Welcome To BYC
I'm sorry about your hen.
Do you have photos of the foundling and her poop?
Do you still have the body of your hen that died? If you do, you can refrigerate it and send it to your state lab for analysis, this will give you the most info about what happened. If not possible, and you still have the carcass, feel like you can, open it up and look at the internals - heart, liver, reproductive system, etc. Sometimes you can tell what was going on. IF you do that, take photos, we'll try to help you with what you see. It may not be possible if the body has started to deteriorate.
It's nice that you took the poor hen in. It is a good idea anytime you bring in newbies to keep them housed separately for observation.
Possible she has something can affect your flock, some birds can be carriers of illnesses that can be transmitted through dust/dander, bodily fluids, etc. and not show any signs of illness.
For an illness to affect another hen in 3 days, just some common sense says you'd see some type of symptoms from the one that died (and very likely the new one too). Symptoms of certain respiratory diseases can appear that quickly, but again, you'd see symptoms. A disease like Marek's would take weeks. If it were something that moved that quickly and deadly, you'd have other birds that are ill with symptoms.
I lean toward this is coincidence since the hen was around 4, she had troubles with bumblefoot. You don't mention if she was actively laying or not. At 4 a hen can begin to have some problems, cancer, liver/heart dysfunction, etc. It's the pits, but sometimes they just die and unless there's further investigation it can be a guessing game.
Worming the newbie may be a good idea or getting a fecal float to see if your other hens need deworming would be good to do.
The existing birds would not be showing symptoms of worms in this short period of time IF the newbie has any. They would have to ingest her poop, then that poop would have to have worm eggs, then it would take a few weeks for anything to really get going with worms. So, you're looking at ehhh, at least a month.
You can find your lab here:
https://www.metzerfarms.com/poultry-labs.html
I'm sorry about your hen.
Do you have photos of the foundling and her poop?
Do you still have the body of your hen that died? If you do, you can refrigerate it and send it to your state lab for analysis, this will give you the most info about what happened. If not possible, and you still have the carcass, feel like you can, open it up and look at the internals - heart, liver, reproductive system, etc. Sometimes you can tell what was going on. IF you do that, take photos, we'll try to help you with what you see. It may not be possible if the body has started to deteriorate.
It's nice that you took the poor hen in. It is a good idea anytime you bring in newbies to keep them housed separately for observation.
Possible she has something can affect your flock, some birds can be carriers of illnesses that can be transmitted through dust/dander, bodily fluids, etc. and not show any signs of illness.
For an illness to affect another hen in 3 days, just some common sense says you'd see some type of symptoms from the one that died (and very likely the new one too). Symptoms of certain respiratory diseases can appear that quickly, but again, you'd see symptoms. A disease like Marek's would take weeks. If it were something that moved that quickly and deadly, you'd have other birds that are ill with symptoms.
I lean toward this is coincidence since the hen was around 4, she had troubles with bumblefoot. You don't mention if she was actively laying or not. At 4 a hen can begin to have some problems, cancer, liver/heart dysfunction, etc. It's the pits, but sometimes they just die and unless there's further investigation it can be a guessing game.
Worming the newbie may be a good idea or getting a fecal float to see if your other hens need deworming would be good to do.
The existing birds would not be showing symptoms of worms in this short period of time IF the newbie has any. They would have to ingest her poop, then that poop would have to have worm eggs, then it would take a few weeks for anything to really get going with worms. So, you're looking at ehhh, at least a month.
You can find your lab here:
https://www.metzerfarms.com/poultry-labs.html