As natural habitat for animals overlaps with suburban sprawl, humans and animals come into contact frequently. With the decline in hunting of local wildlife in suburbs, generations of wild animals have lost their fear of people and are active during the day. When young tractable animals are found by people, especially infant animals who require care to survive, people hope to keep them as members of their family. There are many reasons that this is not a good idea.

First of all, in most states it is illegal to keep or handle any wild animal for any reason without a permit. This is mostly to protect people from the diseases that wild animals transmit including plague, parasites, and rabies. It also protects people from injury. Wild animals, even babies, communicate fear and hunger by biting and scratching. Mother animals, who are often nearby and unseen, may cause human injuries when their young are disturbed.

Second, wild animals found by people are most often injured by human activity; automobiles, lawnmowers, landscaping and poisoning. Keeping an animal who has been injured by humans in close proximity with humans can prevent the animal's full recovery. They may not eat and do not maintain sufficient activity to remain healthy without careful support and appropriate enclosures. 

Additionally, prey animals have a panic response to the sight and scent of danger. This translates into an inability to adapt to the constant noise and movement of most human households, especially those with domestic pets. Wild animals living in busy households are in a constant state of anxiety. Constant stress is harmful to the animal's health. 

To complicate matters, wild animals have the ability to hide symptoms of disease by changing their outward behavior. This is because most predators would recognize weak animals as sources of food. It is often impossible for people to recognize that a wild animal is ill, until very advanced disease, at which time it is unlikely that the animal will survive even with proper medical intervention.

Veterinary care for wild animals is difficult to find. Specially trained veterinarians are necessary to care for wildlife because their needs are so different from dogs and cats or livestock. For example, penicillin commonly used to treat dogs and cats will kill rabbits. If the animal needs intensive care, it may be too stressful to confine the animal at a hospital which also treats dogs and cats. Anesthetizing a panicked wild animal is risky. Recovery is also complicated because the animal will not heal well while confined but will not survive if set free too soon. Some species ability to transmit rabies prevents many vets from treating them at all.

Finally, wild animals travel extensive territories from acres to miles every day (or night) foraging for food and avoiding predators. A human household contains many dangers from fans to electrical cords. Living in a confined space and having food provided can leave a large amount of the animal's time unoccupied. This can lead to development of abnormal behaviors. It is possible to enrich a captive animal's life as zoological parks do, by offering appropriate climbing, hiding and food finding activities to an animal's safe enclosure. Most households do not have the space or resources to provide the activities to which a species has adapted for centuries. Wild animals can become suddenly aggressive during their mating season, making them impossible to handle safely under any circumstance. Especially once they view humans as part of their social group. Unfortunately, they can not always be safely neutered. 

Tragically, even for those households which can provide a suitable environment for a wild pet, animals adopted as babies adjust for several months or even years. Upon reaching maturity, these animals develop behavior which prevents them from being maintained as pets. After a lifetime of reliance on human care, these animals can not be released into the wild. They cannot support themselves, do not get along with other members of their species, and will approach people without fear. Unfortunately, zoos and wildlife rehab centers are not able to accept them. These facilities do maintain animals with injuries that prevent their release. However, these animals are able to interact with others of their species and have a calming effect on new captives. Wild animals raised as pets, can not serve this purpose.

A special situation has arisen with wild/domestic hybrids such as wolf/dog crosses and wild/domestic cat crosses. These hybrid animals present an additional problem of unpredictable behavior. Wolves and wild cats have a low tolerance for constant stimulation from human households. There is no way to predict if a particular wolf/dog puppy or cross bred kitten will inherit his wild parent's increased sensitivity or his pet parent's domestic tranquility. Within one litter, each baby will have his own mix. How do we predict which puppies must remain with the wolves and which can be kept as pets? Will the kitten inherit the domestic response to a rabies vaccine which makes it effective? If he inherits hunting instincts and can escape any fence, will we build an enclosure fulfilling enough to prevent him developing a habit of incessant pacing or self mutilation?

For all of these reasons, wild animals should not be considered potential pets. Although unusual circumstances exist, and knowledgeable handlers can make this work, it is likely that the end result will include injury to people and death to a healthy animal. Wild animals should only be handled by folks with the appropriate permits with the intention of returning them to their wild habitat.