Tonight's topic was "Solving Disease Mysteries- Cases from the files of the Wildlife Disease Labs". There are four separate labs: pathology, Zoo clinical, Animal Park clinical, and molecular diagnostic. A spectacular and interesting doctor paid a return visit to tell us of a few cases. As a general rule, I don't post names in these blogs unless requested. This is one of the tough times; we love this doctor!
The Wildlife Disease Labs examine animal tissue cells to help diagnose those that are sick and prevent others from getting sick. First the disease is investigated, and the risk is assessed. Is it really a problem? A diagnosis and a diagnostic plan are made, and if necessary, animal management intervention is implemented. The cases can be fascinating, as are some of the things that are discovered.
The first cases involved six rainbow lorikeets that had died over a six day period. Obviously, something was going on, and keepers wanted to prevent further losses. The birds were all in great physical condition, which was even stranger. Histopathological examination, which looks at the cellular "footprints" of a disease, revealed that the birds had some lung damage. A closer look showed that this was caused by a disease carried only by possums. After some surveillance, they found that possums were sleeping on an overhanging branch. Going to the bathroom in their sleep, the droppings were getting into the lori's food. Where the disease was harmless to the possums, it was lethal to the birds. Keepers trimmed the branches hanging over the enclosure, and the problem was solved. Who would've thought?
The second case was unfortunately of a twenty-two-day-old California condor chick that passed away. The condor problem is both strong and crucial, so this situation was odd and disturbing. It was found to have a pox virus. Usually in the skin, this particular pox had gotten into the organs. Now there was a major scare. Not knowing the virus' origin or if it could be passed to other condors, the entire program was in danger of being shut down. The doctors checked case histories and a (safe) sampling of native birds. It turned out that the carrier was the California towhee, a little native bird. Apparently a mosquito had transferred the virus between two birds. The great news was that no two birds of any kind could pass it between them, so neither the native nor captive populations were in danger, and the condor program was safe. More good news: the governor has passed legislation banning lead ammunition in condor areas, which will effectively eliminate the birds' main issue in the wild. Yay!
The doctor told us about a baby lion tailed macaque that was getting hypothermic. The mother had two children previously, both without issue. Hypothermia is usually only found in the babies of inexperienced new mothers. Doctors asked keepers to try and locate some of the placenta in the enclosure for examination. Compared to normal placental tissue, the sample they looked at was awful. They shone a special light through the sample and noticed a crystalline structure spread throughout the cells. That particular structure is only found in one thing. The keeper had accidentally picked up a little piece of leftover sweet potato. =) The baby macaque ended up just needing a little extra care than most and turned out just fine.
The discussion was rounded out with two cases of large apes. A mandrill was showing some arm weakness for two days and was examined for possible causes, but then sadly passed away the next day. Doctors found free-living amoeba in the mandrill's brain, which can develop cysts. A special protozoologist at the CDC used a process called immunoflorescence to attempt to identify it. There are six different species of amoeba, and they can be identified by which particular lit antibody flourishes on it. However, this one eluded them all. Years later, a thirteen-year-old gorilla was experiencing weight loss and lethargy. Keepers assumed at first that she was grieving the recent loss of an older gorilla. When she did not improve, she was checked out and found to have abdominal masses and liver damage. Was it cancer? A biopsy revealed that is was amoeba! The doctor called the CDC and found that they had since identified the previous amoeba as a new species. An examination of the gorilla's water was officially reported to contain a "cornucopia of weirdness", including this new amoeba, and the water sources in her enclosure were replaced. The new amoeba was named Balamuthia mandrillaris, in memory of the first mandrill. Research into thirty years of records revealed a total of five cases, including these two, where this amoeba was the culprit, always in old world primates. This research has helped doctors to identify this condition in some AIDS patients as well. The whole talk was fascinating, and the doctor presented the cases in an understandable, mesmerizing, and often humorous way. I can't wait for him to come back- thank you doctor!
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