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Avian Goiter

Other Names: Thyroid Hyperplasia, Dysplasia

Avian goiter is an abnormal enlargement of the chicken's thyroid gland, which is located in the neck. It's presence does not necessarily mean that the thyroid gland is malfunctioning, but rather indicative that there is a condition present that is causing the thyroid to grow abnormally. There are several conditions associated with the development of goiter, such as:
  • Dietary iodine deficiency The thyroid gland uses iodine to produce thyroid hormones. When there is not enough iodine in the blood, it causes the brain to signal the thyroid glands resulting in a proliferation of follicular epithelial cells, eventually resulting in enlargement of thyroid gland.
  • Exposure to toxins: When chickens are exposed to high levels of organosphosphates or chlorinated biphenols it can cause an enlargement and hperplasia of the glands.
  • Genetic defects
  • Trauma
  • Septicemic diseases: When they are associated with an acute onset it can affect the thyroid glands and causes inflammation and hyperplasia.
In chickens, avian goiter is most often caused by excessive eating of goitrogenic agents, such as kale, broccoli, turnips, cabbage, flax rapeseed, and soybeans.

Clinical Signs

Enlarged masses along the neck
Easily develop infections
Skin and feather abnormalities
Decreased hatchability
Increased embryo mortality
Sudden death
Weight loss
Difficulty swallowing
Crop blockage
Loss of voice
Respiratory abnormalities


  • History
  • Clinical signs
  • Diet analysis
  • Blood tests
  • Necropsy


Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
Supplemental iodineProvide one drop of dilute Lugol's solution in 1 oz. of fresh drinking water, x 1 weekG Butcher et al., 2015



Supplement iodine in diet of living in an iodine deficient area or feeding goitrogenic substances to chickens - Provide one drop of dilute Lugol's solution in 1 oz. of fresh drinking water, x 1 week

Scientific References

Good Overviews

Risk Factors

  • Eating an iodine deficient diet
  • Eating large quantities of goitrogenic agents such as soybeans, rapeseed, cabbage, turnips, broccoli, cabbage, and flax