I might be barking up the wrong tree here!! A long shot too.... But could it be Kanker???? We were sold White doves, who had Kanker but looked healthy only to go down hill super fast in dahs some hours. Luckily we quarantine, it was heart wrenching, excessive drinking unbelievable amounts, watery poop, so so wet! Loss of appetite. We lost a hen after a week, was on treatment like the others but just didn't respond. It's also transmitted through drinking water. What the lady didn't tell us, as she got them out of a flight, is that her birds are free flying, and said they were all treated. One she said had been attacked by a hawk and suffered brain damage, tests confirmed PmV.... When I told her she told me not believe everything vets say as they lie, and that all her birds were healthy, but had been locked down due to hawk attacks!!! And then messaged me to say her giant rabbit who lived with her doves had died, but said it had got to poison!!!
This lady claims to be working with the RSPCA for over 20 years, but selling sick birds. She sold me three chicks at the same time, one of hick was a pekin, that died 3 days later, the seramas are fine and both grown now. When I informed her of the chick passing she told me not to worry, that it was nothing I'd done wrong, that 3 had died at her's the day before!!! This lady continues to sell. It infuriates me. I hate people who claim to do it for the love if the animal and not for profit selling sick animals to unsuspecting buyers. It's heart wrenching and so stressful.
I feel so bad for you.
The thought of Kanker might be a long shot, but sounds very similar to what these doves went through. Pleased to say apart from Patrick ( PMV ) sufferer and the hen, the rest made a full recovery, after quarantine to rule out more PMV infected birds, all healthy happy birds now.