CatDog
Sources/References
CatDog
Inside 'CatDog' (Washington Post - 2000)Interview with Peter Hannan, creator of CatDogHow does CatDog go to the bathroom? No one knows, myself included. What I used to say, because I was worried that kids might think CatDog would explode if they didn't go to the bathroom, was that they definitely do go to the bathroom, but no one knows how. Nobody ever asks how Mickey Mouse goes to the bathroom, so we don't really need to know.
Without A Doubt, ‘Cat Dog’ Is The Weirdest Show You Watched as A Kid (Bustle - 2017)How Does CatDog go to the Bathroom? (NickRewind / YouTube - 2016)Proposes the three theories discussed in the video
Animal Poop
7 Animals to Identify by Their Characteristic Poop (Interesting Engineering - 2020)Human Demodex Mite: The Versatile Mite of Dermatological Importance (National Library Of Medicine - 2014)These Face Mites Really Grow on You (Deep Look / YouTube - 2019)
Ostomy Pouches
Caring for Your Wet Colostomy (Memorial Sloan Kettering Cancer Center - 2019)This form of colostomy has two parts of the stoma, one for urine and one for fecal matter.
What Is a Colostomy/Ileostomy? (facs.org - 2016)Pouches can be used for urine and fecal matter. So this would weaken the theory of having a pouch while Dog can still pee volentarily, although it is possible to have urine and fecal matter emerge from different stomas.Pouches are also designed to capture and ventilate gas, which would mean if CatDog had such a thing in place, it’s possible Dog couldn't have farted in the way he does in the show.
A Guide To Ostomy Bags (Ostomy Diaries / YouTube - 2019)What is an Ileostomy? (Animated IBD Patient / YouTube - 2012)Highlights Ileostomy and Colostomy are not the same as it involves different areas of the digestive tract.So if CatDog had such a thing in place, presuming they have a colon as stated, they would hypothetically have a colostomy.
What is a Colostomy? (Salts Healthcare / YouTube - 2014)What the heck is a stoma? (Hannah Witton / YouTube - 2018)