unwell hens

hi all, we have just inherited 20 hens , some of these are ex battery hens and some were hatched locally. the problem is a couple of the ex batts have a foul smelling white discharge coming from their vents, does any one know what this is and is it contagious to the others??
can it be treated or do i need to cull?
 the second problem is that quite a few of them have 'fluffy' feathers at the base of their backs just above the tails, i have been told that this might be a mite of some sort, any ideas would be gratefully accepted......

If this is vent gleet as suggested I found this after a quick google search.
As you have 20 or so birds you can easily make buckets of yoghurt at home to keep your costs down. Apple cider vinegar and molasses are all available at your local feed merchant and probably epsom salts to. Maybe a trip to a chemist might provide you with some of the other ideas mentioned.

http://ultimatefowl.atwiki.com/page/Vent%20Gleet

To make yoghurt. Easy piesie method.

Make sure everything is very very clean.

Bring a big pan of milk up to the boil (millions of little bubbles will do). Remove from the stove.

Whisk in 5 tablespoons of dried milk (I use Marvel) until well dissolved. This makes a nice thick yoghurt but if you don't use it your yoghurt will be fine, just a little thinner.

Allow to cool to a temperature that you can place a little finger in the milk and hold it there for 10 seconds without  feeling uncomfortable.

Whisk some probiotic (I use a small tub of Yo Valley Organic) yoghurt into the milk.

Place in a warm place, the back of an Aga or on a heated towel rail or on a pet warming pad for 3- 5 hours. I cover mine with an old woolly hat (cling film over the mixture to stop bits of dust falling in it).

Bingo you have  bucket of yoghurt!

Hope this helps.

Orchardlady.

PS I've been making yoghurt for me to eat every day for over two years now like this and haven't poisoned myself yet!

vent gleet is what i thought also (after looking it up) , i have been advised to cull sick ones to keep infection down as i saw one hen pecking at the discharge of another, how contagious is it?

Culling seems a bit harsh as a first measure, when with a little treatment they could be fine. Have you got somewhere you can quarantine the poorly birds so they don't get pecked? Something like a small house & run or a broody coop would be fine.

Also, if there is a sore area, spraying it with purple spray would prevent the other birds pecking it.