Wry neck is a postural disorder in which a bird loses control of the muscles that hold its head upright. The neck twists, and the head turns or tilts to one side. The clinical term is torticollis.
The posture shows where the damage sits, in the vestibular system or the brain tissue supporting it. It does not show what caused that damage, because nutritional deficiency, viral infection and bacterial encephalitis all produce the same picture. Each of those causes acts on the whole house rather than on one bird, which is why the investigation starts with the flock.
What causes wry neck in chickens
Vitamin E deficiency is the cause named most often in general guidance on the condition. It acts through encephalomalacia, also called crazy chick disease, which develops when diets are very low in vitamin E, when antioxidant levels are too low, or when the ration carries unstable unsaturated fat (Korver, 2023).
The strength of that link is routinely overstated. The classic sign of encephalomalacia is ataxia rather than a twisted neck (Korver, 2023). Dinev (2007) records torticollis as only rarely observed in vitamin E deficiency. On its own, a twisted neck is weak evidence for a vitamin E problem.
Wry neck in a commercial house is more often infectious. Newcastle disease, Marek’s disease, avian encephalomyelitis and listerial encephalitis all damage the central nervous system directly. Each is a flock problem with its own control route, so the useful next step is a diagnosis rather than a supplement.
There are two routes to a deficiency, and only one of them is the ration. A correctly formulated compound feed can still leave birds short, because an enteric infection limits what the gut takes up. Eimeria maxima coccidiosis reduced plasma alpha-tocopherol by 35% in mild cases and 73% in severe ones, at every dietary vitamin E level tested, through lipid malabsorption (Allen and Fetterer, 2002).
Those are also the diseases that depress growth, so the deficiency and the lost weight arrive together. Eimeria and necrotic enteritis challenges cut flock uniformity by roughly 2 to 4 percentage points in the trials collected by Choi et al. (2026).
Wry neck treatment and vitamin E dosage
Where vitamin E deficiency causes exudative diathesis or muscular dystrophy, the signs can be reversed if treatment starts early, and a single oral vitamin E dosage of 300 IU per bird usually produces remission (Korver, 2023). Where malabsorption rather than the ration is the cause, adding vitamin E to the feed does not reliably correct it (Allen and Fetterer, 2002).
Encephalomalacia, the form linked to nervous signs, responds less predictably. Whether a bird recovers depends on how much damage the cerebellum has already sustained (Korver, 2023).
Individual treatment is not a viable commercial route. Damaged cerebellar tissue does not regenerate, and a bird that cannot orient its head cannot compete at the feeder. Affected birds are culled. The correction that carries economic value is the one aimed at whatever is still acting on the rest of the flock, whether that is the ration or an infection.
Those birds are usually spotted during routine weighing, because catching and handling birds one at a time is one of the few routine tasks that puts a stockman in contact with individual birds.
What the rest of the flock shows
The affected bird will not recover, so the question worth asking is what the same event did to the birds still in the house.
Regmi et al. (2024) investigated Newcastle disease across ten broiler flocks totalling 9,840 birds. Torticollis appeared in two of the ten flocks. Inappetence and drowsiness appeared in all ten.
The pattern matters more than the totals. A flock that goes off feed stops gaining against the curve, and that deviation is visible whether or not any bird in it twists its neck.
The BAT2 Connect automatic poultry scale records average weight and coefficient of variation continuously, so a growth curve pulling away from standard becomes visible as it develops rather than at the next scheduled sample.
A deviation is easier to read against a baseline. Comparing this flock’s curve with previous crops on the same farm shows whether the loss is specific to this crop, which points at something that changed in the house this cycle, and holding those weight histories in one place makes that comparison possible.
Confirming recovery after the correction
Weekly sampling with the BAT1 manual poultry scale
is where affected birds are actually found. A platform reports flock averages and cannot single out one bird. Manual weighing puts every bird in the sample into a stockman’s hands, so posture, fleshing and physical condition are assessed at the moment the weight is recorded.
Manual sessions give a clean sample, because each weight belongs to a bird handled exactly once, while uninterrupted daily weight recording gives the continuity needed to confirm the curve has returned to standard.
Wry neck is a prompt to investigate, not a condition to treat. The bird tells you to look. The weight data tells you how far the problem has spread.
References
- Allen, P. C., & Fetterer, R. H. (2002). Interaction of dietary vitamin E with Eimeria maxima infections in chickens. Poultry Science, 81(1), 41-48. https://www.sciencedirect.com/science/article/pii/S0032579119435505
- Choi, J., Goo, D., Ko, H., Lee, J., & Kim, W. K. (2026). Factors affecting flock uniformity in broiler production: individual, environmental, and management characteristics. Animals, 16(2), 185. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12837223/
- Dinev, I. (2007). Vitamin E deficiency. In Diseases of Poultry: A Colour Atlas. Ceva Sante Animale. https://www.thepoultrysite.com/publications/diseases-of-poultry/218/vitamin-e-deficiency
- Korver, D. (2023). Vitamin deficiencies in poultry. MSD Veterinary Manual. https://www.msdvetmanual.com/poultry/nutrition-and-management-poultry/vitamin-deficiencies-in-poultry
- Regmi, S., Bhatta, R., Pal, P., Shrestha, A., Mató, T., Puri, B., & Paudel, S. (2024). Clinicopathological and molecular investigation of Newcastle disease outbreaks in vaccinated and non-vaccinated broiler chicken flocks in Nepal. Animals, 14(16), 2423. https://www.mdpi.com/2076-2615/14/16/2423