Can cat waste be composted the same as dog waste? For the most part, yes. The big difference is that dog waste is mostly collected in plastic pick-up bags while cat waste is comingled with litter. Both of these co-mingled materials complicate the process. But the problem is easily solved for cat guardians who use organic litter made of grains, paper or wood pellets. This material can be composted right along with the poop.
When removing used litter, you’ll find that the litter will exceed the amount of poop by far. This imbalance disrupts the carbon-to-nitrogen balance needed for efficient composting. Adding food scraps, grass or other “green” materials will help to get the C/N ratio in sync. Otherwise you’ll need to find a sustainable way to deal with the excess surplus litter minus the poop. In that case it would be efficient to collect the poop separate from the used litter. Community composting facilities may or may not accept cat/dog waste as part of residential organics green bin programs.
Vermicomposting (transformation using worms) and a bokashi (fermenting) system also work with cat poop, although the processes are more complicated and require research and experimentation. If you sprinkle some dry bokashi bran in your cat tray now and then, it will help absorb odor and speed up any subsequent breakdown process. Bokashi bran can be purchased online or you can whip up a batch yourself: How to make it; how to dry it.
Cat waste might contain the parasite Toxoplasma gondii, which can cause toxoplasmosis—a disease that is especially dangerous for pregnant women and people with a weakened immune system. Because T. gondii can be spread in soil, take all the precautions suggested for composting dog waste and don’t use the finished compost on edible crops.
Because cat waste can easily infect water mammals, flushing cat poop, sending it to water treatment facilities or degrading it using an in-ground septic system are not recommended. Like composting facilities, biodigestion/AD plants may or may not accept cat/dog waste as part of residential organics green bin program.
More helpful information:
What’s the Greenest Way to Dispose of Cat Litter?
Clay-Free Cat Litter for Pet Sustainability
Got Cats? Get Worms! (vermicomposting cat waste)