It’s official. Birmingham, Alabama, is the cat-friendliest city in the U.S. A website that rates pet products, PetListed.com, made the finding when it evaluated the 100 most populous cities according to four criteria: the availability of cat-friendly housing; the number of veterinary practices certified by the American Association of Feline Practitioners (AAFP); the preponderance of local animal shelters and animal welfare groups; and the number of pet stores selling cat products.