Please see the picture, and many thanks in advance.
I'm not expecting a full vet diagnosis from you guys, but I'm hopeful that someone has experienced something similar to this! He's booked into the vet first thing on Wed morning as I doubt it's life threatening and my vet is really busy, but atm I'm worried.
It wasn't there when I was brushing him yesterday, wasn't there this morning but this afternoon there it is. It's possible that I just didn't see it this morning, but it definitely wasn't there yesterday.
Now I'm off to see if there are any weeds anywhere in the yard that I haven't found
Edited because I forgot the picture!