Biobased cat litters made of a variety of materials are currently sold internationally, as many cat owners are concerned with disposal problems encountered with traditional inorganic clay-based litters as well as the fact that cats might harm themselves by ingesting these litters or by inhaling clay dust. Several commercially-available cat litters contain Eastern red cedar (ERC), Juniperus virginiana L., wood fibers as a major constituent. ERC fibers contain sesquiterpenes that have been shown to be toxic to fleas and ticks. The objective of this research was to determine if ERC fibers combined with ERC biochar at 1, 5 and 10 % (w/w%) would produce an odor-reducing, biodegradable cat litter. Sieving ERC fibers and adding mineral oil significantly reduced release of dust (< 10 μm) particles. Addition of juniper biochar reduced headspace levels of 3-mercapto-3-methylbutan-1-ol (MMB), the major offensive cat urine volatile odor compound. Addition of 250 ppm copper sulfate to the litter formulations did not result in a significant decrease in headspace MMB compared to the litter containing 10 % ERC biochar. All litter formulations had high hydration capacities (the ability to absorb liquids), and with the addition of guar gum as a clumping agent the litter formulation containing 10 % ERC biochar had the most desirable physical and chemical properties for development as a commercial cat litter.