There are actually so many causes of leg disease in chickens

1. Deficiency of vitamins or trace elements

(1) When vitamin B1 is deficient, the sick chicken has weak legs, cannot stand, lies prone, and holds its head tilted upward in a star-gazing posture.

(2) When vitamin B2 is deficient, the sick chicken has poor tibial development, swollen joints, curled claws, and hocks resting on the ground. Some have legs splayed apart, or one leg forward and one leg backward, similar to the symptoms of Marek's disease.

(3) When calcium, phosphorus, and vitamin D3 are deficient or the calcium-to-phosphorus ratio is imbalanced, cartilage and osteoporosis occur, with thin and hollow bone walls and a honeycomb-like structure inside the bone, the keel bone bends, the ribs become deformed, and the joints swell. The sick chicken lies prone or on its side and cannot stand or walk.

(4) When manganese, selenium, zinc, and vitamin E are deficient, the sick chicken has short and thick leg bones, swollen hock joints, and in severe cases the leg bones become abnormally bent, the gastrocnemius muscle becomes displaced, and the legs extend outward, making the chicken unable to stand or walk.

2. Infectious diseases

(1) Viral arthritis: swollen and darkened hock joints, with clear, milky, or blood-like secretions. In prolonged cases, there is more fibrous tissue between the tendons, and the secretions become thicker.

(2) Marek's disease: swelling of the sciatic nerve, leg paralysis, and inability to stand. In most cases one leg is affected, forming a split stance with one leg forward and one leg backward.

(3) Adenovirus infection: chicks infected with adenovirus have long-term diarrhea. When the absorption of vitamins D and E and calcium and phosphorus is impaired, the sick chicken has poor skeletal development, osteoporosis, separation of the two ends of the long bones, and bone rupture and necrosis, and cannot stand or walk.

(4) Mycotoxin poisoning: mostly occurs in the moldy rainy season, caused by mold infection and poisoning from moldy feed or litter. The sick chicken develops enteritis and diarrhea, which affects the chicken's absorption of vitamins A, D, E, and K as well as calcium and phosphorus, hindering bone development and causing weakness and lack of strength in the legs.

(5) Mycoplasma synoviae infection: mycoplasma infection is often accompanied by difficulty breathing, swollen hock joints, and cheese-like secretions inside the joint capsule. In severe cases, the sick chicken develops lameness.

(6) Staphylococcus infection: because of beak trimming, comb trimming, or sharp hard objects in the exercise yard or chicken coop piercing the skin, or unclean drinking water leading to Staphylococcus infection, arthritis, synovitis, and toe cysts often occur, with lameness.

(7) Chronic chicken cholera: paralysis of one leg or both legs, unable to stand.

(8) Fowl cholera: in chronic cases, the joints swell and lameness occurs.

3. Other diseases

(1) Drug poisoning: poisoning by furazolidone, furacilin, olaquindox, sulfonamides, and the like causes leg paralysis, movement incoordination, and inability to stand in chickens.

(2) Feed poisoning: poisoning by rapeseed cake or cottonseed cake causes weakness, paralysis, and palsy in both legs.

(3) Gout: in leg-type gout in chickens, the tarsal joints swell, there is lime-like material in the joint capsule, and the chicken shows weak legs and lameness.

(4) Rheumatoid arthritis: chickens kept for a long time on dark, damp ground develop rheumatoid arthritis and become paralyzed.

4. General prevention and control measures

(1) Keep the chicken house clean and hygienic, @#@230@#@ the density should be moderate, and regularly spray-disinfect with 0.3% peracetic acid.

(2) Use complete compound feed to ensure the feed meets the chickens' needs for vitamins and trace elements, and the calcium-to-phosphorus ratio should be appropriate.

(3) When using drugs to prevent and treat diseases, the dosage must be accurate, and when mixing with feed for feeding, it must be thoroughly and evenly stirred.

(4) Do not use moldy or spoiled feed; cottonseed cake and rapeseed cake must be detoxified before feeding.

(5) If abnormal legs are found in chickens, in addition to taking comprehensive prevention and control measures, the cause should be identified and symptomatic treatment should be carried out.