There are many cases and information to talk about it, but here we mention briefly four cases. An invitation to comment and to keep searching.
Shortly after the end of the world-wide well knowing Harry Potter film franchise, animal shelters in the United Kingdom were overwhelmed with the retirements of owls by their owners. The owls are a group of birds belonging to the order Strigiformes with 200 prey species. Most of them are solitary and nocturnal. Owls hunt mostly small mammals (as rats and bats), insects, other birds and even fish. These animals can live over 20 years.
The bird sanctuary Owlcentre in Corwen, North Wales, spent 6 animals to care for more than a hundred. The main causes were the lack of interest of the owners, the high cost of maintenance and the rigorous daily care because this animals need exercise their wings by long flights. But more animals were left into the wild, without control, assuming a serious problem for other species and the environment. If there is an excess of predators, all existing trophic relationships can be loosen, even with the loss of biodiversity.
Something similar happened with the popular cartoons Teenage mutant ninja turtles. They awoke in children the wish to have turtles as pets. Turtles are reptiles of the order Chelonii or Testudines, characterized by a special shell fused to their ribs. The problem is that some species acquire great size and very long-lived*, which equals to say that it survive to the childish whim.
*In fact, recently discovers show that a turtle’s organs do not gradually degrade or loss efficiency over time as occurs with most other animals. Organs like liver, lungs and kidneys were almost indistinguishable from those of immature counterpart. Based on these observations, the genetic researchers focus on the turtles genome looking for the longevity gene.
There are other examples, more recent in time, as the high number of Husky dogs abandoned since Game of thrones and Twilight saga started.