Our Companion Parrots do an amazing job of adapting to our world. For the most part, they live in our homes without ill effect, while giving us pleasure and a connection to nature.
But one area we sometimes overlook is air quality. One of the most difficult (if not always obvious) challenges we have is to provide a safe and wholesome breathing environment for our birds. Human houses, closed and well insulated, are not designed for birds, whose intricate respiratory systems need fresh, moving air to stay in peak form. (See How Birds Breathe, below.)
Fumes, especially those from cooking and cleansers, can sicken and even kill house birds. In general, if you can smell it, chances are your bird shouldn't be breathing it. But what about airborne dangers that have no tell-tale scent? Like humans, birds can inhale mold spores, those nasty little organisms that grow on surfaces. We can't see them, and usually don't smell them, but spores float through the air and into our lungs. If spore concentrations are small and we are healthy, molds usually do not bother people or animals. But if we're already ill, mold can be a troublemaker. When it comes to our birds, one type of mold seems to cause more problems than all others: aspergillus.
Several types of aspergillus molds (most commonly Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, and Aspergillus flavus), all found worldwide, are capable of causing the disease of aspergillosis.
Aspergillosis can be a devastating respiratory illness that affects a bird's trachea, nasal passages, air sacs, or all three. Itís tough to diagnose - and even harder to cure. In advanced stages, it blocks airways and spreads to other organs. Aspergillosis is the most common fungal infection found in wild birds. Among pet parrots, African greys and Amazons seem the most susceptible. However, any bird can develop aspergillosis. Recently, fatal cases have been reported among Jardine's parrots. My Meyer's parrot, Froggie, died from aspergillosis.
Weak birds in danger
Aspergillosis is an infectious disease Ė but not a contagious one. It's infectious because the mold spores can grow in living animal tissue. However, aspergillosis is not considered contagious because we acquire it from our environment, not from each other. Like all molds, aspergillus needs dampness, warmth, and a food source to grow. It spreads by ejecting spores, microscopic tough-skinned seed-like structures, into the air.
If we're not careful, the very environment in which our house birds live can become a breeding ground for aspergillus. The most common places for a pet bird to come into contact with spores include dusty pellets and seeds; spoiled food such as decaying fruits and vegetables; droppings; and cage bedding that becomes damp, such as wood shavings, mulch and corn cobs. Peanut shells and peanuts also can carry concentrations of spores.
Healthy birds seem to be able to withstand spores without becoming ill, but a weak bird is in danger. Spores favor setting up shop in an animal that is ill, malnourished or immune-suppressed, or that has damaged tissue. Once in the presence of a suitable spot, each spore is capable of growing tentacle-like filaments called hyphae, which spread and take nutrients from the host animal. The hyphae, together with the white and other blood cells secreted by the animal in an effort to rid itself of the invading organisms, form a mass called a granuloma. The longer the hyphae grow and the more the host continues to resist, the larger the granuloma becomes. Eventually, the mass becomes large enough to obstruct an airway, fill an air sac, or even interfere with other organs.
Is it aspergillosis - or something else?
Spotting aspergillosis before it becomes a serious problem is a challenge. The signs are subtle, range widely and can be symptoms of other diseases. By the time you notice anything wrong, your bird can be very ill.
One symptom is weight loss, which can occur even if your bird has a good appetite. Other signs: abnormal droppings, a change in voice, and depression or other behavioral changes, including difficulty moving. Chronic aspergillosis infections are thought to trigger some feather picking, especially in African greys.
Human houses, closed and insulated, are not designed for birds, whose intricate respiratory systems need fresh, moving air. An infected bird might recover his breath more slowly after exertion or have difficulty breathing, using an open beak with outstretched neck or bobbing tail. Masses in the nasal cavity can leave nostrils with dry, crusty lesions.
Even experienced veterinarians have trouble diagnosing aspergillus. Blood tests can suggest the presence of an active fungal infection, and aspergillus can be grown from fluid and tissue samples. However, aspergillus is such a common environmental contaminant, it's easy to get false positives. Many diagnoses, unfortunately, are made post-mortem.
No instant cure
There is no instant cure for aspergillosis. Treatment can take months, and even then recovery is not guaranteed. If a lesion can be removed surgically, that is the best first step, followed by medication. Your veterinarian will probably opt for one of these traditional anti-fungal medications: 5-fluorocytosine (5FC), itraconazole, fluconazole, clotrimazole or amphotericin B. Your bird might receive medicine via shots, orally, or, to maximize penetration into the lungs, a nebulizer (a medical device that delivers liquid medication in the form of a mist to the airways).
For infections of the nasal cavity, frequent anti-fungal rinses seem to help. One or more nasal rinses a week is a daunting prospect if your parrot is difficult to handle, but it might be the only way to maintain a healthy bird.
My friend's African grey parrot, Seth, gets recurrent aspergillus infections if he does not get weekly medicated nasal rinses. Seth, a somewhat cranky bird, doesnít like the procedure, but Betty and her husband have worked out a routine. While one person towels and holds Seth, the other does the rinsing. I helped Betty after her husband had wrist surgery. I was not sure what to expect. But Betty held Seth and I rinsed each nostril a couple of times using a syringe. To my surprise, afterward Seth stood on my arm (a rare occurrence indeed), shook out his feathers, and just looked at me. We all sat for a few minutes until Seth indicated he was ready for Betty to put him back on top of his cage.
The key, I think, to Seth's successful weekly rinses is routine. Betty tells him it is time to rinse, wraps him, and does the job. Then Seth sits with the person who rinsed him for a few minutes and life goes back to normal.
If lesions are located in the air sacs, the infection is serious. Air sacs donít have a good blood supply, so not only do birds have a harder time getting their own germ-fighting cells to the site of the infection, medication has to be given in higher doses, which can cause kidney damage, among other problems. If treatment is working, your bird should begin to look and act healthier. Feather picking may stop. Birds with nasal infections may no longer have a discharge. Your veterinarian will be able to determine when to stop medication by using blood tests and observation.
Youngsters at special risk
Young parrots are at greater risk for a number of ailments, including aspergillosis. This is due in part to an under-developed immune system. Some baby birds, for instance, can develop aspergillosis before hatching when aspergillus mold spores penetrate the eggs. The hatchlings can come out of the shell with well-developed lesions.
However, hasty or inept hand feeding also can invite disease. Birds can aspirate formula into their air sacs. Overly hot formula also can damage tissue and create an ideal spot for aspergillus mold to grow. Thatís how one chick from a clutch can become infected while the rest remain healthy. A hand-feeding accident might be why my seven-month-old Meyerís parrot, Froggie, developed aspergillosis. Froggie was fine for many months. He showed no obvious symptoms until three days before he died, when he began wheezing after exertion.
Even then, I didnít realize anything was wrong. I was an inexperienced parrot owner and didnít know that the change in his voice could be a sign of illness. I thought it was normal for him to pant for a minute after he was startled and fluttered to the ground. (Iíve since learned wheezing episodes of any length, except in excited or nervous pionus parrots, are never normal.)
Even experienced veterinarians sometimes have trouble diagnosing aspergillosis. The necropsy revealed a large mass at the end of the trachea that had blocked one bronchial tube for weeks, according to Froggieís vet. When the granuloma grew larger and blocked the other bronchial tube, Froggie died.
Had I weighed Froggie regularly, I might have seen the slight drop in body weight, even though he was still eating well. But by the time he began wheezing, it was far too late. Surgery on such a large lesion positioned where it was in his respiratory tract would have killed him, and medication would not have helped with such a mass still there.
When I first got Froggie, his veterinarian put him on a course of antibiotics after a fecal stain revealed large numbers of potentially harmful bacteria. Antibiotics disrupt the natural balance of bacterial flora, sometimes inviting secondary infections, including aspergillosis.
However, I donít think antibiotics made Froggie ill. I believe he was either overcome by spores in my home, or was injured from handfeeding at the breederís or the shop where I got him. Any damaged tissue would have provided prime real estate for a few spores to get established, and one small growth could have simply taken a few months to enlarge to a life-threatening point. All of my other parrots Ė two cockatiels, two Quakers, three parakeets, a black-headed caique and a bronze-wing pionus Ė are healthy.
Aspergillosis will be continued in the August issue of Angels Wings. The article will cover ways to keep aspergillosis at bay and why some birds are spared.