In regards to an animal shelter, why is it called "the pound?"?

Answer 1

No, it's not short for anything. In particular it is not FROM "impounded". The connection goes in exactly the opposite direction, That is, "impounded"--meaning 'to confine in as if in a pound' --comes from "pound" !!
http://www.thefreedictionary/impound

As for the word itself -- it more generally means an 'enclosure' or place of confinement, and is historically related to "pen".


See the following;
pound 3 Pronunciation (pound)
1. A public enclosure for the confinement of stray dogs or livestock.
2. A place in which impounded property is held until redeemed.
3. An enclosure in which animals or fish are trapped or kept.
4. A place of confinement for lawbreakers.

[Middle English, from Old English pund-, enclosure (as in pundfall, pen).]

http://www.thefreedictionary.com/pound


("Compound" by the way, comes from the Latin componere, 'to put together', and is historically unrelated to poud/impound.)

Answer 2

It is called a "pound" because the animals taken there are Impounded, like confiscated cars, ect.

It is a nick name that has become so common as to not--usually--be questioned why.

Answer 3

Because it is where the animals which are picked up are "impounded", hence, in short form, the pound.

Answer 4

Short for compound, just like the Kennedy's home.