When a couple lavish all their parenting impulses on a pet, that pet is a furkid.
furkid (noun) - a pet such as a dog or a cat that is treated like a child by its owner.
"We are thinking of adding another furkid to our family."
'Couples like furkids because they usually don't live long enough to need expensive private schools. And their friends like furkids because, unlike real children, you can plausibly claim to be allergic to them.' (ABC Network, Australia, 2004)
Those adults who don't want to or haven't been able to have children but have decided to share their lives with other creatures, might talk about their furkids. This noun, with alternative forms fur kid and fur-kid, is used to refer to a pet that is treated as though it were someone's child. In the late seventies, the word pet was argued to be politically incorrect by animal-rights activists, since it implied human ownership of an animal, and the alternative phrase companion-animal was suggested. In the noughties, it seems, we've gone one step further and introduced a term which goes beyond the idea of an animal as a mere companion, elevating its status to that of a kind of surrogate child: the furkid. In short, Furkid is used by some animal lovers who feel that the word pet suggests the idea of owning something rather than describing the loving relationship that they have with their dog, cat, etc. Furbaby is another similar term for a baby pet that is like a human baby for its owner.
Furkid is an example of a compound noun which is a noun that is made by combining two other words (in this case the nouns fur + kid). This is the most common way of forming new words in English. Sometimes the compounds are written separately, sometimes they have a hyphen and sometimes they are joined into a single new word (weblog).