Here is some information about the Ancona (which is not just a spotted leghorn.)
The Ancona breed was developed in a city in Italy from which they take their name. They are nicely spotted white on black, with yellow skin, and lay white eggs.
Anconas were introduced into the APA Standard in 1898. Chicks are are striking black and white. They were once one of the prime egg-producing breeds in Europe. Active and busy, they are good foragers and said to be indifferent to climate.
According to American Livestock Breeds Conservancy, the Ancona is on the Threatened listing. This means there are fewer than 1,000 breeding birds in the United States, with seven or fewer primary breeding flocks, and globally endangered.
I was sorry to hear about your Ancona chick, ticks. We had an Ancona hen and she was a sweetie. It could be that the chick didn't have enough vitamin E. I know that a lack of Vit E can cause problems with development of the muscular and nervous systems. But that is just a guess, as chickens seem to have many problems and diseases that look like each other.
Keep an eye on the rest and if you see anything suspicious, isolate those chicks.
