Answer:

There are a variety of treatments for this condition.

Scaly Leg is that roughened condition of the legs caused by a minute parasite burrowing beneath the scales, forcing them out from the leg by an accumulation of a white, crusty substance beneath them.

The color of the leg is destroyed and in cases of long standing, the legs and scales are entirely covered with the growth.

Here is an old-school remedy:

A mixture of equal parts of lard and common kerosene or coal oil should be applied to the legs daily until all the accumulated crusty formation has been removed.
Then apply carbolated vaseline once every two or three days till the new scales begin to grow.

Here are some new-school approaches:

1) A vet said:

Use an injectible ivermectin for cattle. He thinks that you should try to give one drop orally per 5 pounds of bird. Since I have Seramas, he told me to dilute the ivermectin. He said that I should repeat this in 2-3 weeks and maybe give it to one bird 1st to make sure I'm not overdosing  them

2) Using Ivermectin (Ivomec) for just scaly leg mites is like using a sledge hammer to kill a fly. Ivermectin is a potent de-wormer. It also kills Northern Fowl mites and chicken lice as well as scaly leg mites. If you need to do de-worm and de-louse, then Ivermectin is a good choice-- here's a website

http://shilala.homestead.com/ivomec.html

Be very careful not to get any of the Ivermectin on the vent of your bird as it can cause death.

Campho-phenique put on with an eye-dropper getting under the scales and repeat in a week or as necessary works wonders for scaly leg mites.

3) Try WD-40 spray/smear it on their legs. My neighbor used it-put it on once and two weeks later when she went to do it again to catch any new hatch-lings their legs were looking almost normal-they had had a very bad case too.

4)The best thing to use to clear up mites etc is called-prozap insectrin dust. and believe me it works wonders and its like 5.00-6.00 a 2# shaker can and 1# does 100 chickens.

5) I use baby oil and coat the legs using a small paint brush! It takes a few weeks to really see that it is cleared up...works for me and is readily available...

6) The ONLY thing that worked for me was Red Cote, the active ingredient is Scarlet Oil. It smells nice but looks like they're hemorrhaging- there's a reason it's called Red Cote!

The best wormer I've used is Eprinex, it's topical and does work for almost every kind of parasite imaginable. With a dosage of 1/2 cc per large fowl a bottle lasts a long time. I didn't see a difference with scaly leg mites though, maybe I was just too impatient but the Red Cote seamed to work within days.

7) Usually daily coats in Vaseline does the job in a few weeks. It does take times for the scales to come back normal though.