The Pigeon Cote
Closed Aviary Concept
Dave Rupiper DVM
The Closed Aviary Concept (CAC) is a system of specific management principles by which aviculturalists maintain their aviaries in a disease-free state. The basis of these principles is to prevent the spread of disease via the most common routes; newly acquired birds, food sources, water sources, litter material and the owner.1,2
The CAC is exactly as its name implies --closed. Once the flock is free of disease it is maintained that way. The first principle involves establishing a healthy flock. This is usually accomplished by a yearly examination of the aviary by an avian veterinarian. The veterinarian should first determine that the aviary can, in fact, become 'closed.' The avian veterinarian will examine the housing, ventilation, water sources, food sources and storage, and check for pests and rodents within the breeding aviary. The nursery will be examined and the incubator, eggs, chicks and records closely scrutinized. Last, biosecurity methods will be examined to be certain disease can be monitored. Biosecurity principles employ cleaning, disinfection, vaccination, foot baths, visitor limitations, boots and sometimes protective garments. Biosecurity monitoring utilizes tests to evaluate the flock for the presence of disease, and may include; fecal examinations, fecal cultures, other cultures and occasionally blood tests and autopsies (necropsies).3
Once the aviary has been certified disease-free by the avian veterinarian, it can be maintained that way using the CAC principles. First, all supplies entering the aviary should be clean and free of disease. This includes the water source, food source, litter material and anything else entering the premises. Three measures of biosecurity should be observed at this point. The person feeding should be 'clean': infective organisms are left outside by stepping through a footbath and wearing protective clothing. Additionally, the food storage should be a separate, 'clean' area (ie. metal storage container, different rodent free building, etc.).4
Next, foot traffic should flow from the outside to the footbath, feed storage, breeding birds, nursery and weanlings, isolation birds and finally quarantined birds.5 This pathway follows from the 'cleanest' birds to the 'dirtiest' birds and prevents unnecessary cross-contamination. Not only do the supplies follow a pathway but also the birds (see accompanying diagram).
At this point, the aviary should be viewed as a six compartment system, as follows: Food Storage, Breeding Birds, Nursery and Weanling Birds, Isolation, Quarantine, and Laboratory. The only way a bird enters or re-enters the aviary is through Quarantine. Quarantine should be differentiated from Isolation, which is used for in-house ill birds. Quarantine is for new birds and those returning from shows, breeding loans and other trips to the outside world. The only reason a bird enters the breeding aviary is for the purposes of reproduction. During the 30-45 day period in quarantine, the new bird must pass diagnostic tests to be accepted as a breeding bird. Depending on your resources and previous disease problems, these tests may be as simple as casual observation or as complex as obtaining cultures, chemistry tests and serologic testing.1,3
After Quarantine and Laboratory, the bird may enter the Breeding flock
with the ultimate goal of producing offspring. The offspring will be housed
in the Nursery and Weanlings section and eventually be sold or retained as
Let's examine the CAC by comparing two aviaries, one 'open', the other 'closed'. In the 'open' aviary we can begin at any state of flock health; from disease-free to disease-ridden. It is an easy system to maintain because there are no rules for flow of materials, birds or people traffic. No quarantine, no delays in introduction of new stock from the outside, no restrictions on contact between birds, and no 'down time' for birds returning from shows or markets. We can all jump ahead to the logical conclusion should disease strike within the flock or enter with a newly acquired bird: almost all birds will eventually come in contact and we've got a major 'brushfire' to put out! Of course, almost no one pushes their luck with such and 'open' flock-- we all take some steps to prevent acquisition and transmission of disease. However, epidemiologists (veterinarians and others with a 'population approach' to disease control) and all large poultry growers will tell you that if you can come to a CAC, your flock will healthier and your expenditures for disease control will be less.
n summary, disease can be halted by employing the CAC to any aviary, flock or loft of birds. Emphasis should be placed on establishing a clean, healthy flock and limiting the birds' exposure to outside contaminants. The closer we approach the Closed Aviary Concept in our own aviaries, the lower will be our costs associated with disease control and prevention with drugs. And, the healthier will be our birds. For further information regarding avicultural management principles, contact your local avian veterinarian.