I found these all-natural, biodegradable dog bowls via Daily Kibble. Called Fresh Licks Eco-Disposable Bowls by Everybody Green, they are made from 100% bagrasse, which is the fibrous residue that remains after sugarcane stalks are crushed to extract their juices. These bowls are sustainable and great for bringing on trips or to the park, plus you can throw them away without the guilt.