Are There Dangers In Smelling Red Fox Urine?

Recently, while trailing in Algonquin Park with the Earth Tracks Wildlife Tracking Apprenticeship some of us bent down on different occasions to smell Algonquin Wolf, Red Fox, and River Otter scent marks, which were usually small deposits of urine placed in a prominent spot along the animal’s trail. When we got back to the Wildlife Research Station which was our home base for the weekend, we got to talking about safety around sniffing animal urine when trailing.
Personally, I have smelled animal urine literally hundreds of times. Nearly every time I see a urine deposit on an animal trail, aside from Human (Homo sapiens) and other domestic animals, I get down and sniff. But the questions got me reflecting; When tracking or trailing an animal, are there dangers in smelling animal urine?