Iron storage disease (ISD) is a disease of pets birds, specifically softbills, since it has not been found in their wild counterparts. It is usually associated with birds that feed mostly on vegetation rather than those that feed on meat. Most susceptible are the fruit-eating softbills, such as toucans, turacos and mynahs. But it isn’t just the softbills that suffer from iron storage disease, it is also found in lories.
My experience with hemochromatosis (iron storage disease) has been mainly with toucans and mynahs; however, many years ago I did lose a chattering lory to it. My toucan losses were almost always after the bird was stressed, usually by a move, and in every case the birds were more than 8 years old. My losses to mynahs were also most often after a move, but not always. To me, stress is the biggest factor in the onset of iron storage disease.
Thomas Roudybush wrote in 1999: “biochemical evidence indicates that immunologic stress raises the level of iron-binding proteins that function in iron transport and that synthesis of these proteins is regulated by stress hormones. With our present level of understanding of iron storage disease, it appears that nutrition is, at best, a minor player in the disease. Stress factors, as mediators of iron metabolism, need further investigation.”
Certain Foods Aid In Uptake of Iron In Pet Birds
So why is it that wild birds don’t contract ISD? Life must certainly be stressful for those in the wild, maybe more so than for birds in captivity. My feeling is it must be related to our commercial diets, yes, even the low-iron ones. (Anything below 100 ppm is said to be low iron). Our commercial foods are most likely over fortified with things that aid in the uptake and storage of iron, such things as vitamin C, ascorbic acid (citrus fruit) and vitamin A. It is believed that genetic factors are involved as well, as with ISD in humans.
Tannins and their effect, if any, on iron levels was recently studied at Texas A&M University. It was found that the addition of tannic acid (inositol) might be a reasonable alternative to feeding low-iron diets. It was also found that the tannins did not reduce the iron levels in the liver with the birds that already had elevated iron levels, but tannin did help prevent the absorption of iron.
As a bird owner, what can you do to prevent ISD? Not much! Certainly do not feed items like dog or cat food to species that normally rely on fruit in the wild, as the hemi (blood) iron in those type of diets is readily absorbed by the bird’s body, whereas the iron in fruit and vegetables is not readily bio available, so things like grapes or figs can be fed without worry.