I can report with authority that coyote and fox pee starts to turn into ammonia after a year. After two years it is ammonia, with a hint of coyote or fox. Just in case anyone was wondering, and I am wondering what other people's experience has been with pee longevity. My trapping was so minimal last year (it rained nonstop) that I did not use up even the old pee from 2017, let alone the fresh stuff I bought for the 2018 season. Now to see if ammonia with a hint of fox catches anything. Suggestions?

Buy different urine.

Ammonia odor is common in aged urine. if there wasn't a whiff of ammonia, I'd be worried. If it doesn't smell like sewage, it's fine.

I got some coyote urine this year that smelled bad to me. A trapper friend of mine said he thought it was good. He had some fox urine from last year that smelled right to me but he thought was bad. He gave me the fox urine and I used bout. I caught at sets with both. Still wonder if any were repelled by the coyote urine.

Buy some of Andy Weiser's pee...

I use it from year to year with no issues and just a faint odor.

The ammonia smell will dissipate. Freeze it in the off season or store in a dark , preferably cool place .

Thanks, Gentlemen. I knew you all would know. And maybe in my dotage I have become hard of smelling, in addition to hard of hearing, hard of seeing, and hard of feeling etc

Thank you, Paul. You would know better than most

Right on

I was wondering how well it would work if frozen, or even if it was still viable after freezing. Thanks for the info!