Should the Pokémon examples really be on here? The egg one, maybe, but the ones about their diet... Sure Meowth looks like a cat, and Pikachu looks like a rodent-lagomorph-mix, but they are not cats/rodents/lagomorphs. Sure a real life pet should usually not eat chocolate, or sugary foods, but "electric furry beast that lays eggs" and "sentient rock" might well be perfectly capable of digesting those things.

You forgot to point out that Gidget from The Secret Life of Pets was in a dish washer at one point.

I added something for Between The Lions.

Deleted:

* This infamous Tumblr post, where a dog owner proudly posts a photo of their dog which they feed a solely vegan diet. Cue another user pointing out that the "excited" dog actually looks miserable and malnourished, and writing a short essay on why denying meat to your dog is a very bad idea.

• The problem is that not everything the angry guy says is correct, and some of it is actually rather stupid.
  • He says several times that dogs don't produce Cellulase, which is the enzyme that breaks down Cellulose. The problem is no vertebrate produces it. It is produced by bacteria in the gut. So if cows pancreas doesn't produce it, what makes you think that a dog's would?
  • Secondly, he mentions that a dog isn't capable of getting proteins out of carbohydrates. A. this isn't how herbivores get their protein, and B. neither are humans. This means vegans must consume food that isn't starchy, i.e. nuts and legumes.
  • Finally, there is in fact plenty of evidence that dogs AND wolves are in fact omnivores. They eat a lot of berries and roots in fact. The only thing dogs can't handle seem to be grasses and grains, in fact.
• It gets worse. Take another look at the picture; the tray that the owner is holding obscures every part of the dog's body except for her head (and even with just her head showing, she looks like she's been through the wringer several times). This could be a coincidence, but it's also very possible that the owner positioned the tray like that on purpose in order to hide the dog's obvious malnourishment. If this is true, it would mean that she knows that the diet is bad for the dog and is still forcing it on her.

Disputs over whether it's an example or not do not belong on the main page.

is it just me or is there a lot of "You shouldn't do this." Instead of "here's an example of the trope." on this page?

Just wanna point out that the whole Cats and dogs can't eat ice cream/drink milk thing isn't entirely true, it might upset their stomach a little but that happens anytime they try new foods, in fact(outside of chocolate) vets even recommend giving the pet ice cream if they need to gain weight.

I feel like "Artistic License" is too nice of a term for works that encourage people to accidentally kill their pets.

Deleted the "General" folder, Examples Are Not General, for one thing. Preserving it here because it's a lot of material, it could be made into a Useful Notes page or some of it could be worked into the description.

folder:General

• Goldfish bowls:
  • Yeah, funny thing, goldfish don't live very long in goldfish bowls. They thrive better in aquariums, artificial ponds or both. Sadly, this one is still widespread in Advertising, as many companies still market small bowls as being for goldfish.
  • A baby turtle needs a lot more than a little dish of water with a fake island in the middle. Most aquatic species need deep water for swimming, lights to bask under, and some form of filtration.
  • Betta (a species of small fish) doesn't enjoy having company. Sometimes, people try to keep a male and female betta in the same container, even when they're not breeding. In actuality, it's very likely that one of them (most probably the female since they're generally smaller, although it could be the male) is going to be violently attacked by the other eventually. You can keep females together, provided you a) have a large container b) have at least 5 of them and c) don't touch or move anything in there (otherwise, they have to figure out their pecking order all over again, which is always a stressful week or two for both fish and owner.) And sometimes even that doesn't work out. Bettas (for the most part) just don't play well with others. They aren't called Siamese Fighting Fish for nothing! Like other fish, they prefer aquariums (Unlike goldfish, they can be kept in smaller ones provided that they are maintained) and really shouldn't be kept in the tiny plastic containers they are sold in.
• Animals and tails:
  • Almost no animals should ever be picked up by their tails. Most animals only use their tails for balance; tails usually aren't strong enough to safely hold the animal's entire weight.
  • Mice and Rats may be held by the base of the tail and no longer than a couple of seconds. Not only is it painful, but there's a risk that the tail's skin will tear under the animal's own weight and peel entirely off. This goes double for animal wranglers who allow actors to hold rodents in such a dangerous way during filming. (The mouse can survive the experience with less pain and for longer, BUT ONLY THE BASE OF THE TAIL.)
  • Some lizards' tails will actually break off if pulled on too hard, and then wiggle around frantically for several minutes after being detached. This isn't accidental—predators are likely to grab the lizard by its tail, and letting it pop off often distracts the predator long enough for the lizard to escape—but it's not a fun experience for the lizard either way.
  • In the case of mammals, the tail almost always contains part of the animal's vertebrae, so pulling on it or otherwise putting massive strain on it can have horrifying results for the rest of the animal's spine.
  • Holding a turtle by its tail, especially a snapping turtle, is a really bad idea. Not only is the turtle strong enough to escape your grasp, which may hurt it when it hits the ground, it can still bite or claw you if you're only holding its tail.
  • Although you still shouldn't pick it up by the tail, the West Highland White Terrier has been bred specifically to have a more robust tail than other dogs so you can grab it to pull them out of narrow tunnels if they get stuck.
• Many illustration of magic tricks such as the old "Rabbit-Out-of-a-Hat" trick show the magician holding the rabbit up by the ears. This act is quite painful, much like pulling a person by the ear is, and in fact old-school magicians hold rabbits like that because it's painful. Rabbits aren't very entertaining if they're just being held up limply — when a rabbit is being held by the ears, it kicks and moves around, which is much more "appealing" and shows the audience that it's a real, live rabbit. Neither should one hold the rabbit by the scruff of its neck. Scruffing a rabbit isn't too dangerous if it's done properly, but most bunny care books will advise you not to try it, because doing it properly can be very tricky, especially if the bunny panics.
• Hamsters:
  • Any show portraying hamsters (most particularly syrian hamsters) living happily in pairs or groups. A normal syrian hamster would eventually kill even a litter-mate, as they are loners by nature. Male-female pairs may occasionally work, but would lead to the female breeding continuously till she dies of exhaustion.
  • In the History Channel's documentary Hippies, the narrative of how LSD was invented is backed up by footage from early experiments with the drug, including a shot of a hamster trying to chew its way through the bare metal mesh at the bottom of its cage. Exposed wire-floor cages are terrible for pets' feet. (Also a case of You Fail Biology Forever, as the context implies that the animal is chewing the wire only because it's drugged out of its mind, but gnawing on objects and attempting to dig its way free is perfectly normal behavior for a hamster, and any other rodent, that feels frustrated.) Research animals were often kept in bare metal mesh cages back in the day. Things have gotten MUCH better nowadays.
  • Really elaborate hamster habitats, with multiple chambers and plastic tunnels running throughout a room or even through walls, are virtually impossible to keep clean. A single hamster (the only safe option; see above) will choose two or three chambers as its sleeping place and larder, then visit the others only to use them as latrines.
• Rats are extremely social animals that quickly become stressed if left alone for long. Keeping a rat as a single pet is quite cruel, as it'll need at least four hours of contact with its human owner per day just to keep from becoming a basket case.
• Mammal pets and milk:
  • Humans are perhaps the only adult mammals who can digest milk, and lactose tolerance is a mutation largely restricted to peoples who've had domestic cattle for a long time—as in, "longer than recorded history". After weaning, the vast majority of mammals completely lose the ability to digest milk and will get digestive problems if they have too much.
  • Any time a cat is fed straight ruminant milk. Especially if it's a kitten. Cats are always lactose intolerant; some less than others, but any more than a very small amount will cause an upset stomach and diarrhea. Watering down the milk can help make it easier to digest, but it's not necessarily 100% effective. You can give your cat either goat's milk or special pet milk available at pet supply stores (this is different from the milk replacement formula for kittens). Also, cream and yogurt are less harmful for cats than regular milk. So long as your cat doesn't throw up or display other digestive problems, you can give small amounts of regular milk as an occasional snack, but it's still not recommended.
  • Same goes for dogs for that matter; dogs should not be given milk in more than tiny quantities. Being partial omnivores, some (very small numbers) canines can process milk, but most experience acute intestinal symptoms including gas, diarrhea or vomiting. That's because most dogs can't digest lactose well at all; others who can could only be given watered down milk—for example, 1/2 cup of milk & water is more than sufficient as a treat to large dogs while 1/4 of milk and 1/4 water for medium, while small dogs shouldn't even drink that small amount.
  • Mice and rats are also often fed milk by their owners, according to a book on rodent care: "...this is fine in small amounts like thimble sized cups for mice and bottle cap sized for rats for a once in a while treat it is alright if 2% or 1% milk." While most mice and rats are omnivores, and like their wild cousins they eat not only seeds, grains, nuts, berries and other fruits, but also worms, insects, fish and eggs — but milk is not a normal thing. In fact, lactose can give them gas and digestive issues just like anyone who is lactose intolerant, so while it seems OK, it's probably not the best idea to feed your mouse or rat milk even in the 1% grade.
• Piranhas need an enclosed tank. Not to prevent bad guys' Mooks from falling in, but because they're notorious for jumping out of the aquarium to their deaths when kept as pets.
• Whenever an iguana is portrayed as being fed live insects (usually flies). Unlike many lizards, iguanas are herbivores. They prefer fresh leafy vegetables to creepy crawly insects.
• Chocolate:
  • Humans metabolize theobromine (a bitter alkaloid compound found in the cacao plant) much more quickly and efficiently than most animals, and for most animals it's very toxic and potentially fatal, especially if they get hold of dark chocolate. Most vets will flat out state that animals shouldn't have any, ever, no matter the concentration, just to be safe. See here for more. It's also possible for humans to get poisoned by the theobromine in chocolate, but this is generally only a real danger for the elderly. Healthy people would have to consume a very large amount of it for this to happen and would probably throw it up from eating too much in general before any negative side effects could set in.
  • Most media are aware that chocolate is toxic to dogs, but not cats. Cats are, in fact, even more sensitive to theobromine than dogs, but unlike dogs cats are obligate carnivores. Due to lacking a necessary gene, felines cannot taste sugars or "sweetness", and thus have no interest in such a sugary foodstuff. Interestingly, rats can tolerate even more theobromine than humans, but it's still unhealthy for them due to the caffeine content.
  • Justified Trope if it's British media. "Dog chocolates" still appear in UK-published pet manuals (and low-concentration chocolate like milk is only harmful in very large amounts). In other words, the dog is very unlikely to die from eating a chocolate-chip cookie or even feel mildly sick but a five-pound baking bar would be cause for concern.
• Alcohol and coffee are much more toxic for a dog or cat than for a human. While dog owners may see the animal licking a small amount of spilled coffee or beer and assume it will be fine, in large quantities (an entire cup of coffee for a medium sized dog) it may kill the poor animal, while it just distresses a human. Hops in beer is also toxic. It's safer to never give the dog coffee or alcohol.
• Holding a cat by the scruff of its neck without supporting the hindquarters at the same time is bad. Mother cats carry their kittens this way, but it's generally advised that owners shouldn't even try it. Kittens held this way instinctively freeze so that they won't hurt themselves by squirming around too much. If you know exactly what you're doing you can gently pinch this area to evoke the same response in adult cats, but never actually pick them up by it. Adult cats, save for unusually tiny ones, are far too heavy, and being picked up like this strangles them. The key is that the hind legs need to be supported as well, but in most cases it's best to leave scruffing to your vet - an upset cat might thrash even if scruffed correctly, and thus can still injure themselves (and the offending human!).
• Fish:
  • Many novice fish owners will keep several different species of fish in the same tank. Now, while this may be fine with some species of fish, many fish do not thrive well with others. These can range from fish that are simply too aggressive to be kept with other species, to them not having the same tank requirements. Alas, expect a lot of shows/movies/etc. to show a standard-size fish tank with multiple species that would most likely kill one another in Real Life.
  • Likewise, many forms of fiction depict people feeding their fish standard "fish flakes" or "fish pellets". In reality, many species of pet fish require a specialized diet (see below for a specific example). Not only that, but novice fish owners tend to think they only need to feed their fish a large meal once a day. This can actually cause severe digestion problems in certain species of fish. It's recommended that owners feed their fish small meals at least 2-3 times a day.
  • Many depictions of fish tanks generally show them containing nothing but gravel (or sand), water, and the fish. In reality, it's best to add small plants (fake or living) and/or decorations that allow the fish to explore and hide. This is for three reasons. First, fish do get bored. Without an area for them to explore, they will end up doing what is known as "glass surfing" in which they will repeatedly slide up and down the same side of the tank. Second, fish get stressed out if they don't have an area where they can hide. Many pet species of fish tend to prefer areas where there are plenty of places to hide from predators, much like how they would live in the wild. And, finally, adding decorations helps more territorial fish feel like they have their own space. They are less likely to attack one another than they would in a non-decorated tank.
• Pufferfish:
  • People who own pufferfish tend to want to see them "puff up" like they do in the movies and cartoons. The problem? This causes severe stress to the animal (Remember, pufferfish inflate themselves to frighten away predators) which can shorten its lifespan. Not only that, but pufferfish can be seriously injured or even die while puffing up.
  • Many novice pufferfish owners tend to feed their pets other fish. While puffers will occasionally eat other fish, their primary diet consists mainly of clams, snails, crabs, shrimp, and other shellfish. In fact, it's recommended that pufferfish owners primarily feed their pufferfish shellfish in order to keep the puffer's beak healthy (A pufferfish's teeth are formed into a beak-like shape that grows throughout its life. Without shellfish to wear said beak down, the pufferfish would eventually starve).
  • Keeping more than one pufferfish in a tank is also a common sight in pet stores (and in fiction). Although juvenile puffers may sometimes swim in groups (often as a way to keep safe from predators), adult puffers are solitary and are aggressive towards one another. Unless you're trying to get Mr. and Mrs. Pufferfish to breed, or if you have a large enough tank, it's best not to keep more than one puffer in a tank.
  • Often, novice pufferfish owners will keep Green Spotted Puffers (the most commonly kept pet puffer) in freshwater and often with goldfish. There are two major reasons why this is a bad idea. First of all, GSP are tropical fish. They prefer warmer water compared to goldfish. Second, and more importantly, goldfish are freshwater fish. GSP, on the other hand, are brackish water fish. This means that GSP live in saltier water than goldfish. While GSP can live in fresh water, it greatly reduces their lifespan by several years. They are not compatible with one another.
    • Likewise, some pet owners (and some pet stores) tend to put GSP with the similar-looking Figure "8" Puffer. While juveniles of both species can live together for a while, they are not suited for being long-term tank mates. For one thing, like with the goldfish above, Figure "8"'s are freshwater puffers whereas GSP are brackish water puffers. Also, GSP grow to be larger than Figure "8" puffers and will attack them out of territorial instinct.
  • A common sight in various forms of media and in various fish tanks in Real Life is to see a puffer sharing its home with other species of fish. Now, while puffers may tolerate certain other species of fish, they are actually notoriously territorial. Even the small ones are known to viciously attack other fish to the point where there have been accounts from fish owners of their puffer (or puffers) actually attacking and killing fish much larger than itself.
• Many people assume that it's ok to be loud around snakes. This is due to the common misconception that snakes are deaf. In reality, snakes can hear, but since they lack ear holes they pick up noise by sensing vibrations in the air or through the ground through their jaws which are then carried to the inner ear inside the head. Loud noises can actually cause severe stress in snakes. Imagine how annoying it is when speakers play really loud music (to the point where you can feel the vibrations coming from said speakers), and what it must be like for an animal that "hears" by feeling vibrations.
• Many shows/cartoons/etc. feature a child (often a male) showing off his (or sometimes her) pet amphibian (often a frog, but newts/salamanders and toads are sometimes featured) by carrying it around or by it poking its head out of the child's pocket. In reality, amphibians have very sensitive skin and it's generally recommended that they are NOT handled unless you have rinsed your hands of any soaps or whatnot that could potentially injure said amphibian.
  • On the subject of amphibians, several novice Axolotl (a fully-aquatic salamander native to Mexico) owners tend to keep several in an aquarium at once. Axolotls are cannibalistic and, unless they are roughly the same size, will attempt to eat one another.
    • Novice owners also tend to put gravel (or decorative rocks in general) at the bottom of an Axolotl tank. Unfortunately, since Axolotls feed by sucking water/food into their mouths and swallowing them whole, they tend to accidentally swallow said stones. This can cause severe digestion problems and even death. It's recommended to use either fine sand or simply no covering at all on the bottom instead.
  • Many shows have depicted a small child's pet frog accidentally slipping out of its owners hands and landing safely on the ground. While some frogs can safely land on the ground from a certain distance, dropping a frog in real life usually results in something similar to what would happen if you were to drop a water balloon only messier.
• Shows/movies/etc. in general tend to depict a pet snake being fed live food. Although it's debatable whether or not it's humane to feed a snake live food (Let's just leave it at that...), it is generally considered more dangerous to the snake. This is because a live rat, mouse, or even rabbit will still struggle to escape and can cause injury to the snake. It's generally recommended to feed snakes frozen food (thawed to body temperature) instead.
  • Live food can be dangerous for the owner, also. Snakes presented with live food will likely be considerably more aggressive and more likely to bite for some time afterward, due to having its hunting instincts triggered.
  • A common sight in media is to see a rather bloated-looking snake due to it eating a large meal. In reality, snakes do sometimes die because their stomachs rupture from eating too large of a meal. Unfortunately, novice snake-owners tend to not know this and think their snake only needs one very large meal a month to sustain itself. Yes, snakes can go for a long time without food (especially after a good-sized meal). But, it's safer to just feed the snake a modest meal more often (how big and how often depends on the size and age of the snake).
• Anyone attempting to feed an obligate carnivore (such as a cat or ferret) on a vegetarian or vegan diet is all but ensuring that the animal will starve to death, even if it actually eats the food. Obligate carnivores need the proteins found in flesh to survive. A vegetarian or vegan diet can be pulled off for canines, but only with special vitamin supplements and close monitoring. Please don't try it without the help of your vet (and really, if meat-eating is an issue for you, consider sticking to herbivorous pets - it's just simpler and easier on the animals). One couple in Melbourne nearly killed their kitten while attempting to force the cat to go vegan.
• In various forms of media, chameleons are shown changing color almost instantly to pretty much any color/pattern the background happens to be. This causes chameleon owners to want to see said color changing for themselves. While chameleons can change color, it's actually to indicate mood, health, body temperature, and for territorial displays rather than for blending in. In fact, it's actually a very bad idea to force a chameleon to change color since it can actually stress out the reptile and make it very ill.
• A common, romantic depiction of raptors (eagles, hawks, falcons, etc) is to have the bird sitting on the hand, arm or shoulder of its owner, ready to fly off at command. In reality, this is a terrible idea. Raptor talons are designed to tear meat to ribbons—they can easily cut through human flesh and clothing. Most handlers wear heavy leather to protect themselves. It's also very strongly recommended that you keep the bird attached to you via rope. Oh, and never pet a bird of prey. They hate it. (With the notable exception of some hand-raised owls.)
• Llamas are so fluffy and soft-looking that people who know little about them are likely to try to cuddle with one. This is a terrible idea, as llamas are defensive about their personal space and may spit or bite if manhandled.
  • The same holds true for other livestock such as sheep, goats, cattle or pigs. As nice as it would be to cuddle them like a cat or a dog, they don't like their personal space invaded and interpret it as being attacked by a predator.
• It's quite common in media for birds to eat out of a human's mouth. This is extremely dangerous in real life, as human saliva is toxic to birds.
• And on the topic of birds, it's very common in media (and definitely Truth in Television) to see people feeding ducks and other birds bread. In reality, this is deadly for birds — they can't digest bread at all, but it swells in their stomachs and makes them feel full, with the result that they starve to death because they don't go looking for real food. In addition, it makes the birds associate the areas where they get fed with getting regular food; as a result, some of them fail to migrate in the winter, which results in them dying from the cold temperatures and lack of food. Never feed a bird bread.
  • For that matter, bread has caused deaths among pet rodents when it swells up inside the throat, causing choking. Bread should be toasted until it's crispy before giving it to small pets.
• While rabbits will eat carrots, feeding them the orange roots of carrots is a very bad idea — give them the leafy green tops, and eat the orange root yourself! The bulk of a rabbit's diet should consist of dried grass hay (alfalfa is too rich) and a wide variety of fresh greens, of at least three varieties a day and varying which three (but not iceberg lettuce which has no nutritional value and too much phosphorus). The typical rabbit may require a few cups of greens and hay per day. Pellets should really only be fed to juvenile and pregnant rabbits, and anything else (including carrots) shouldn't exceed a tablespoon per day, even less for small breeds.
• Fictional accounts that depict pets of different species getting along, simply because they share the same owner, can be a potential recipe for disaster if the pets in question are natural predator and prey. Despite what a story or cartoon might say, assume terriers and ferrets will always attack smaller furry animals, rats will always attack small birds or reptiles, and pond turtles will always attack fish.
• Feeding dairy products to birds and reptiles, which cannot digest lactose like mammals.

Should there be a section in 'General' about anybody dense enough to give anyone a surprise pet?

Reader's Digest (!) once had advice on getting a cat to learn tricks. They advised using chicken-flavored baby food as a treat. Problem: Baby foods often contain onion powder as a thickener. The sulfoxides not only mess up the red blood cells, they play merry hell with the liver, preventing production of a vital enzyme.

And apparently guinea pigs can be poisoned by garlic and onion as well. (Just read that.)

PS. I did email RD about the section's stupidity. I've yet to see anything straightening the matter out.