What do I know about goiter? My knowledge could be summed up by recollections of a Seinfeld episode in which the main characters decide to volunteer helping the elderly. Elaine is paired up with a woman with a repulsive goiter on her neck. I vaguely knew they had something to do with the thyroid, but was surprised to find out chickens can get them too. Nothing should surprise me about chickens because they are susceptible to all kinds of conditions that affect us, and a whole lot more that don’t.
The summer I turned 17 I picked up a virus that affected my thyroid. I was working in northern Ontario in the Junior Forest Ranger program and didn’t have access to a doctor for a couple of months. What I remember about that time is I was the only participant that managed to eat the three meals and three snacks provided each day and still lose a substantial amount of weight. That’s because the thyroid glands regulate metabolism, digestive function and growth (as well as heart and muscle function; brain development and bone growth).
Avian Goiter is an abnormal enlargement of the chicken’s thyroid, which are hormone glands located in the neck. It’s presence doesn’t necessarily mean that they’re not working, but indicate there is an underlying condition that is causing abnormal growth.
- Dietary iodine deficiency: The thyroid glands uses iodine to produce hormones. When there isn’t enough iodine in the blood, the brain signals the thyroid, triggering an increase of epithelial cells, eventually resulting in enlargement of thyroid glands.
- Exposure to toxins: high levels of organophosphates (i.e. insecticides or herbicides) or PCBs can cause thyroid enlargement.
- Heredity or genetics.
- Septicemic diseases: Infections of the blood (e.g. E.coli, Salmonella) can affect the thyroid glands, which cause inflammation and goiter.
- In chickens, avian goiter is most often caused by excessive consumption of foods that affect thyroid function: soy products, kale, broccoli, cabbage, spinach, cauliflower, corn, pears, sweet potato and strawberries.
- Enlarged mass on neck
- Depression, lethargy
- Decreased immune function
- Skin and feather abnormalities
- Decreased hatch rate
- Increased embryo mortality
- Blocked esophagus
- Pressure on heart and other organs
- Weight loss
- Impacted crop
- Voice issues
- Respiratory symptoms
- Difficulty swallowing
- Sudden death due to heart failure
- Provide a balanced diet
- Ensure adequate dietary iodine
- Avoid exposure to insecticides and herbicides
The reality is I don’t think goiter is very common and something that you and I are unlikely to see. So uncommon, I had a difficult time coming up with photos to accompany this post. Even if we don’t experience it personally it’s always a good learning experience understanding the vast world of chicken health issues.
And who knows when an opportunity might arise for you to deftly slip the term ‘goiterogenic’ into conversation dazzling everyone with your esoteric vocabulary? If nothing else, reading this post might make you a rock star when it comes to doing crosswords and playing Jeopardy.
Credits: Poultry DVM, Merck Veterinary Manual, Wag Walking