This depends on what type of animal you are talking about. Orphaned wildlife that isn't found by humans tends to be abandoned and often dies in the wilderness. Sometimes humans can intervene and take orphaned wildlife to a wildlife rehabilitation center, although this is rare. Orphaned domestic animals under the care of a dedicated owner will often either be fostered out to another mother in the same area or may be hand-raised by the owner. Unfortunately, there are some owners that will just abandon orphaned baby animals and allow them to die; this is often considered criminal animal neglect.
Rearing of animals, means raising animals. If you take in an abandoned baby squirrel, you will be rearing or raising the baby.
If the baby hamster was abandoned by its mother, its probably not healthy.
A mother is someone who takes care of a baby
The mother of a baby spider monkey takes care of it.
No
Baby worms receive no parental care. They are on their own.
A mother is someone who takes care of a baby
Nobody takes care of them - they are on their own from the moment they hatch from their eggs.
A gynecologist takes care of women's reproductive health, an obstetrician takes care of women while they are pregnant and deliver the baby. A peditrician takes care of the baby.
If you are referring to baby animals that are abandoned by their mothers, they are usually called "orphans" or referred to as orphaned. Once it is clear the mother either, isn't capable of raising the baby, or will not raise it, then usually the keepers will take over the responsibility of hand rearing the baby. If you are referring to the animals that are sometimes abandoned at the zoo, they are often referred to as the unwanted, or abused. Most are in poor health and in need of serious medical care. After they recover, if there isn't a place for them at the zoo, they will normally be moved to another zoo or a shelter.
People help animals (such as pets) which owners abandoned and/or could not afford to take care of their animals
the mother