Nothing ruins a kiss from your dog like feces breath. If your pooch's favorite snack is someone else's waste, it's up to you to help her kick the habit. Flavoring agents are unpredictable as deterrents, so the best you can do is modify the behavior, not the taste.
If you have a cat and a dog, your poop-thieving pooch probably gets most of her illicit snacks from the litter box. The best way to prevent her from digging for buried treasure is to keep her away from the litter box altogether. If you have a small dog, this can be as simple as putting the litter box up and out of her reach. As for bigger dogs, keep the litter box in a room that the cat has access to but the dog does not.
A little diligence is one of the easiest ways to prevent your dog from chowing down on any unapproved ground snacks. If you allow your dog free reign in the backyard, make sure that you clean up any droppings she leaves behind -- otherwise, she may snack on them next time. Same goes for the cat litter box. If you can't find a way to physically prevent your dog from getting to the cat litter box, simply check and empty it once or twice a day.
Watch Her Carefully
There aren't many circumstances under which your dog is around feces and she isn't supervised. For example, when you take your dog for a walk, she's likely to find a pile here and there that a negligent owner left behind. Stopping her from digging in is as simple as saying the word, literally. Make sure your dog is trained to obey a simple "no" command, and pay attention to what she's doing when you take her for a stroll.
Improve Her Diet
Your dog may be eating feces as a kind of dietary supplement. For example, if your dog is eating a lower-quality dog food, her body isn't absorbing a lot of its ingredients -- meaning it tastes remarkably the same both before and after she eats and excretes it. Upgrading your dog's food can help prevent this, as it provides her body with more nutrients and is more heavily processed before it comes back out. Providing warm wet food for your dog can also help, as it mimics the texture and temperature of fresh feces.