George and Amal Clooney to the Rescue Dog

Turns out George and Amal Clooney are humanitarians and canine-itarians ... because they just added a rescue dog to their brood.

The couple adopted Millie the basset hound, who is now the sister of Louie the cocker.

Millie came from the San Gabriel Valley Humane Society. The shelter tells us they had no idea George and Amal were coming by Wednesday afternoon ... they apparently fell in love with the dog after seeing its photo online.

The couple brought Louie along to make sure the hound would be a good fit at home. The staff said there was instant chemistry between all so they went ahead with the adoption papers.

Millie was found outside a restaurant looking for food before getting dropped off at the shelter.

George and Amal ... they do life right.