I think you've been given excellent advice. Just wanted to throw another thought your way...
I have a Cream Legbar hen who is about who is about 6 years old. Every so often she will develop a limp which proceeds to her sitting around a lot. She seems healthy in every other way, stills lays well spring, summer, goes broody often and is a very good and attentive mother. She is also the friendliest of my flock and loves to sit in my lap, be held, etc.
She still walks when she gets like this but similar to your hen, acts uncomfortable like an old lady with hip/leg problems. In my hours and hours of reading hear at BYC, I came across several mentions of legs problems being resolved sometimes by adding certain vitamins. Nutritional deficiencies can cause problems with walking in chickens and other animals as well as humans if they get bad enough. Several of the B vitamins, Vit E and selenium can be involved in nerve function.
So...to try to shorten this long post...here is what I do when I first notice symptoms...
1/2 Vitamin B Complex Capsule (all the B Vits.)
1 scoop Rooster Booster Vitamins with electrolytes
1 gallon water
Mix and shake, shake, shake!
I give this for 3 days or so then give just the rooster booster mixed with water till she becomes more active, usually the rest of the week. This is her only water and she will drink it readily. I make fresh each morning.
I also give her just her complete feed with a little scrambled egg on the side as a treat. Eggs are a good food for them if they are not consuming enough feed, just not too often. The feed is best!
No other treats.
I read if they have been having symptoms a long while treatment will take a bit longer and if they've limped a really long time sometimes it does not help as nerve damage sometimes can be permanent.
So far this has helped Dixie 3 times. Each time 6-8 months apart.
Just something for you to consider.
