I have 2 sick chickens, First one born 23-10-16 so 3 months old. Has been sick for almost 2 weeks. Started as one leg not working, then it was back behind it, now one leg forward one back (like the splits) and can't walk. It lays on the ground and flaps. Still eating and drinking as we keep putting food in front of her but you can feel her breastbone if you pick her up. Have checked her all over and cannot find any injuries, mites, lumps, etc. She was a mixed pen egg but looks like a small black Aracuna, or possible smooth frizzle, has the green through her feathers. Was hatched by me from bought eggs, raised on Medicated chick started till 5 weeks, then pullet medicated grower. Now has access to Mi-Feed layer mash, and layer pellets. Also all chickens in Brooder have Avian vitamins in their water until moved outside. All chickens free range during the day, have plenty of fresh home grown veggies eg silverbeet, corn, watermelon, peas, and also scraps. They also get a bowl of mill run in the afternoons mixed with water to make a mash (they kept stealing it from the cows so now get their own while they are out free ranging). Bedding in chook house in a concrete floor in back half, dirt in front half. Roosting perches, and nesting boxes with straw. They have 6 water containers all changed twice daily. We live on 40 acres outside Brisbane, Qld, Australia, and it has been very hot the last 2 weeks. She was hatched along with Guinea Fowl and Ducks, all share the chicken coop (huge coop) and no others sick. I did purchased 7 Aracuna cross laying chickens on 15th Dec 16. Had them in the back half of the chook pen for 1 week separated now all together. Sick bird no 2. I have my brooder over under my verandah that all hatchies go into. Current has 4 larger chickens, 4 quails and 6 babies in it. This morning I went to feed and water them and my oldest bird born 20th December is doing exactly what the one outside is doing. Right leg back, wonky on feet and just laying down. This was a different batch of eggs I purchased. This bird looks to be a Naked neck cross frizzle. Sex unknown at this stage. Was perfectly fine yesterday. Brooder in made from Marine ply. 1200 x 2400, half indoor half outdoor. Indoor has heat light. Outdoor has solid lid but mesh walls. Bedding is the wood shavings animal bedding. Eating Medicated chick starter, vitamin drops in water every day. They get greens, silverbeet leaves home grown every afternoon. Chook pen and brooder are probably 150m from each other. Any help appreciated.