My oldest granddaughter and her son have a mixed Collie/German Shephard puppy.  They both have started to have problems due to the poor air quality that is causing stuffy noses (even though she keeps a clean place and uses air fresheners).  The apartment still has a dog smell. Well, after using this purifier for about a week now, she says she has noticed a big difference in the quality of the air, they are no longer feeling stuffy, no dry eyes, no musky smell, no breathing difficulties. She is very pleased and so am I being a concerned Grandma!