Cats were often mascots on navy ships during WWII. They kept the rodent population down and improved morale for the crew. 
taken from fb

Cat well cared for

American soldiers wounded during the Normandy landings are evacuated in an LCM landing craft; June 1944.


Taken to a hospital ship

A U.S. Navy destroyer (in background) lays a smoke screen during a Red Alert for air attack, off the Salerno, Italy invasion beaches in September 1943. Photographed from the port side bridge wing of USS Philadelphia (CL-41). Note manned and ready 20mm and 40mm guns on Philadelphia..