James Harris, DVM
Lack of spleen could have killed bird
 I recently lost my 8-year-old female painted conure. She became ill and died within 24 hours. She showed no signs of respiratory problems or diarrhea, but she did have digested blood in her droppings. All tests and x-rays came out fine. Because I have two other birds I had a necropsy done, and again, everything looked fine - except the vet who did the necropsy said that she could not find the spleen. Can a bird be born without a spleen? If so, what effect would that have?
-- Jonathan Lee Gibson, Bronx, N.Y.
 Like any creature, birds can suffer from atresia, the congenital absence of an organ. Of course, if the organ is a vital one, such as the heart or brain, the fetus does not survive. However, if the deformity is less severe, the animal can get along without the missing part. For instance, in mammals, atresia of teeth is fairly common. If one kidney does not form, we can usually get by with just one.
In birds, the spleen also performs a function similar to our lymph nodes (which birds do not have). It consumes old red blood cells, forms some white blood cells and produces some of the body's antibodies. It is possible that your bird never developed a spleen. However, it's more likely that the spleen shrank at some point or never grew to a normal size to begin with, making it difficult to find in a necropsy. In adult birds, the spleen can shrink as the result of stress, illness such as a virus, or even poor nutrition. In young chicks the bursa, a structure located near the cloaca, acts as a lymph node before seeding the spleen with B-lymphocytes to take over this function. If the bursa becomes diseased the spleen will not grow as it should. Whatever the cause, a missing or stunted spleen could indeed have had a bad effect on your conure. In humans, spleenectomies result in an increased susceptibility to sepsis, an overwhelming bacterial infection of the blood.
James Harris, DVM is owner and medical director of the Mayfair Veterinary Clinic in Sandy Bay, Tasmania, Australia. He founded Montclair Veterinary Hospital in Oakland, Calif., and has served as medical director and chairman of the board for the International Bird Rescue Research Center in Berkeley. Dr. Harris' numerous professional honors include California and National Bustad Companion Animal DVM Awards.
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