By Tracy Williams
The lemur species that I care for are Ring-tailed lemurs (Lemur catta), Black lemurs (Eulemur macaco macaco), and Black-and-white ruffed lemurs (Varecia variegata variegata). We have discovered hemosiderosis in all of them, some much more affected than others. (Ringtailed lemurs don’t seem to have as much of a problem with this disease as other lemur species.)
I am not a veterinarian, but I will try to explain the disease to you as our zoo vets did to me. Most captive lemur diets contain alot more iron than what a wild lemur would consume in it’s natural habitat. The iron leaves their blood circulation and is stored in their organs (particularly the liver), where it stays permanently. Here it can cause severe tissue damage, over time. There is no way to get rid of the iron that is “stored” in their tissues once it is there.
Wild lemurs’ diets contain alot of tannin. Tannin helps their bodies prevent the iron storage. On the other hand, vitamin C promotes the iron storage.
So, the solution to this problem is this:
- Limit the iron and vitamin C (as much as possible) in their diets.
- Give them as much tannin as they will consume.
Our lemurs no longer get citrus fruits, such as oranges, or any other food items that contain alot of vitamin C. We have tried to cut out as much of the iron as possible by researching the iron content of the foods we feed and adjusting amounts they are fed and/or switching to foods with lower iron content. Also, tea contains alot of tannin, so we put tea in their indoor water bottles instead of water. (Black tea contains the most tannin). They have access to water in their outdoor exhibit, but they don’t seem to dislike the tea and some even seem to prefer it over water.
The produced diets that we feed contain the following (different amounts for different species and individuals, of course): apples, pears, peaches, raspberries, blackberries (berries contain alot of tannin), bananas (alot of tannin), grapes, collard greens and endive lettuce (most greens have alot of iron, but we found these to have the least that we could find), corn. They also get fresh cut browse, like mulberry, grapevine, maple, etc., when available. They eat vegetation that grows in their exhibit.