OK - My logical head is telling me it's a lump from his injections last week
My illogical-panic-ridden-paranoid head is telling me there's something wrong!
The lump is definately in the vicinity of where he had his jabs and microchip...
...however, it's only been in the past two days that it's swollen into a lump - before then (straight after injections/microchip - Last Tuesday) it felt a little "gristley" - but not lumpy.
Do I take him to the vets?