Touched lost dog!

This is probably really stupid, but just looking for some advice/opinions.

We found a lost dog in our yard this morning and I touched it while trying to see if it had a collar. It didn’t have one.

It looked relatively clean but I’m still concerned that ether myself or our toddler (who was running out to pet the dog before we even noticed) could have caught something.

I know chances are slim but anyone out there with more knowledge or advice would be welcome.

Note: DAS can’t collect them till tomorrow and RSPCA isn’t open till Tuesday due to it being a long weekend in my area.