I'm sorry if this has been suggested before but I notice some people (including myself) want pets with a specific 'born' date for several reasons. How difficult would it be to create this search field for the adoption center? Is it even doable?

Yes it's possible It's just the matter of making user interface with the code for the search. I think a few drop down boxes would do the trick, although a calender would be more friendly.

I agree the current way of searching each pet is quite tedious.