Why don’t the Dallas and Fort Worth Zoos have polar bears, giant and red pandas in their collections? Is our climate too warm?

There are lots of possible reasons. No zoo can hold every animal because no zoo has the necessary room.

Zoos work together in regional associations and between them they decide which animals will be in which zoos.

A zoo may not have a particular species because the zoo population is too small and even if a zoo would like a particular animal species in its collection there may be no individuals of that species available.

Another consideration is space. A zoo may not have the space to build an enclosure of the appropriate size to house a specific animal.

Zoos often accept animals in to their collection based on their previous experience. So let's say a zoo had no experience of caring for any ursid species it may decide that it does not want one in its collection.

You could contact the zoos to ask them their specific reasons. They may, of course, choose not to tell you their reason.

One zoo can't have everything!  I used to complain when there were no capybaras or rock hyraxes.  But that's just the way it is.  

i think its possible, ask the zoo there about it