No other name is used besides kitten. So kittens are what they are called.
You can feed your newborn dogs and cats a meal that is not from their mum after they are at least 3 months.
You call it a calf.
Dogs much like cats often eat or neglect their dead newborn.
a chickity
a chickity
A pup
calf
food
kitten
A newbee
A calf
Any newborn bear, polar or otherwise, is called a cub.