Whose poop is this anyway...
If you've got more than one dog (or cat) at home, odds are good that you've been faced with the "whose poop is this?" question at some point. Right? Whether you're needing to know because someone is having diarrhea, or because one of them is pooping on your carpets, figuring out which pet is having "bowel problems" is always the first step to figuring out why.
Fortunately, there's a quick and easy trick to help you figure out whose is whose, and it involves something that you likely have in your home right now (or can very easily, and inexpensively, grab at the store)... crayons!
How to feed your dogs crayons (this trick can be used with cats, too)
Using a vegetable peeler, make small shavings of different colored crayons — a different color for each pet. Mix a small 
amount of these shavings (about 1/8 tsp) into a small amount of wet food for each pet. Then separate your pets while they each eat their "colorful little snack” (watch to ensure that nobody is eating another's color-this will mess up your experiment). Then just keep an eye out for abnormal poops, the color of crayon in the poop will tell you whose it is!
INSET PHOTO: This "funfetti"-like poop wasn't the result of someone getting this tip horribly wrong. It was actually the, rather colorful, "end result" of a dog that got into a whole box of crayons! The dog was fine, and the family was in no danger of accidentally stepping on this bomb in the yard!
So, crayons are actually just one of the safe, easy, and not-too-messy ways to help you determine which of your dogs is having diarrhea or pooping in your home. If you prefer, you can also use a small amount (5–10 drops, depending on your dog's size) of concentrated gel paste food colorings (sometimes called "icing colors"). Just be aware that if you use these concentrated food colorings, they may stain your carpets! Alternatively, you can also use a small amount (about 1/8-1/4 tsp, depending on your dog's size) of regular, everyday glitter (VIDEO: the Saint Louis Zoo uses glitter!).
One important note should you elect to use the gel paste food colorings... at this time we aren't aware of any brands that contain the sweetener xylitol, but they could be out there or could come on the market. Be sure to always read the label before using any gel food colorings for this trick with your pets. If you find gel paste that contains xylitol, please let us know and we'll add it to this list of over 700 products that contain xylitol. (In case you weren't aware... xylitol is VERY dangerous to dogs!)
Regardless of whether you use crayon shavings, gel food colorings, or glitter, you may have to do this for a few meals or a couple of days — depending on how frequently your pets "go" and how closely you're monitoring their stools. But these are all safe, sure-fire ways to help you figure out the "who," so that you can then focus on the "why."
Why your pet may be having 'bowel problems' or defecating where they're not supposed to
There are many reasons why a dog may be having diarrhea, or why they may be pooping on your floors.
Diarrhea can result from:
- Dietary indiscretion (i.e., eating, or being fed, things they shouldn't)
- Infectious causes (e.g., viral, bacterial, worms, and others)
- Hormonal conditions (e.g., hyperthyroidism, Addison's disease, and others)
- Inflammatory reasons (e.g., inflammatory bowel disease, pancreatitis)
- And a host of other reasons
Defecating in the wrong place can also have a variety of causes, including:
- Arthritis
- Nervous system problems (incl., Canine Cognitive Dysfunction in dogs)
- Stress
- And many others
Your vet truly is your best resource for working through the potential causes of your pet's diarrhea and/or inappropriate defecation. Don't make the (often incorrect) assumption that your pet is "doing it out of spite" or that it'll "pass" — doing so may just be prolonging your pet's discomfort.
