Maintaining live birds in captivity is expensive, time consuming, and requires special expertise. That expertise can often be found outside the community of academic or governmental ornithologists. Zoos are an obvious source of help and information. Private aviculturists are often eager to share their expertise. Investigators wishing to establish long-term colonies of captive birds are urged to contact their local avicultural societies. The American Federation of Aviculture's monthly magazine, The Watchbird, contains articles concerning the husbandry of a wide variety of birds, discussions of health problems and their treatments, and advertisements for many products and services.
Choosing appropriate veterinary assistance is critical. Clearly, a veterinarian with experience in avian medicine is preferred. Sources of information concerning wildlife veterinarians include your local zoo, the American Association of Wildlife Veterinarians, and the American Association of Zoo Veterinarians, and the Wildlife Health Information Palmer-ship. Members of the American Association of Avian Veterinarians may also help, but are
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more concerned with pet birds. [see Appendix A for Internet sites] Veterinarians who routinely work with wild birds may need a Rehabilitation permit from the USFWS and equivalent state permits, but no but no special permit is required. depending on the exact nature of their work. For routine care and maintenance, there is a distinct advantage in having available the services of an on-staff Registered Animal Health Technician or equivalent (the title varies among states) .
The living conditions of birds should be appropriate for each species and contribute to their sound health and comfort. Housing, feeding, and nonveterinary care should be directed by a person (generally the investigator) trained and experienced in the proper care, handling, and use of species being maintained. Investigators maintaining captive flocks of wild birds should refer to the King et al. (1977) or Ritchie et al. (1994) for a thorough listing of husbandry requirements of particular species. The following summary applies to birds being held for 30 days or longer in captivity.
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B. Quarantine and Isolation of Animals
Generally, all newly acquired birds shall be kept in strict isolation from other captive populations for a minimum of 30 days. Caretakers should deal with these birds last and not return to other housing areas. The quarantined birds should be observed for symptoms of disease. Fecal examinations for intestinal parasites and visual examination for external parasites should always be performed. Diagnostic procedures for Salmonella, Chlamidia, tuberculosis, and other significant diseases of concern should be considered. A wildlife health professional should be consulted for assessment and testing. Quarantine regulations for imported birds (except migratory birds between U.S. and Canada) are defined by AWA. Special regulations apply to psittacines and ratites.
Specific protocols may require some modifications of strict quarantine. For example, in song learning experiments, nestlings or fledglings of known age taken in the field may have to be transferred directly into a laboratory experiment such as an anechoic chamber, which should serve as a quarantine space if possible.
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C. Prevention, Diagnosis, Treatment, and Control of Animal Diseases
The investigator or other qualified person should observe all laboratory birds daily for clinical signs of illness, injury, or abnormal behavior. All deviations from normal and deaths from unknown causes should be reported at once to the investigator and person responsible for veterinary care. Investigators should be aware that, by the time a birds looks ill, the illness is usually well advanced. Therefore, immediate response to apparent illness is required. The potentially ill bird should be separated (isolated) from healthy birds immediately. Common signs of illness include:
a. an unwillingness to move; listlessness;
b. "fluffed" feathers - a bird looking cold when others are fine;
c. closed or half-closed eyes; an unusually sleepy bird;
d. drooping wings;
e. limping or unwillingness to put weight on a foot;
f. any change in stool consistency;
g. feces adhering to feathers around vent [see F: Sick or ailing birds].
If the illness is contagious, by the time it is detected other birds will likely have been exposed, and additional treatment may be necessary. Consult a veterinarian immediately. All laboratory or aviary birds that die from reasons other a planned portion of the experimental design should be submitted for to a veterinarian for necropsy..
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D. Separation by Species and Source
Several species may be routinely held in a single facility, provided the requirements or habits of the species are not in conflict; e.g., nervous and raucous species should be separated. Although some experiments may necessitate physical separation of species, others may require mixed-species housing (e.g., a study of brood parasitism by viduine finches on estrildids, or a study of interspecific song acquisition).
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Studies of social behavior of group-living species may require housing birds in groups in the same enclosure. Because of the diversity of housing needs, the method of housing must rely upon the expertise of the investigator. Care should be taken not to mix species if one may carry a disease that is fatal in the other, e.g., conures and macaws.
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Staple food: Animals should be fed palatable, uncontaminated, and nutritionally adequate food daily or according to their particular requirements, unless the experimental protocol requires otherwise (Guide). Because diets are highly specialized, they must be tailored to the species in question. A zoo nutritionist or veterinarian should be consulted before formulating a diet or adding grit, vitamins, or other supplements to an existing diet.
The form and presentation of the food is important to many species. Some species may become "addicted" to certain foods, e.g., sunflower seeds, and will refuse anything else, even to the point of severe malnutrition. Hence, it is important to establish a healthy, varied diet early in the life of hand-raised birds.
Grit: Many birds may require grit in their gizzards to process their food or as a source of minerals. Commercial sterilized bird grit is available from feed stores or pet stores in bulk. Crushed oyster shell or sterilized crushed hen's egg shells may be mixed in the grit as a source of calcium and other minerals. Grit may help to prevent "egg-binding" during the breeding season. Some investigators may prefer incorporating calcium and minerals directly in the staple diet. Egg shell is sterilized in an oven at 175 EC for 40 minutes before being crushed and provided to the birds.
Vitamins: These should be included depending on the quality of the bird=s rations; avoid vitamin toxicities. Vitamins are available as water-soluble (e.g., Avitron7 or Vitapol7) powder from pet stores or feed stores. Multivitamin powder (especially Avia7) is used by some investigators. Some supplements are meant to be placed in bathing water and ingested during preening. This is a handy technique for finicky eaters.
Water: Fresh water should be given daily for species that require water. [cf. J] For species normally taking water baths, water should be provided in open containers to allow bathing. Some birds may be misted for feather maintenance. Water for drinking may also be provided in commercial bird-drinking tubes (e.g., Edstrom Industries, Inc.). Drinking tubes for small mammals (nipple waterers) may be used if birds will adapt to use them - some birds will refuse to drink from these. Automatic tube watering systems reduce leakage onto cage liner material, thus reducing the growth of fungus, and the main water source can be cleaned without opening the cage. Water containers should be washed daily [cf. J] with soap and water and at least twice weekly with diluted household bleach. Containers should be of non-porous materials, e,g., glass, glazed porcelain, plastic, or stainless steel. Perches should not be placed directly over water receptacles.
Cleaning: Cage liners should be changed often enough to maintain good hygiene. Seed-eaters usually have relatively dry feces, and their cage bottoms may be lined with newspaper and changed twice weekly. Insect and fruit eaters tend to have messier (and smellier) droppings and should have the cage trays (bottoms) cleaned at least every other day depending on how messy the particular species is. [cf. J]
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F. Caging, Housing, and General Maintenance
Cages: Stainless steel, galvanized steel, fiber-glass, or plastic cages permit easy cleaning as they may be put in a steam-cleaning machine when necessary. New cages containing galvanized steel or galvanized mesh should be brushed with a wire brush and vinegar solution before they are first used to reduce the possibility of zinc poisoning (Howard 1992). Similarly, any soldered joints should have a protective coating to prevent lead poisoning.
If the birds are easily transferable between cages, then cages should be thoroughly cleaned every three months (once per quarter). Cages should always be thoroughly cleaned with a disinfectant after use by one bird is completed and before another is introduced. Steel (galvanized or plain) showing surface rust should be thoroughly cleaned, buffed, primed, and painted with epoxy paint to prevent rust. If experimental designs require the use of wooden-and-wire cages, then these should be checked for mites. Pyrethrin sprayed into
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cracks and corners will kill these pests, Cages that have been infested with mites can be treated with boiling water. Cages, runs, and pens should be in good repair and devoid of sharp protrusions that might injure the birds.
Minimum Cage Size: Cages should provide sufficient room for normal maintenance behavior and wing-flapping. Minimum size depends on whether birds are just being maintained in the laboratory or whether breeding is desired. Because of the diversity of avian species, investigators must assume responsibility in determining adequate cage size.
Cage Bottom: Paper, fine sand, wood-shavings, or (ideally) newspaper may be used on cage bottoms. Avoid ground, dried corncobs (Sanicel7), walnut shells, or any other substrate that may promote the growth of fungi, especially Rhizopus and Isospora. The probability of fungal infections accrues over time, so that even large flight cages or aviaries need to be disinfected at regular intervals. Bocetti and Swayne (1995) recommend disinfecting aviaries annually with a combination of A-337(Ecolab, Inc), 5% sodium hypochlorite, and a methyl bromide fumigant. Cages with wire bottoms and traps may be used for some species (e.g., some galliforms). They should be avoided for seed-eating song birds as some individuals may knock their entire seed allotment through the wire.
Perches: Perch type should be appropriate to the species. Perches should provide good footing with a minimum of trauma. They should be made of durable and sanitizable materials such as metal, plastic, or PVC, or of economically replaceable material such as wood. Wooden perches are preferred for small birds; ideally, natural branches of different sizes should be used. As long-term use of metal or plastic perches increases the incidence of bumble-foot due to slippage, it may be necessary to wrap the perch with a non-abrasive, non-slip surface, e.g., raptor keepers often wrap rope around a core. Perches should not be covered with sandpaper. Toenails and beaks should be pared routinely to avoid overgrowth. Investigators should be aware that inappropriately sized perches will lead to leg swelling. A variety of perch sizes is advised.
Cleaning: Water dishes should be washed daily and seed dishes should be washed twice weekly using a safe and effective disinfectant Such as sodium hypochlorite (household bleach diluted 1/10 (Smith 1990). [cf. K] Quaternary ammonia compounds may be used to disinfect cages, laboratory counters, and floors. Industrial wet/dry vacuum cleaners are useful aids in floor maintenance. Small, hand vacuum cleaners are useful for spot cleaning. Investigators should not use these when birds are breeding, as undue disturbance may cause nest disruption [see 111. C]. Water bottles should be washed twice weekly.
Nest Boxes and Nesting: Although metal boxes can be used for some species (e.g,, large psittacines), many species prefer (or require) wicker or wooden nest boxes into which they can carry grass, coconut fibers, excelsior, or feathers. Parrots and parakeets also breed in wooden boxes into which a layer of wood shavings may be introduced. Emberizid finches may build in bushy boughs tied together in a bunch to simulate a bush, or in a potted Boston fern or ornamental bunch grass.
Outdoor and Indoor Aviaries: Climate and facilities permitting, birds may be housed in outdoor aviaries. At least one side of the aviary and part of the roof should be covered to protect birds from wind and rain. Larger outdoor aviaries may contain a permanent covered enclosure to serve this purpose. Perches of different sizes should be provided. Shrubs and trees in pots or planter boxes, or planted on the ground in the aviary, will enable birds to hide when potential predators (cats, raptors, strange humans) are sighted. This gives the birds a sense of security and promotes well-being. Bunches of leafy boughs lashed together with rope or wire and hung on the aviary sides or shelter walls can provide the same effect. Grass may be planted on the aviary bottom if desired. Plantings may attract insects relished by many birds. Half-ripe grass seeds are also a favorite food item. A black-light trap may also be installed to attract live insect food.
Extreme care must be taken with outside cages to prevent access by predators. Climbing predators are especially dangerous. Single raccoons are known to kill confined birds as large as cranes. Further, raccoon droppings may carry parasites (Baylissascaris procyonotis) capable of attacking the avian central nervous system (Ritchie et al. 1994).
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The floor of indoor aviaries may be covered with newspaper, sand (commercially available), or wood shavings. Sand and wood shavings should be replaced at regular intervals to reduce the build-up of enteric bacteria and fungus. Wood shavings may require prefilters to prevent clogging of air filtration systems. Such systems may rapidly accumulate, and become a source of, fungal spores. They should be changed monthly (Bocetti and Swayne 1995). Environmental enrichment with branches and/or vegetation is desirable. For some species wire floors may be used. Walls of large cages, racks and tables or other furnishings constructed from porous materials should be coated with a durable moisture-proof, seamless substance (e.g., epoxy paint, spar-varnish, etc.). These paints and glazes should resist cleaning agents, disinfectants, and scrubbing.
Lighting: Many aviculturists believe that it is advantageous to use full spectrum (UV) light sources in indoor facilities. These bulbs should be replaced every six month. The practice, however, is controversial, indicating another instance in which consultation with a veterinarian would be useful. A small night light placed near the food source is desirable in cold weather use of outdoor aviaries. A night light is also useful to alleviate stress in recently captured birds and in certain experimental protocols.
Unless experimental protocols dictate otherwise, birds normally should be maintained on photoperiods natural to the species. These may vary with the species, and the schedules of long and short photoperiods must be left to the discretion of the investigator, as these schedules are often tied to an experimental time table and may differ according to species.
Temperature: A temperature range appropriate to the species should be maintained with a thermostat-controlled heating source. Many birds readily acclimate to a wide range of temperatures. However, extreme temperature changes may be lethal at worst and stressful to the immune system at least, and birds should be kept away from areas with appreciable fluctuations in temperature. Normally, room temperatures should be checked daily. in outdoor aviaries, a heat source may be necessary. Infrared bulbs, which will not interfere with light/dark cycles, or non-light radiant heaters are commercially available in pet stores.
Humidity: Humidity should be kept within the range normal to the natural environment of the species if normal behavior and reproductive success are expected. Hatching success of eggs of some species is sensitive to humidity.
Storage of feed and supplies: Supplies and equipment should be stored in cabinets or rooms that can be fumigated and are not used to house animals. These cabinets or rooms may be in or adjacent to aviaries. All feed should be stored in rodent-free, covered containers. Animal keepers may find it convenient to keep some feed in the laboratory. Containers should be plastic or metal but not glass. They may be housed in close proximity to the bird colonies or aviaries. Ideally, food should be kept at temperatures <22 EC or refrigerated at <4 EC. The shelf life recommended by the manufacturer should be noted and containers marked with expiration (discard) dates.
Disposal of waste material: All garbage cans holding waste material (e.g., from cleaning cages) should be kept outside the immediate area of the laboratory. Use of garbage liner bags and daily removal of garbage is encouraged.
Dead animals: Dead birds should be labeled as salvage specimens, placed in plastic bags and refrigerated (frozen if storage is to exceed a 24 hours) away from the holding facilities. The cage should be washed with water and disinfected after the carcass has been removed. We recommend that all dead animals be scheduled for necropsy. "Fresh" necropsies are preferable, but if at is not possible, the animal should be sprinkled with water containing detergent, refrigerated in a sealed plastic bag (after being cooled), and taken to the veterinarian as soon as possible. If a delay of longer than 24 hours is likely, the cadaver may be frozen.
Mopping of floors: Laboratory floors should be swept regularly and should be maintained in a clean condition. [cf. J] Sodium hypochlorite (household bleach) diluted 1/10 or other appropriate disinfectant may be used to sanitize floors.
Provisions for emergency care: Names, addresses, and phone numbers of consulting veterinarians, and individuals responsible for the animals should be prominently posted. Provisions should be made for observations and care of animals every day, including
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weekends and holidays, to safeguard their well-being and to satisfy research requirements. Emergency numbers of both caretakers and physical facilities should be posted in a prominent place.
Sick or ailing birds: An unhealthy bird will usually sit with fluffed feathers, and eyes closed or half-closed. Droppings may look watery, and feathers around the cloaca may be smeared with feces. A sick bird should be moved to a room designated temporarily as a treatment room. A heat-lamp should be provided, but only one corner of the cage should be heated, and the lamp should not be closer than is comfortable for your own hand. The bird must have the opportunity to move away if it gets too hot or it may die of heat-shock. Seek a veterinarian's help. Small incubators or commercial brooder units are ideal to hold ailing birds, but be sure that the unit can be disinfected later. Weight gain or loss is a good indicator of general health. A weight loss of more than 10% should be evaluated by a veterinarian.
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G. Special Considerations for Aquatic Birds
Aquatic species have needs that are distinct from those of other birds; these mainly have to do with the anatomy of their feet and the importance of waterproofing in their plumage. Species differ widely, so no single prescription will apply to all aquatic birds. Nonetheless, some general rules apply.
Waterproofing of plumage: Maintenance of waterproof plumage is fundamental to the comfort and health of all aquatic birds and requires access to absolutely clean water. Aquatic birds must be allowed to bathe at least once a day. Diving or pelagic birds require cages or enclosures that allow swimming as well as exit from the water.
Access to water: In general, merely providing pans of water in the cage is not acceptable unless the pan is large enough to allow bathing and water is changed frequently. How frequently will depend on how rapidly a surface film of dirt, feces or dropped/dunked food forms. Even very light films will interfere with waterproofing. In most cases, pans of water should be changed at least twice daily. If it is possible to provide it, a flow-through system for water is less labor-intensive, more effective, and disturbs the birds less. Such systems should have a constant input of clean water and drain constantly from the surface.
Drainage from the surface can be accomplished either by use of a standpipe in the drain, or by overflow over the top edge of the pool/pond/container. Very simple systems can be created by putting a running hose in a commercially available, plastic, child's swimming pool, and letting the water overflow the top. Where standpipes are used, the top of the pipe must be covered with screen or netting of small enough mesh to exclude the birds' legs and toes. If drain water is filtered instead of thrown away, filtration must remove bacterial and viral pathogens as well as particles that cause surface films. Rubega and Oring (pers. obs.) report excellent results keeping shorebirds in a filtered system that employs activated charcoal and a UV sterilizer, and filters down to 2F. In any flow-through system, feces and food will tend to accumulate at the bottom. These must be removed by siphoning or wet- vacuuming at least twice weekly, but as frequently as is required to prevent decomposition and/or stirring up into the surface layer.
Flooring and foot problems: Aquatic birds are highly susceptible to wounds and infections of the feet and legs. These result primarily from pressure sores developed when the bird is forced to stand for long periods on hard flooring. These sores subsequently become infected when birds walk in feces or dropped food. Infections of this kind are painful and debilitating, and can cause the loss of digits or limbs. Untreated infections occasionally lead to slow and painful death and always lead to some loss of function.
For birds that will be held for more than 2 to 3 days, cage or aviary bottoms must be lined with some resilient material. Sand is commonly used, but must be raked free of feces frequently. Sand must also be completely replaced frequently to avoid creating a bacterial reservoir [see F: Cage Bottom]. Rubega (pers. obs.) reports good results with shorebirds and gulls by laying down mats of commercially-available rubber or plastic carpet padding, replaced and washed daily. Better results are attained if mats are flushed with constantly running water in the cage. Rubega and Oring (pers. obs.) have recently had excellent results with shorebirds by flooring with a commercially-available, slip-proof, rubberized waterproofing system called Tufflex7, also flushed constantly.
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Regardless of the flooring used, investigators should be aware of the potential for infections. Any bird that shows signs of limping, reluctance to put weight on a foot or leg, redness, or swelling in the feet or legs should be closely examined immediately. The presence of foot sores requires immediate (and repeated) treatment with a topical disinfectant, isolation from other birds, and modification of cage flooring. In general, unless the investigator is very experienced, advanced cases should be referred to a veterinarian for treatment.
Raptors have long been maintained in captivity in connection with the sport of falconry.
Discussion of techniques associated with that activity is not appropriate here. However, in recent years breeding programs for several species of raptors have been established for management purposes, and research with raptors may involve the use of captive birds. Most procedures outlined in this document apply to these programs. Procedures applicable specifically to raptors are discussed by Carpenter et al. (1987) and Redig et al. (1993) see also VI.A].
A waterproof label should be attached to each experimental cage containing the following information:
a. identification and number of animals;
b. date experiment started, and projected end (approximate);
c. any special instructions on feeding (may be in code);
d. name of responsible investigator.
Records should include source and eventual disposition of each animal. It is recommended that birds be leg-banded with plastic or metal bands to facilitate identification of individuals. Permit and protocol numbers should be prominently displayed in the animal holding room. The investigator is responsible for maintaining records concerning the histories and dispositions of all individual birds as required by local, state, and federal law.
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J. Disposition of Birds after Experiments
Upon completion of studies, researchers should release field-trapped specimens whenever this is practical and ecologically appropriate. Exceptions are if national, state, or local laws prohibit release, if release might be detrimental to the existing gene pools in a specific geographic area, or if the specimen has been exposed to potential pathogens that could be released into wild populations.
As a general rule, field-trapped animals should be released only:
a. at the site of the original capture, unless conservation efforts or safety considerations dictate otherwise. For these latter exceptional circumstances, prior approval of relocation should be obtained from appropriate state and/or federal agencies, and approved relocations should be noted in subsequent publication of research results.
b. if their ability to survive in nature has not been irreversibly impaired by major structural or physiologic damage, e.g., surgical deafening. Birds that have been so impaired but are otherwise healthy may be donated to zoos or other appropriate organizations. [see IX. G]
c. when local and seasonal conditions are conducive to survival.
d. if there is no chance that they have been exposed to a transmittable disease.
Prior to release, each bird should be examined for signs of injury or disease; birds unlikely to survive should not be released. Birds should be released early in the day and during favorable weather so that they will be able to feed and locate suitable roosting sites before dark. Released birds should not bear the color bands that fit the color sequences allotted to a licensed bird bander. Captive animals that cannot be released should be properly disposed of, either by distribution to colleagues for further study, by donation to a zoo or aviary (it is illegal to distribute migratory birds as pets, and generally inadvisable to distribute even those species common in the pet trade to other than serious aviculturists), or by preservation and deposition as teaching or voucher specimens in research collections.
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In both the field and laboratory, the investigator must be careful to ensure that euthanized animals really are dead before disposal. in those rare instances when specimens are unacceptable for deposition as vouchers or teaching purposes, disposal of carcasses must be in accordance with acceptable practices as required by applicable regulations. Animals containing toxic substances or drugs (including euthanasia agents such as barbiturates) must not be disposed of in areas where they may become part of the natural food web.
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K. Variations on Standard Procedure
In most experimental protocols it is desirable to keep disturbance due to routine inspection, maintenance, and feeding activities to a minimum. Captive-breeding birds may desert nests if disturbed frequently, and behavioral patterns may be disrupted for several hours (or even permanently) if subjects can detect intrusion or potential intrusion (noise/sight of investigator or animal keeper). In these cases, routine daily inspections should be suspended, and a schedule should be established for feeding, watering, and cleaning that minimizes interference with data collection but simultaneously ensures health and well-being of the experimental subjects. For example, cages can be cleaned twice weekly instead of daily, conditions can be checked by observation with video monitors or through one-way glass screens. Fresh water and food can be provided to last for several days. Containers can then be removed, washed, and sterilized twice weekly. In some circumstances, an investigator may be able to reduce intrusion even further by employing mechanical means of providing food and water, e.g., automatically filling or rotating food hoppers, drip tubes, etc. Frequency of disturbance can be left to the discretion of the investigator provided that the well-being of the subjects is not compromised and that the procedure has been included in an approved experimental protocol.
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Beyond the ethical considerations of handling birds, investigators must be aware that the routine handling of animals incurs certain personal risks. Clearly steps must be taken to protect the handler from dangerous species, or even aggressive species that may attack with painful if not serious results. [see IX.C] Further, a variety of diseases are transmittable from birds to humans (Evans and Carey 1986). Common among these are campylobacteriosis, histoplasmosis, ornithosis, tuberculosis, salmonellosis, and Yersinia spp. (enterocolitia and pseudotuberculosis).
The most well known of the above diseases is a form of chlamydiosis known as ornithosis, often, but inaccurately, termed psitticosis or parrot fever. In fact, this highly contagious agent (Chlamydia psittac/) is known from more than 120 nonpsittacines and several domesticated mammals (Gerlach 1986). Its symptoms are flu-like, and, because it is not a common disease, it is often misdiagnosed. Bird handlers suffering from atypical pneumonia,
recurring fever, or from otherwise unaccounted-for chest pain, anorexia, dyspnea, or profuse sweating should inform their physician of the possibility of ornithosis. Note that the standard antibody test is subject to a cross reaction with Chlamydia trachomatis, a human venereal disease. See the AVMA publication Zoonoses Updates for more recent information.
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