Sudden Death Syndrome

By Elena Johnson CVC AC

SDS (sudden death syndrome) is a metabolic condition which occurs most often in commercial broilers and related Cornish breeds. Chickens exhibit a sudden attack just prior to death (37-69 seconds) characterized by loss of balance, strong muscle contractions and violent flapping of their wings. The loss of balance and flapping often causes the bird to fall forward or backward, and may turn over on their sternum or back during the flapping. Some birds also give out a loud squawk or high pitched cry during the attack. The attack is usually due to the fast growth rate and excessive carbohydrate intake that occurs in modern day broilers. It’s typical in 1-4% of broilers.

That being said, laying hens and roosters of the laying breeds don’t usually grow quickly like broilers who are ready for processing by 16-18 weeks old. However, giving too much junk food that is high in carbohydrates can cause SDS. Basically it’s a cardiac arrest. This can occur in birds of any age. Obesity is the number one cause of death in backyard chickens.