Like all animals, cockatiels are prone to certain diseases and illnesses that vary from moderate to life-threatening. By the time you see that your 'tiel is ill, chances are he's very sick, as birds can easily disguise their weaknesses to avoid predators.
Nutritional Deficiencies
By far one of the most common and avoidable potential problems with your 'tiel's health is malnutrition. Vitamin A deficiency is a major problem for 'tiels whose diet consists mostly of seeds. Seeds are high in fat, but they don't have the necessary vitamins. Feeding your feathered friend a balanced diet of pellets and fruits and veggies can combat vitamin deficiencies. Many cockatiels also are deficient in calcium and vitamin D.
Fatty Liver Disease
The liver is important in keeping your 'tiel healthy because it breaks down fat. The main causes of fatty liver disease in cockatiels are obesity, metabolic disorders and exposure to toxic materials. Again, a diet rich in seeds without healthy supplements such as pellets and veggies can lead to obesity, which can result in this dangerous disease.
Fatty liver disease can result from exposure to toxic materials over a prolonged period. Common toxic materials include cleaning products, insecticides and aerosols. Symptoms of fatty liver disease include abnormal beak growth, black spots on the beak and toenails, and feathers taking on an abnormal hue.
Respiratory Problems
Cockatiels can come down with various respiratory illnesses, including wheezing, difficulty breathing, and pneumonia. Some of these are more avoidable than others. Wheezing and difficulty in breathing is often caused by your little guy inhaling millet seeds or other small seeds. Diet is also a leading factor in respiratory illnesses.
Psittacosis
Psittacosis is found in birds, humans and other animals. This disease is caused by the bacteria Chlamydia psittaci. Cockatiels are highly susceptible to this disease. Like many other diseases, psittacosis can be carried by birds who show no symptoms, who then pass it on to other birds. You might not know your 'tiel is suffering from this disease until his immune system is weakened dramatically.
Symptoms include eye discharge, lethargy, sinus infections, respiratory problems, dehydration, and yellowish, gray or lime-colored urates. Young birds and those going through stressful life changes are more susceptible.
