PSITTACOSIS - IS IT STILL OUT THERE?
On a memorable occasion in practice in New Jersey several years ago, an adorable baby blue & gold macaw was brought into our clinic for a "new bird exam". In many cases, a good pet store will encourage owners to have the young birds checked within a short time after purchase. This helps protect the baby as checks and vaccinations (if needed) can be performed, and it shows the new owner the store has confidence in the health of the birds they sell. In this particular case, the check-up almost certainly saved the young bird's life.
When little "Max" came into the exam room, I did an immediate double-take as I saw that the pinkish white
skin of the baby had an odd yellowish tinge to it. Yellowish skin means "jaundice", or liver problems, to most health professionals. Never having seen jaundice in a bird before, we immediately set out to investigate. Sure enough, the droppings of the baby macaw showed a greenish-yellow tint to the normally chalky white urates. This does mean liver disease to an avian veterinarian. Blood tests confirmed that his liver was seriously inflamed. Strangely, the bird itself was fairly bright, begging for food, and in reasonable weight. Even the crop was emptying. Both the owner and the pet retailer were extremely worried, especially since the two clutch mates of the macaw were still at the store (but looked normal). They were immediately isolated while we waited for further test results. To our surprise, the test for psittacosis (also known as chlamydiosis) came back positive. This is relatively unusual in such a young bird. The pet store was mystified as they did not have many other birds in the store, and the babies had been in the store for only a few days before the first one was sold. Investigation showed that the breeder had been using a spare room in the nursery to quarantine some new breeding amazons, and that in all likelihood one of these adults had been shedding chlamydial organisms. Perhaps a carelessly washed hand, or a contaminated smock or bowl had somehow come into contact with one of the babies or their food before they were shipped out. Max was placed on a 45 day course of doxycycline (an antibiotic related to tetracycline) and made a complete recovery. The other two babies were treated preventatively and also did well.
Psittacosis is a common and important disease in pet bird medicine. A decrease in the number of imported birds has led to a welcome drop in its frequency in large parrots. Unfortunately, however, the disease does still exist in some breeder flocks, as the parent birds often are imported. Many breeders have "open" flocks, continuously adding to their collection without necessarily quarantining and feeding medicated food for 45 or more days. Also this problem may be ?enzootic? (resident or chronic) in certain breeder flocks. Some commercial cockatiel operations have had problems with enzootic psittacosis.
Signs of psittacosis in most parrot type birds include abnormal droppings, weight loss (appetite may appear either normal or abnormal), and fluffed-up behavior or sleepiness. In addition, your veterinarian can often find changes in the blood (high white count), an enlarged spleen, and "air sac" changes even though the lungs usually remain normal. The droppings in large parrots usually show a loose, dark stool as well as excess urine (wetness). The urates, which are normally white, often turn yellowish green or lime green. Very young parrots (hand-fed babies), cockatiels, and many other types of bird may show droppings that are less typical, but still many have yellowish urates. The chlamydial organism causes liver inflammation which is thought to produce this "bile-staining" effect. Other diseases can produce similar droppings (hepatitis for example). Other contagious diseases that should be ruled out in adult parrots are aspergillosis (a fungal disease) and avian tuberculosis.
Diagnosis of psittacosis is generally based on more than one test or kind of test. In the live bird, in addition to routine blood tests and x-rays, a choanal or cloacal swab may be taken for a DNA or "PCR" test. These new high-tech methods actually look for the genetic material of the disease-causing organism, and are useful as they may reveal the active presence of the organism, when it is being shed. Your veterinarian will also likely suggest a different kind of test to back up the first one, as the elusive chlamydial organism can be present in swabs on some days and not on others. Currently popular is a serological (blood) test called an ?elementary body agglutination assay? (EBA). New chlamydia diagnostic methods are constantly being developed. Combining test results with history and physical findings is always recommended before coming to a diagnostic conclusion.
The treatment of psittacosis involves good nursing support in critical cases and immediate placement on appropriate antibiotics. In avian medicine, doxycy-cline is currently the drug of choice. Chlortetracycline is also popular and somewhat easier to use, as it is available as a medicated parrot pellet. Medicated pellets are not suitable for parrots who are very ill they should have prior treatment with faster acting medications such as doxycycline. New drugs such as azithromycin also show promise.
Psittacosis is a zoonotic disease (transmissible to humans) and, in many areas, a physician may involve the municipal department of health. Fortunately, psittacosis is rare in humans, and few people who have contact with infected birds actually come down with a clinical illness. Signs in humans include high fever, flu-like symptoms, coughing, and a characteristic type of pneumonia in severe cases ("atypical interstitial pneumonia"). Modern antibiotics perform well against this disease in humans once it has been properly diagnosed. If you are ill and are concerned that you may have been exposed to psittacosis, make sure that you discuss your concerns with your physician until you are satisfied that your doctor is familiar with the disease and can investigate the possibility if warranted. Your avian veterinarian can provide test results and/or medical history from your bird (with your permission) to your family physician or specialist if you need assistance.
Breeders keeping open flocks may prevent this disease through a quarantine/treatment program and a once yearly medicated feed regimen. For this reason, breeders may find it more convenient to maintain their birds on formulated diets, as medication (and nutrition!) is greatly simplified. If your own pet parrot is diagnosed with psittacosis, you will also find it much simpler to complete the treatment if you can switch to medicated pellets after initial direct medications.
How can a parrot owner avoid psittacosis problems? Start with a long-established supplier that you trust. Look for detailed explanations as to source of the birds, clean premises, and good separation of babies from other clutches - and from adult birds already in the store. Ask for written health guarantees and expect to have your new purchase checked by a good avian veterinarian. Practice good hygiene at home, get veterinary advice about all new introductions, and avoid boarding your bird at a commercial establishment when direct or indirect contact with other birds may occur. Watch all new birds closely for abnormal droppings or weight loss. Contact your avian veterinarian for information as soon as you have a question. These precautions should ensure a long and healthy relationship with your pet!
Louise Bauck BSc, DVM, MVSc.
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