Crop sample from necropsy of a female budgerigar 2,5years old.
I'm thinking M.ornithogaster. Did send a fecal sample and got negative result, but guessing that is because of intermittent shedding.
The owner has one budgie left that has been with this one.
Should I start treating the other budgie?
Looks like Macrorhabdus ornithogaster to me too. You should treat it. If it is a single bird 10-14 days will usually be sufficient. If it is a flock 21 days as some birds may not drink the medicated water and rather eat the droppings of other birds when they get thirsty (observation from my own flock when treating them). For treatment I recommend Amphotericin B, either Megabac S or Fungizone tablets.