I use cedar shavings for bedding. Triflexis for use on dogs. Stuff is pricey so I get the largest dose and cut it into size appropriate for weigh. I hope the medicine is spread evenly. It seems to work.
Where ever there are animals there will be fleas. Allegedly Ivermectin controls fleas as well.
If you shoot a rabbit hang it up in a tree after you dress it out, fleas in the ears, you'll watch them on the rabbit. Done hunting go get the rabbit should be flea free. JMO