"The animals we are finding now are emaciated and sick and lonely, but we are still finding them alive," Wayne Pacelle, president of the Humane Society of the United States, told USA Today.
Searchers have also found the bodies of animals drowned by flood waters or starved to death because they had been locked in carriers or chained up by owners who thought they would only be gone a few days.
About 8,000 dogs and cats gathered up by rescuers have been sent to shelters in 27 states and to temporary shelters at two Louisiana prisons. About 50 animals are reunited with their owners every day.
The recovered animals are held for 48 hours at two large shelters in Louisiana and Mississippi, where they are photographed. The pictures have been posted on www.petfinder.com, a Web site paid for by the animal groups involved in the rescue effort.