Hygiene Protocols for the Prevention and Control of Diseases (Particularly Beak and Feather Disease) in Australian Birds
Quarantine protocols are always viewed as overkill and too expensive before a crisis, but never after a crisis!
This report concentrates on PBFD and psittacine birds, both captive endangered species and psittacine birds in the wild. In considering quarantine aspects, other diseases that can be detected by laboratory tests are included.
Captive birds are housed in a foreign environment, a key essence of which is overcrowding, compared to that which occurs in the wild. The potential for disease to occur is greatly magnified, and so intensively managed birds should be provided with an environment that minimises the potential for disease and its spread. Biosecurity is a major part of managing intensive populations of birds. As in introduction to quarantine, please refer to the following documents:
- The methods of transmission of pathogens (PDF - 22 KB)
- The importance of boot baths, face masks and disposable gloves (PDF - 24 KB)
- Lessons on biosecurity from the poultry industry (PDF - 17 KB)
The poultry industry checklist shows the extent to which a poultry integrator will go to protect its investment in genetics, nutrition, intensification, disease control and marketing commitments. On the other hand, most aviculturists’ motives in Australia are not purely economic, since very few people make a living from aviculture. They derive pleasure from keeping and interacting with birds and from their discussions with other aviculturists. They enjoy their hobby and are proud of their ability to manage and breed a hard-to-breed or rare species. Many make money from their hobby opportunistically and this helps to partly sustain their hobby.
The great majority of aviculturists do not protect their birds from wild birds and do not have a quarantine policy. They allow other aviculturists to visit their facility and they themselves visit other private aviaries. Some take their birds to shows and return them to their aviary without going through a quarantine period or protocol. Newly acquired birds are similarly introduced to the aviary. Some aviculturists, however, will go to some effort to have a quarantine policy but it is usually ad hoc and without a technical basis, and therefore not effective.
Many of the diseases and problems that arise in aviculture (as in any farming enterprise) are linked more to mismanagement than to particular disease agents. To counter this problem, Speer (1991, 1995) proposed the "closed aviary concept (PDF - 16 KB)" (CAC) to apply to a single location enclosing all modules of an avicultural facility, with designated areas and limitation of the flow of traffic and fomites. The CAC is based on the recognition that disease agents can compromise a facility, and utilises the concepts of isolation, traffic control and sanitation to prevent this.
Biosecurity for handling threatened species bred in captivity can deal with two possibilities:
- Progeny naturally reared and released into the environment, either immediately (“hard release”) or after acclimatisation (“soft release”); and
- Progeny naturally and artificially reared and released into the environment. Limitations to this option are the ability of a facility to handle larger numbers of birds, lack of dedicated staffing and finances. It also introduces domestication to a species that is to be introduced to the wild. However, it offers more progeny in a shorter time.
The goal of a recovery program is to improve the short to long term viability of wild populations. If mismanaged, simply increasing numbers in the wild through captive breeding can decrease the long-term viability of wild populations. In order to do this, it is important that there is only one species within the confines of the facility and that basic biosecurity protocols are followed.
Clipsham (1996) discussed the areas to address when selecting a site for an avicultural facility:
- Does the local environment suit the species - it is better to manage birds in an environment that suits them, rather than having the expense of modifying an aviary complex to provide a suitable environment.
- Drainage. The site must be well drained so that there is no potential for water to pool and act as an insect breeding ground, or to remain moist and harbour potential pathogens. Dry flooring is essential.
- Potential for crop production for the birds, or harvesting natural foods.
- Legal zoning status - local council - disposal of effluent
- Are crops grown nearby? Potential for pesticide spray.
- For what is the surrounding land used for? For will it be used? Will future zoning changes make it difficult to keep birds in the area?
- If located in a large town, can become a target for theft, curiosity; and
- Proximity to poultry operations. The poultry industry has always claimed that the presence of an avicultural facility is a serious threat to poultry. The reverse applies, even more so, since proximity to poultry operations has implications in the event of zoning restrictions and possible de-stocking associated with an outbreak of an exotic or serious disease Additionally, the possibility of impacts arising from nearby avicultural operations should be researched.
Some of these principles apply to wild bird rehabilitation facilities.
Setting up an Ideal Facility
The following description applies to the setting up of an ideal facility. Birds in an existing facility can be transferred to a facility such as this after going through effective quarantine.
To prevent unauthorised human traffic and access by ground animals, the entire facility needs to be contained securely by perimeter fencing. Each module within the facility would need to be protected by an effective alarm system.
All modules within the facility must provide protection from environmental extremes.
All personnel on the facility should have an intercom system to avoid having to enter modules unnecessarily. These have the potential to act as a fomite, and care must be taken to use them only outside modules.
The general principles of traffic flow within the facility apply - young birds to old, healthy to suspect, clean to contaminated or dirty and so on.
The birds should be maintained on a high level of nutrition, since this is one of the most cost-effective means of ensuring productivity (Clipsham 1996). This can be a commercial formulated diet, or a prepared diet. With respect to the OBP, birds to be released must be offered a variety of natural foods as close as possible to what they would eat in nature (this is what happens now).
Checklist for food:
- Possible bacterial contamination of fruit prior to purchase - thorough soaking in chlorine and then wash in filtered halogen- and protozoa-free water to eliminate disinfectant residue.
- Grains may have been contaminated by bacteria and fungi prior to purchase. It is not uncommon for mice to be present in stores of grain. If possible, grain should be cultured for bacterial contamination and examined for the presence of Aspergillus spp. There should be no access by rodents or other mammals, insects or spiders, where food is stored.
- Seeds sprouted with chlorinated water should be rinsed thoroughly with filtered halogen-free and protozoa-free water before being fed to birds.
- Food preparation areas should have an impervious surface, cleaned and disinfected with 2% Virkon S for 10 minutes after use, leaving no disinfectant residue.
- All food receptacles should be cleaned immediately after use.
- Cold storage of frozen or fresh foods should be in a restricted area in the food storage area, and free of bird involvement.
- Any grain that becomes moistened should be immediately discarded.
- Use disposable powderless nitrile gloves.
- Handles and other fomites (doors, refrigerators, implements) should not be contaminated.
- Food bowls should be ceramic, stainless steel or glass, since metals may be toxic and chelate some antibiotics and other chemicals. Food bowls should be accessible from outside the aviary so as to minimise bird disturbance.
The water supply may contain metals and protozoa, as well as chemicals used to sterilise the water, such as chlorine and monochloramine. Hose-delivered water should be purged for at least 2 minutes to expel any accumulated pathogen load (Pseudomonas, coliforms). The water supply should be purified with a water purifier/deioniser. There are many models of relatively cheap devices, some free-standing that need to be loaded with water, and some that can be connected to a tap. They deliver halogen-and protozoa-free water, and all modules (including the food preparation area) should be equipped with one of these devices. Automated water systems spread pathogens and should be avoided. Water bowls should be accessible from outside the aviary, so as to minimise bird disturbance.
A proposal for the design of an Office Complex, a breeding facility without a hatchery or nursery, and a breeding facility with hatchery and nursery, showing bird movement between modules, is shown in the document Captive Breeding Facility (PDF - 162 KB).