Pet odor can be simply that Buffy hasn’t had her bath in a couple of months.  

Granted the smell can be terrible but this clearly is just plain old pet odor.

Buffy’s bedding can develop quite a nasty odor if not washed regularly.

Pet urine on the other hand is that strong odor that is the result of your cat or dog urinating repeatedly on your carpeting and upholstery.

Buffy’s bedding can easily be washed in your favorite detergent.

Pet urine on the other hand requires a competent cleaning agent to successfully remove that strong urine odor.