I noticed our Orpington roo limping and acting lame a few days ago and at first thought it was a symptom of what has killed a couple of our flock the last few weeks (possible Marek's-necropsy pending from other birds). We quarantined him and today I took a closer look since he had not progressed with the symptoms like the others had. The roo has developed a large subcutaneous lump on the bottom of his foot (see pic). It looks to me like he may have a thorn or splinter that has caused the swelling. You can barely see in the photo a dark pimple at the head of the swelling that might be point of injury. I would probably perform a little surgery on myself it if it were my injury , but not sure how to proceed with the 12 lb roo to determine exactly what it is. The nearest vet that will look at our chickens is 2 hours away. Any thoughts and/or advice?