My dog won't eat

Hello Everyone! I'm new here, my little aussie Rustic was outside with me yesterday and I heard him yelp and couldn't find anything wrong with him and then this morning he wouldn't eat his breakfast, or take treats and no supper! ( not like him at all) he acts fine otherwise, runs with my other two, drinks water, tried to eat grass as usual. I checked his teeth, gums, tongue all I see is one little lump on his bottom lip, was wondering if he could have been stung by a wasp, ( they were flying around me yesterday)? Any ideas?

Hello Ang and welcome
How is Rustic now, has he eaten anything yet.

All other things being well the lump could be an indication of a sting or bite. A little late to suggest it now but some ice in a cloth held against the lump for a few moments might have helped.

I would see how it goes, Rustic should be over the sting/bite in a matter of hours if not I would have a vet check to make sure there isn't a thorn causing the lump or some other problem going on.

no he still hasn't eat'in, no treats , no frozen yogurt in kong before bedtime, and no breakfast this morning, so I took a syringe with yogurt/blueberries (in blender) so he would have something in his belly! I still don't see anything in his mouth! Thanks anyways!

Is he toileting OK? He could have an upset tum.

If he's still not eating, a chat with the vet is in order.