Celebrate National Pet Month with this collection of adorable pets that are as happy as they can be. From grinning guinea pigs to smiling cats, all of these pets are seriously cheery. The month of May is dedicated to sharing just how special animals are and the benefits of taking care of pets. Giving your favorite friend a cuddle lowers blood pressure and promotes good overall health — and shows your pet that you think he's special too.
Source: Flickr user glennsajan , Instagram user raiment , Flickr user zebarnabe , and Instagram user tofuthebritishshorthair 
How cute is this smiling kitty?
Check out this big grin!
This guinea pig is all smiles.
Hey there, happy dog!
Nothing better than a smiling froggy.
This cat's so happy to have a lap to sit on.
This pooch has lots to grin about.
This pup's ready for a great day!
Another happy cat.
This rat loves his friend.
Yup, that's one happy pup.