citing Good Soldier Schweik: humans are not pigs, humans will eat everything.

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Depends on type of food, groups like gulls with high acid level in stomachs will digest anything, is it healthy for them? Mostly no. Plus as a note even humans can’t digest all food they’re eating, all fungi and big part of plant material can’t be totally digested.

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Onions, grapes (especially raisins), chocolate, and garlic are all toxic to domestic dogs. I would be curious if their wild relatives have the same sensitivities.

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Avocadoes kill just about anything except humans…

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Well, apparently it is not always/absolutely true. Gerald Durrell described how his dogs ate grapes (directly from vine) without any consequences. Then, my cousins foxterrier adores chocolate. He is not allowed to eat it, so he steals. He once stole from a table and ate whole large Toblerone. Nothing happened and the dog still lives long and healthy life.

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Tell that to Quetzal and quite a number of other Central American birds. I am sure, they will be surprised.

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You are absolutely correct, @jurga_li .

The toxicity and reaction of the animal vary based on size, amount consumed health of the animal, etc. Symptoms can range from a mild stomach ache to organ failure and death. The chemical in chocolate that is most toxic to dogs is theobromine. The amount of theobromine in milk chocolate is much lower (about half) than in semi-sweet chocolate such as chocolate chips. The highest levels are found in baking chocolate, which likely isn’t being left out on tabletops for adorable little thieves.

Similarly, raisins are dried which concentrates the chemicals that cause toxicity/kidney failure in dogs. A few grapes or a few raisins are unlikely to cause severe damage, but the fact remains that in enough quantity they can be lethal.

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I live in a wine-grape growing region and long after the harvest I find dried grapes in the scat of fox, coyote, bear, deer, raccoon, etc.

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Aesop told that fable about the Fox and the Grapes. Song of Songs in the Bible also refers to foxes raiding the vineyard.

On the other hand, the mutation that allows many humans to continue to digest lactose after weaning sets us apart from most other mammals. The default mammalian condition is lactose intolerance after weaning. What would happen if for some reason a bird or a snake consumed dairy products?

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In Lithuania grass snakes (Natrix natrix) for ages were considered as sacred animals and a bowl of milk was usually put out for them. I do not know though, whether the snakes drank it, but the custom has a history of many centuries long.

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Tits and milk bottles story is well known. image

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Humans eat a lot of poisonous, unpalatable, and indigestible food, especially pre-agriculture and when wild plants supplement cultivated crops.

It’s hard to appreciate how toxic some of our food crops were before domestication. The wild ancestor of potatoes grows small bitter toxic tubers, but domestication changed all that. One of the globally important staple crops cassava must be processed to remove cyanide still. People in the northeast used to eat the young shots of the tremendously toxic american poke weed. The starchy root of jack-in-the pulpit was eaten after drying for a few weeks to break down the oxalic acid crystals. All of these foods are edible because of huge amounts of processing and cooking to render them edible and not toxic.

The list of toxic food eaten by humans is so long there is a good argument to be made that humans don’t just eat toxic food we seek it out. With the intelligence and expertise to process foods that are unavailable to other mammal commentators humans had a big step up over everything else on the African savannah and beyond.

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ASPCA maintains lists of the plants that are toxic or non-toxic for dogs, cats, and horses, here: https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants

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I am interested in this. I have known for years that avocado is fatally toxic to captive domestic parrots eg cockatiels, and have seen discussion of an incidence of this when a temporary caregiver of a tame cockatiel let it eat some of her avocado sandwich.

My dog, who eats small amounts of chocolate, raisins, and nuts with impunity, is an enthusiastic and broad-minded scavenger who will eat anything humans eat except avocado. She is not crazy about lettuce or raw tomato either, but wont avoid them in a bit of sandwich if one comes her way.
So the complete rejection of avocado really stands out.

Also, she self-medicates, I am sure, on a non-food, “toxic” (contains substances which are precursor to cyanide) plant, Haloragis erecta, seeking out young leaves with urgency at times. 11 years ago, due to a road accident she experienced a neck ligament tear, long healed but it was nearly fatal, and brachial plexus avulsion leaving her with a paralysed front leg, not painful at all as far as we can tell but it is prone to muscular spasm and contraction. She developed acute pancreatitis a week later. Appears to be fully recovered from that.
The self-medication began shortly after these events, and continues to occur occasionally.
Different topic, but indicates the dog has an instinctive sense of at least some plant effects.
So I respect her avoidance of avocado.

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Don’t all dogs and cats eat grass to clean themselves?

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Do you mean to induce vomiting? I dont know, but cats and dogs have eaten grass-like plants occasionally to induce vomiting. When she needs to vomit she eats Carex or grass.
By the way she is almost always well, and the vet says she is in “superb health”:)

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My cat loves to chow down on any and all plant matter he can find, but he leaves my Euphorbia well enough alone. Ironically, it might be easier for me to grow “toxic” plants than harmless ones…

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Our cat eats leaves of Anchusa capensis, which is related to borage.

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Well, the sweetener xylitol is toxic to dogs ( presume other canines as well ). As a lot of stuff humans consume has some xylitol in it, it may be good to check labels before sharing.

We once had a lab that got into a very large box of Easter chocolates. We came home from church and found her lying on her back in a huge nest of those little brown paper cups and groaning with a stomachache. Since it was Sunday in a small town, there was not vet available, but she was fine the next day.

Alliums (onions and garlic) are said to be toxic to cats. Lots of prepared foods, even baby food, has garlic ( again, a good idea to read labels before sharing).

Funny about the avocados and dogs. I once had a friend with a very fat beagle. She said the beagle loved avocados and would jump up and eat the avocados on their backyard tree. She said they otherwise were careful what they fed the dog, and figured the excess weight was due to eating avocados.

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