Many animals other than humans have Ultraviolet capable vision including dogs - Page 1

http://io9.com/superpower-vision-lets-cats-and-dogs-see-in-ultraviolet-1525842007

The lens of the human eye blocks ultraviolet light, but in animals with UV-transparent lenses, ultraviolet light reaches the retina, which converts the light into nerve signals that travel to the brain where the visual system perceives them.

Even in animals whose retinas aren't very sensitive to UV light, some of the light is still absorbed. (In fact, humans who have had their eye lenses removed, such as in cataract surgery, without being replaced by ultraviolet-blocking lenses report being able to see in the ultraviolet). 

Nevertheless, ultraviolet vision does serve several purposes. Bees and other insects use it to see colors or patterns on plants that can direct them to nectar. Rodents use it to follow urine trails. And reindeer may use ultraviolet light to see polar bears, which, in visible light, blend in with the snow.

http://www.huffingtonpost.com/2014/02/19/cats-dogs-see-in-ultraviolet_n_4814708.html