My dog ate cat poop and litter. Is it dangerous? When to see vet?

Oh dear! It's very common for dogs to do this, unfortunately - most of them love cat poop, and will eat it any chance they get. The good news is, it rarely causes any problems apart from some mild stomach upset as long as he only ate a small amount.

If he ingested a large amount of cat litter, there is a chance that this could cause an obstruction in his intestines - this is unusual in my experience, but can happen in dogs who consume really large amounts. Signs of this problem would include repeated episodes of vomiting, not wanting to eat, and not having bowel movements. If you notice any of these issues over the next day or two, then I would recommend taking Marcellus to the vet right away to be checked. But as long as he is eating fine and acting normal, you shouldn't need to worry.