Tim there used to be a product a product called Odor Mute that you could find at Nite Lite or Bill Boatman hunting supplies that would help. I used it years ago when I had my racoon dogs on dirt. Mine have been on concrete for years now. I spray the kennels with Clorox in a pump up sprayer and that helps sanitize and I don't really notice the smell at all this time of year. This rainy wet weather hasn't help your situation much. Slack Lime ( White Lime) helps too but I think it would be more for flies than smell.
I would be glad to come take another one or two off your hands too if that would help. lol
Roger
I would be glad to come take another one or two off your hands too if that would help. lol
Roger