guinea pig lump above genitals

Question
hi. i have a male  guinea pig that has had hard little lump on lower abdomen above his private part. over the past couple of days the lump has gotten bigger and the skin now appears a little red. when i lightly press on it, his urethra moves out. i am wondering if this may be some kind of bladder infection or obstruction? about 3weeks ago i found a piece of wood shaving sticking out of his urethra and we had to pull it out. since then, no shavings in cage at all!  in addition, he has been fighting (and i have been religiously doctoring) a sore infected footthat he had when we got him. maybe his lymph glands swollen?  he appears fine otherwise i am not sure what to do. thank you for your suggestions and taking time to help!  blessings, Donna  

Answer
He could possibly have an obstruction of the penis, or a stone could be lodged there, it is really hard to tell with out examining it. He will need to see a vet though, because whatever it is will need to be fixed, and he will most likely need antibiotics. It may also be a twisting of the penis in which the blood flow got cut off causing inflammation. Guinea Pigs can have swollen lymph glands near their cheeks, and cyst are very common in that area. Let meknow if you have any more questions.
Brittany