Be polite, and you'll get a polite reaction, but CALL:

 1) Louisiana Governor's office, (866-310-7617)

2) FEMA National Number:

The Honorable Michael Brown
Under Secretary of Homeland Security for Emergency Preparedness and Response
500 C St. S.W.
Washington, DC 20472
202-646-3900
202-646-3930 (fax)

Flood them with calls! Just explain politely that you're concerned about the people and animals of N.O. and other areas and urge/demand of them to let people evacuate with animals and let ALL volunteers who want to rescue people or animals in.

3. The New Orleans Mayor.  Flood his office with emails. Go to the following site:

http://www.cityofno.com/portal.aspx?portal=1&load=~/SystemModules/ContactUs.ascx&contacttype=message&contactid=207

4. Your Sentators and Representatives to Congress (use your resources and look up the numbers. Again, it's best to call!!)