Is this a new vet ? Sorry if I missed it. I can tell you that even reptile vets that work with zoos misdiagnose bearded dragon problems so I wouldn't put much stock in credentials. I've seen several " highly recommended vets " that could not even sex an adult dragon, both times females, 1 actually laid eggs the day after the vet told the owner the dragon was not gravid [ pregnant ]. Anyway, there have been MANY cases here where beardies were diagnosed with fatty liver, I never remember internal bleeding that caused swollen beard or lump to appear on the head. I'd say no the shot but you'll have to decide for yourself. Has your dragon poo'd lately, if so was there blood in it ?