From what I've seen, online & on tv, most of the times the baby animals are raised AT the zoo or sanctuary by the keepers and vets. The few that are taken home, go home with a senior keeper or vet.
there are a few (very few) foster/surrogate parents that aren't keepers or vets, but I don't know how they got the job or their prior experience (they most likely were keepers or vets, or have had LOTS of experience fostering animals).
Keepers need a degree and experience.
Vets need a degree and license.
To care for a wild or exotic animal in your home you would need a permit and/or license. (at least in the states, I'm not sure about other countries)
http://www.bigcatrescue.org/laws/statelawsexoticcats.htm State Laws for Keeping Exotic Cats
http://answers.yahoo.com/question/index;_ylt=AitPjMWmLPoNokVdEWVmRCXty6IX;_ylv=3?qid=20090130153945AAg67hA&show=7#profile-info-n8ovnlt5aa I want to be a zookeeper when I grow up. Help?
http://answers.yahoo.com/question/index;_ylt=ArYJr1GnJVimVoBmVT7H.27ty6IX;_ylv=3?qid=20081018193653AAE9pKu&show=7#profile-info-UY6Ibd5Iaa What do I need to do to become a vet?
http://answers.yahoo.com/question/index;_ylt=AlRwKMDkVgiI7dW7flXyIRzty6IX;_ylv=3?qid=20080924163351AAoWXvd&show=7#profile-info-pdmAHTGdaa Animal Rehaber - How do I become one?
EX 1
http://en.wikipedia.org/wiki/Growing_Up... Growing Up...
Growing Up Clouded Leopard
Professional surrogate mother Sara Bratcher raises Ming and Mei, a pair of clouded leopard cubs, in her home. After three months, the siblings will be transferred to the Asian rainforest and clouded leopard breeding program at the Nashville Zoo.
http://webpages.charter.net/sbratcher/ Sara is the mother of five grown children and was a carnivore keeper at The Nashville Zoo from 1991 to 2000. Her main interest at the zoo was the big cats, some of which weigh over 600 lbs. She is now called upon from time to time to raise baby cats for the Nashville zoo. This is done when the mother rejects them or they are "pulled" in order to make them a better exhibit animal (safer to work with and more at ease around people) or the animal is to be used in an educational program. Her favorite cats are clouded leopards and snow leopards.
EX 2
http://en.wikipedia.org/wiki/Growing_Up... Growing Up Tiger - At the Tiger Creek Wildlife Refuge in Texas...
Growing Up Cheetah - ...born at South Africa's Cango Wildlife Ranch's Cheetah Breeding Centre, are raised by a rancher ...
Growing Up Wolf - ...Caretakers at Minnesota's Wildlife Science Center ...
Growing Up Orangutan - ...Borneo Orangutan Survival Foundation where Lone Droscher Nielsen will become mother to the pair...
Growing Up Penguin - ...at the Oregon Zoo... and eggs abound. Join zookeepers Shawn and Rick...
Growing Up Zebra - Sanwild Animal Sanctuary founder Louise Joubert raises...
Growing Up Baboon - Visit South Africa's only wildlife sanctuary dedicated to the care of Chacma baboons. Four orphans are cared for by a team of volunteers...
Growing Up Polar Bear - ...the dedicated team of Toronto Zoo curators who care for...
Growing Up Walrus - ...the baby gets round the clock care from his human keepers at the Indianapolis Zoo.
Growing Up Seal - ...Alaska Sealife Center in Seward, Alaska. Dedicated staff ...
Growing Up Giraffe - ...in the care of two keepers at a northern California wildlife sanctuary...
Growing Up Moose - ...as the staff at Zoo sauvage de St-Félicien give her the care and love...
Growing Up Gorilla - ...is nurtured to health at Mefou National park by Rachel Hogan...
Growing up Giant Panda - A Panda Breeding Center...