My rat has a very large lump hanging from her neck

Question

It sprung up over night. It definitely wasn't there yesterday. It's about the size of her head. It's kind of squishy when I touch it. What could grow so large so fast?

Answer 1

it could also be swelling of the salivary glands which is commonly seen in rats that have SDA or corona virus. look for red discharge from the eyes and/or nose. also bulging eye/s can also indicate infection.