You could call your state NPINP and ask them about testing. You also can ask the state vet what they would recommend. The third suggestion which is more expensive would be to call a national lab such as Zooloxix in CA, and have them send you swabs to test a sick bird with symptoms. Those swabs...
Hopefully, it is not something like mycoplasma (MG.) NPIP basically tests for pullorum, fowl typhoid, although they may or may not possibly test for avian influenza, MG and others. That probably depends on what they ask to test for. Your breeder might have something verified to show you about...
Are they getting pecked or bullied into running into the fence wire they are housed in? Can you see any bubbles in one eye on the swollen side? With the dark skin it looks like injuries on fencing, but a swollen face can also be due to a respiratory disease such as MG, or sting. MG can pass...