A very common occurrence in xenofiction media starring domesticated animals are for the protagonists to be strays. This adds a lot of drama to their life (having to flee from predators and humans, having to find food and shelter, dealing with rival animals, etc) but is also convenient for the writers (can create mythos and cultures for the animals, no need for curfews, no being confined by the limits of having an owner, no explanations for why the pets are outside all the time, etc).
Occasionally the pets will be born a stray but more commonly they will be a pet who runs off or is abandoned by their owner. Many times these pets-gone-strays will be bored of being a pet and jump at the excuse to leave. Rarely do their owners seem to care for their missing pet and even rarer do they actually retrieve them. The protagonist being a former pet makes them a good Audience Surrogate as they're uncertain about how living as a stray works and must learn alongside the viewer.
Characters who were originally pets will often face Fantastic Racism from feral animals for having been a pet. This can be anything from mild teasing to full-on aggression. In some works, the offspring of a stray and a pet (or a pet-gone-stray and a stray) will face hatred as well.
Stories that revolve around pets on their own usually come in two types: One where the animal flees willingly and another where they're lost or abandoned. In the former case, expect them to stay strays the entire story. In the latter case though, they'll often return to their owners or be adopted by someone else.
This is more common with cats than other pets. Dogs and cats are the most popular animals for xenofiction however, in most developed countries stray dogs are uncommon. They're either rare or are quickly caught by humans. Stray and feral dogs are seen as more of a hazard, and are more inherently dangerous (dogs can kill a human, whereas small cat species can't kill a human), than a stray cat is, though stray cats are considered more hazardous to the environment than their canine counterparts, and even feral dogs tend to be more tameable than feral cats. In contrasy, stray and feral cats are a common sight even in urban areas.
There's a bit of Values Dissonance to these types of stories. Many, such as Warrior Cats and Varjak Paw, are written by European writers. In the North Americas there is a large "Inside Cat vs Outside Cat" issue, with most animal welfare groups and cat experts citing that cats should exclusively be inside cats and that it's both abusive and bad for the environment if cats are left outside unattended. In the UK, however, the opposite is true. Leaving your cat inside permanently is seen as abusive and cats are meant to be allowed outside. Many adoption agencies won't even adopt out cats if they're intended to be inside cats. Australia is in the middle ground: letting your cats outside is a good thing, as long as it's daylight because your cat will screw the environment if they're outside at night. Feral animals do exist nevertheless, however North Americans are less likely to glamourize it.
This trope is almost always presented in a more positive light than it is in real life. In real life, pets-gone-stray do not do well in the wild. They don't have the survival skills of feral animals and often times get loose in places completely unsuitable for their species. For example, stray and feral chickens do well in Hawaii, because it is tropical like the red jungle fowls (ancestor of the domestic chicken) native habitat. Stray chickens don't do so well in Northeastern and northern Midwestern US states and Southeastern Canada because the climate is very different from that of their ancestor.
If they do somehow make it past their first few weeks without being killed or rescued, they'll likely have less-than-fortunate lives filled with hunger, parasites, and danger. Not even feral animals live long (feral cats have a lifespan around 3-5 years in contrast to pets who live 13-20 note ), nevermind pets who have to learn survival skills as adults. Alas, watching a dog die of starvation isn't exactly fun so most stories (even darker ones) whitewash the harsher aspects.
Contrast with From Stray to Pet, where a stray animal is adopted. Compare to The Runaway, Stray Animal Story, and Raised In Captivity (for when a wild animal - like a bear or wolf - is raised in captivity and let go into the wild later on).
- The start of Ginga: Nagareboshi Gin is a tale about a a boy and his dog, Gin. After a few episodes Gin joins a pack of feral dogs and the series changes focus to being about him.
- Blue from Wolf's Rain is a wolf-dog. She originally hunted wolves alongside her master, Quent Yaiden, however when she learned she was half-wolf she joined the wolves. Blue subverts the usual cliches as she has no issue living in the wild nor is she the lead.
- An episode of Yo-Kai Watch revolves around Jibanyan helping a lost kitten named "Kitty" get back to its owners.
- In Fire and Shadow, Rusty is a pet kitten who is forced to join a cat colony in the forest. He gets attacked by ThunderClan cats (more specifically, Tigerclaw) while exploring and is narrowly saved by their rivals, ShadowClan. There's no way for Rusty to go back home besides going through their territory again and risking attack, so his best option is to stay with ShadowClan. Later Rusty, now called "Firepaw", has a chance to run back home but he decides to stay and help his friends evade an attack instead.
- Warriors Redux:
- The founder of ShadowClan was a molly named Rowena. She was a former pet who either ran away or was kicked out. Rowena's upbringing as a pet made her unusually caring but also quite naive, resulting in her getting taken advantage of several times. She was empathic and as a result she created a Clan full of the weak and the ostracized.
- Bluestar and Redtail have been studying Rusty for some time. When he wanders into their territory, they have Greypaw attack him as a test. Rusty passes the test and is asked to join ThunderClan. Rusty decides that since his owners only recently brought him that they aren't attached to him, so they'll move on quickly and get a new kitten. With that he joins ThunderClan the next night.
- In Paradise, Celestia and Luna's father was a pony who escaped his abusive humans and joined a wild herd.
- Blood! Rusty AU: Fearing that his owners will turn him into an inside cat and take him to the Cutter, Rusty decides to run away to the city. There he comes across a colony of alley cats and joins them.
- Leafie, a Hen into the Wild is about an abused hen living in a factory farm who one day manages to escape. She escapes to the local marsh and lives amongst the wild animals. Leafie ends up adopting a duckling after his parents are killed by a local weasel, and the film is mostly about her and her son Greenie.
- Lady and the Tramp
- In the original film, Lady is a pampered pet Cocker Spaniel who leaves her home early on. She doesn't actively seek to become a stray though and ultimately returns home after having a fling with the Tramp. In the end, the Tramp himself is taken in by Lady's family and becomes Lady's mate.
- In the sequel, Lady and the Tramp II: Scamp's Adventure, Lady's and Tramp's only son Scamp is a rowdy puppy who wishes he could live on the streets. His father Tramp has settled in nicely to life as a pet and is very against his son's desire. One day Scamp escapes from home to join up with a local gang of junkyard dogs. He befriends a puppy named Angel, who unlike him wants to become a pet. Scamp soon learns that being a stray isn't as fun as he thought it would be, and in the end both he and his girlfriend return to his owners.
- Bolt is about a White Shepherd named Bolt who accidentally gets lost. Besides having no experience on his own, Bolt also believes he's a superhero due to being raised on a TV show since puppyhood. He befriends a stray cat named "Mittens" and a hamster named "Rhino" that help him survive. Ultimately Bolt returns to his owner and his friends get adopted by her too.
- In The Aristocats a molly cat and her kittens are left to die by a butler who is mad that their wealthy owner gave her cats her inheritance and not him. Duchess and her children must find their way home with the help of a stray named Thomas O'Malley. Ultimately they return home and Thomas gets adopted too.
- In the end of Spirit: Stallion of the Cimarron, Spirit is returned to his herd in the wild alongside his human-raised mate, Rain.
- In Balto II: Wolf Quest, Aleu is the only one of Balto and Jenna's puppies who is not adopted. This is due to the fact she looks more like a wolf than a dog (her father being a wolf-dog). She ultimately ends up leading a pack of wolves.
- Flushed Away is about a pampered pet rat who is accidentally lost in the sewers of London.
- Rango is about a pet chameleon who gets lost in the desert and wanders into a Western town inhabited by Civilized Animals. There he passes himself off as a tough guy and is made sheriff.
- Homeward Bound: The Incredible Journey: Two dogs and a cat are left on a farm while their owners are on vacation, but not understanding they think their family is in trouble and escape to trek hundreds of miles across the Sierras to return home.
- From Stray to Pet appears in Warrior Cats but it is much more common for this to occur. The Clans look down upon "kittypets" (and it's against the Warrior Code to interact with humans and act like a kittypet), and thus it's rare for them to be taken in by humans permanently; however, many kittypets leave their owners to join the Clans:
- The series starts out with a kittypet kitten named Rusty who finds his life as a pet bland and has dreams of being a stray cat. (Appropriately, the first book is named Into the Wild.) One day he ventures away from home and comes across three cats from ThunderClan. Due to Bluestar recognizing Rusty as being the cat who will likely fulfill a recent prophecy she has seen, she allows Rusty to join the Clan and renames him "Firepaw". Firepaw is renamed "Fireheart" once he finishes his warrior training and ultimately becomes "Firestar" when he becomes the new leader of ThunderClan.
- Fireheart brought his nephew, Cloudtail, to ThunderClan as a young kit. His sister, Princess, wanted to choose what happened to her firstborn as she knew her owners would choose where her other kits went. Cloudtail was ostracized by others for his kittypet heritage but didn't even know he was adopted until he was almost of apprentice age.
- Firestar's half brother Scourge was a kittypet named "Tiny", who fled his home after his sister told him that any kittens that humans didn't want were thrown into a river. Later on, Scourge's littermates Socks and Ruby, who had been adopted by Twolegs, became strays when their Twolegs abandoned them after moving away. The two begged their brother Scourge to take them in, but he chased them off. It's never clarified if Socks and Ruby were eventually adopted again or if they lived as loners for the rest of their lives.
- Sasha's owner was sent to a nursing home. When she realized he wasn't coming back, she became a rogue cat.
- Purdy became a rogue after his owner died.
- Millie left her home to help Graystripe find ThunderClan and join it herself.
- Many of New SkyClan were kittypets who left their homes to join the Clan.
- Violet's kits were born as kittypets however they wanted to become warriors. Violet let Ravenpaw take them to New SkyClan.
- In Windrusher, a cat named Tony is abandoned by his owners. In his effort to find them, he is nicknamed "Windrusher" by other animals.
- In The Call of the Wild a sled-dog named Buck ends up acting increasingly wild until he joins a wolf pack.
- Varjak Paw is about a kitten named Varjak who is forced to leave his pampered home in order to save his family. While Varjak is quite clueless about life outside his home, in many respects he quickly becomes more adept at living as a stray than his peers. While he doesn't know the social in's and out's of being a stray, Varjak is able to unlock the "Way" which allows him to hunt animals. Most of the stray cats in the city can't hunt and instead scavenge off of humans.
- Survivor Dogs:
- A stray dog named "Lucky" (who was born a pet) manages to escape his enclosure at a pound after an earthquake. He finds out the humans have evacuated the area and left their pets behind. Lucky and several other abandoned dogs form a pack. The Leashed Dog pack, which eventually became the Wild Dogs pack, spent a long time trying to get used to the fact they'll never see their longpaws again. Sunshine, a Maltese and an Omega, was the most attached to hers and will likely never get over them.
- Sweet is a swift-dog (Greyhound) who lived as a racing dog until she was deemed too old. Instead of killing the dogs or giving them to shelters, the dogs were let loose into a pack. The rest of her pack died in the Big Growl.
- Marco from Guardian Cats And The Lost Books Of Alexandria is a pet cat who can read. After he becomes homeless, he meets a group of cats entrusted with guarding a group of mystical books. An elder chooses Marco as the next in-line to guard one of the most special books.
- Stray by A.N. Wilson is about a cat named Pufftail throughout his life. He has been owned by several owners (both abusive and kind), been abused in a lab, and lived as a stray on the streets.
- Dogs of the Drowned City stars a German Shepherd named Shep who, after a hurricane forces the humans to evacuate, has to leave his home and venture into the surrounding area. Along the way he befriends other dogs who are now on their own.
- The Incredible Journey is about a Labrador Retriever named Luath, a Bull Terrier named Bodger, and a Siamese cat named Tao who get lost in the Canadian wilderness and must find their way back home. It and its 1963 film adaptation was the inspiration for the 1993 film Homeward Bound: The Incredible Journey.
- The Good Dog by Avi is about a Malamute named McKinley who meets a wolf named Lupin. Lupin is trying to persuade dogs to leave their owners and join her pack.
- Doglands by Tim Willocks is about a puppy named Furgul who is born into a camp for racing Greyhounds. When the owner finds out that Furgul is only half-Greyhound, he tries to kill him but Furgul escapes into the wild.
- The Wild Road is about a pet kitten named Tag who begins having prophetic dreams. He goes on a journey to bring the queen and king of cats to Tintagel before the spring equinox.
- The children's book Dear Hound is about a Deerhound puppy named Alfie who gets loose and gets lost in a forest. He survived on scraps of food from garbages and is helped by a pair of foxes until he returns home.
- The Last Dogs is a book quadrilogy about humans leaving their pets behind because of an outbreak of a virus called Praxis. The main protagonist, a Labrador retriever named Max, sets out onto the streets and into the wilds (along with a dachshund named Rocky and a Yorkshire terrier named Gizmo) as they look for their humans and solve the Praxis mystery together.
- A Dog's Way Home is about a dog named Bella who travels thousands of miles trying to find her way back to her owner Lucas. Throughout her nearly three year journey, Bella ends up living in the mountains with a cougar cub and getting caught by various humans who sidetrack her journey and take her to various states until she finds her way back home.
- Life After People has several instances of this happening to domesticated pets:
- Dogs can be pretty good survivors once the humans are gone, though some still struggle to survive:
- A Lacy Hound (a dog with the blood of scenthounds, sighthounds, and wolves) uses all she can to scavenge for food in her late owner's house. Once the food and water run out, she joins a pack of former pet Lacy Hounds, and they roam over the plains of Texas, hunting wild pigs.
- Bo the Portuguese Water Dog, a pet of President Barack Obama, makes his way from the White House to Chesapeake Bay. Eight years after people, and he's lived well by himself, fishing for clams, crabs, and fish.
- Sadly, not all pets make it on their own. A Labrador retriever guide dog tries living on his own near a grocery store. Once the food runs out, however, the retriever tries scavenging for food since he doesn't know how to hunt, and he slowly dies from starvation.
- Greyhounds used in racing start running wild, chasing rabbits and other prey. But because of their competitive attitudes and thin skin, their future looks bleak.
- German shepherds strike out on their own from their military base. While the males are unneutered and can pass down their bloodline, the females are spayed and cannot breed. Several German shepherds still survive, but only on small islands off the coast of California.
- The Queen of England's corgis thrive for six months inside the empty Buckingham palace. Fifty years later, they've escaped into the wild and bred with other dogs until their corgi line is lost. They've thrived well in Great Britain due to the extinction of more savage larger predators (like wolves and bears) and the absence of rabies.
- Anatolian shepherds are a rather conservative breed in a world without people, refusing to breed with other breeds of dogs that would harm their sheep, but they continue living in the wild alongside the sheep.
- There are plenty of cats that begin learning to survive in skyscrapers, evolving very differently. Those that still live on the ground eventually become top predators in their area, growing to the size of bobcats.
- Horses belong to the New York City Police Department start roaming around the city, looking for food in garbage cans. Once the cities start to crumble, they leave the city and head to the beach, where they eventually evolve into shorter but stockier and beach-dwelling horses.
- Parrots escape into the wild and pass down their knowledge of human words several generations.
- Dairy cows struggle to survive without their human handlers milking them and helping them give birth. Those that do survive eventually escape to the prairies, where they share the grassy areas with bison.
- Unlike ordinary cattle, Texas longhorns survive very well without humans.
- Dogs can be pretty good survivors once the humans are gone, though some still struggle to survive: