OK!
Nutritional Deficiencies
1. Protein (amino acid) deficiency..................reduced growth, rough feathering
2. Vitamin D deficiency.......................rickets, severe weakness in bones, soft pliable beaks and claws
3. Vitamin E Deficiency...................... uncoordinated gait, backward or downward twisting of neck and forced movements
4. Vitamin A Deficiency......................stuntiness (stoppage of growth), weakness, drowsiness and ruffled feathers
5. Vitamin K Deficiency......................hemmorages on breast, legs or wings
6. Thiamin (B1) deficiency........................................loss of weight, ruffled wings, weakness in legs, unsteady gait
7. Riboflavin( B2) deficiency.....................................good appetite but slow growth, dirarrea and toes curled inward when walking
8. Pantothenic Acid Deficiency.............................crusty sores in corners of mouth, eyelids stuck together, sloughing off of skin on legs and toes and broken feathers
9. Nicotinic Acid Deficiency (niacin).......................enlargement of hocks and bowing of legs, diarrea and poor feathering
10. Pyridoxine (vitamin B6).............................jerky movement, poor appetite, poor growth, convulsions
11. Biotin Deficiency...........................same as pantothenic acid deficiency symptoms
12. Folic Acid Deficiency...................... anemia, very poor feathering and slipped tendon
13.Vitamin B12 (Cobalamin) Deficiency...............................slipped tendon and slow growth
Those are nutritional disorders that can be mistaken for disease. Treatable.
Treatable diseases:
Infectious Bronchitis...common cold among fanciers... sulmet can be used to treat, Have bird in heated area (heat lamp), no medication is required and the birds usually recover on their own (sulmet does help in my opinion)
Aspergillosis... caused by mold, nasal and eye discharge....clean bedding thoroughly and isolate harmed birds.
Those are some things I can think at the moment. Most diseases are heavy culling if your flock has it but if you have sanitary conditions, they really shouldn't be an issue. Coryza is serious as well as other mycoplasmas because you really can't get them out of their symptoms.....I like to go through the possibilities before considering culling...considering the symptoms. Sometimes the common cold presents itself in odd ways too.