Rescued hen (update: or rooster?! please help in identifying) found in garbage coming home tomorrow

I witnessed the most horrible thing yesterday. I was walking my dog when I came across garbage men who stopped me to tell me they had found live animals in a garbage bin and that they were in their truck. Sure enough, there was a bag with dead chickens and a poor live hen lying on top of them. I took the hen to the vet yesterday and will bring her back home with me tomorrow morning. We will be keeping her in the house in a dog crate for a few weeks until she is better. I will know more tomorrow on her health but the vet recommended that I treat her for lice/fleas and worms. I already have 4 hens in my backyard but they won't have contact with this new hen for a few weeks.
This is my first time rescuing and treating a bird so any advice would be greatly appreciated. How long should I keep her inside for? What precautions should I take? (I know absolutely no contact with my other birds and change of clothes and everything).
Anything else I should be aware of?? I don't want to put my flock at risk of anything.

Thanks in advance

** update 12/05/16

I'm back from the vet's clinic and they are keeping the chicken for a few more days because as soon as I took a closer look, I believe the chicken is a rooster...I took some pictures so I could have some more input. The people at the vet's office weren't sure either as the vent area is pretty red and the technicians don't really know what to look for. The vet was on the road so couldn't take a good look at him. Here are some pictures, what do you think? the upright tail is what makes me doubt

That was nice of you
Most definitely practice good biosecurity and quarantine her (usually 30days).
Any idea what/why the other chickens were dead from?
You state that you will be bringing her home and crating her "until she is better". Does she seem injured, malnourished, sick?
There are several poultry diseases that are contagious, so you will want to observe her closely. Any signs of sneezing, discharge from eyes/nose, coughing, wheezing or any respiratory issues you will need to decide if it is worth the risk.

Post photos when you get her, would love to see her.

Quarantine:
https://www.backyardchickens.com/t/12751/urgent-reminder-please-quarantine-newly-acquired-birds

Mites/Lice:
http://www.the-chicken-chick.com/2012/08/poultry-lice-and-mites-identification.html
http://www.fresheggsdaily.com/2013/02/mites-how-to-prevent-them-and-treat.html
http://fresheggsdaily.com/2012/01/dust-bathing-beauties.html


Worming Info:
http://www.the-chicken-chick.com/2015/11/control-treatment-of-worms-in-chickens.html

Common Poultry Diseases:
http://edis.ifas.ufl.edu/ps044

Wyorp Rock said:

That was nice of you

Most definitely practice good biosecurity and quarantine her (usually 30days).
Any idea what/why the other chickens were dead from?
You state that you will be bringing her home and crating her "until she is better". Does she seem injured, malnourished, sick?
There are several poultry diseases that are contagious, so you will want to observe her closely. Any signs of sneezing, discharge from eyes/nose, coughing, wheezing or any respiratory issues you will need to decide if it is worth the risk.

Post photos when you get her, would love to see her.

Quarantine:
https://www.backyardchickens.com/t/12751/urgent-reminder-please-quarantine-newly-acquired-birds

Mites/Lice:
http://www.the-chicken-chick.com/2012/08/poultry-lice-and-mites-identification.html
http://www.fresheggsdaily.com/2013/02/mites-how-to-prevent-them-and-treat.html
http://fresheggsdaily.com/2012/01/dust-bathing-beauties.html


Worming Info:
http://www.the-chicken-chick.com/2015/11/control-treatment-of-worms-in-chickens.html

Common Poultry Diseases:
http://edis.ifas.ufl.edu/ps044

Click to expand...

Thanks for you help, I have posted some pictures above

That's a hen, a red sexlink hen, to be exact.

The chicken is very sweet.
It is missing some feathers in the neck area and on the back, so it's hard to tell by the feathers. Plus, there are no spurs. I'm so confused!

Thanks for your input!

She's a cute little thing.
Hopefully all will do well.