Terramycin- Dosage/sickness question

[mothersin2ition]

I have a pullet who over the last week started sleeping under the coop at night instead of going inside, her comb is shriveled and whitish and she has runny poop that is all over her rear end. I don't notice any sneezing or coughing, and she's still eating/drinking, but she is staying away from the rest of the flock and generally just not acting the same as she was. I went to the feed store and they gave me Terramycin- is this what she needs? I love my local feed store people, but the lady I talked to doesnt have alot of experience with poultry and she's given me misleading advice on several occasions.
So do I give my girl this, and if so, how much? How much should I put in a one-gallon waterer? It says 200-400mg per gallon and unfortunately, I have no idea what that converts to for like tablespoon/cup

I have her in a "sick coop" by herself so I dont have to medicate the other girls. The meds say not to give to any chickens that are laying eggs for human consumption so I dont want to medicate them unless I need to.

Any advice??

 

[PeeperKeeper]

If it is the powdered form it will be 2 tsp / 1 gallon of water.
You need to isolate this little hen. Make sure she is drinking, if not then "drench" her. Pop her little beak open and squirt the solution/water mix into her. Electrolytes and vitamins would also help. Pedialyte or gatorade and Polyvisol baby vitamins. Don't get the ones with Iron because they don't have the B vits needed when one is having these kinds of problems. Use a dropper full for the first dose of vits. then 2-3 times for that week until she feels up to eating and running round again.
I personally do not like the terramycin for internal use. There is a product called Corid for cocsidiosis.
Just remember...Chicks/chickens dehydrate quickly.
http://www.welphatchery.com/poultry_health.asp
Try this site for some suggestions.