>>23691
Definitely odd, could have been something in his diet being outside and eating weird stuff. Just a ton of fatty stuff.
Dogs also have scent glass that gives their butts a unique smell (this is why dogs sniff each other’s rears). Maybe his were overactive.
And my final idea: alol assholes have natural lubrication. It helps with passing waste. But sometimes assholes secrete this lubricant when not passing stuff. Some gay men don’t even need spit for a full on anal session.
When I was younger we had a German Shepherd. When I was home all alone he’d begrudgingly let me touch his tailhole. After some exploration of his outer anus with my finger he’d naturally lubricant his own back door. He’d usually had enough by the time this happened. But on rare occasions I could finger fuck his asshole. His insides were another world of warm and tight, melting my finger within him.
Zoophilia goes way back, and lubes weren’t really a thing back in the day. I know it’s a wild guess, but I think man’s best friend may have evolved ever so slightly to survive anal poundings a bit better. Not that lube isn’t necessary for tailhole, but that dogs secrete more natural lube.
Back to the black lab at hand, perhaps there’s someone else out in the neighborhood with similar interests to you. This wandering pooch is accustomed to what humans like you want, and waters in anticipation.