Common Aviary Diseases and Problems

By: Birdworld

It is an accepted fact that most diseases seen in aviaries are the result of poor management techniques, inadequate sanitation or diet, improper quarantine, lack of appropriate veterinary care, improper housing or nesting equipment, improper water or food delivery systems, incompatible birds housed in close proximity or other problems.

 

Bacterial Infections

 

In many aviaries, especially the smaller ones, sub-clinical bacterial infection is the most commonly diagnosed disease. This can be attributed to the fact that many facilities have water delivery systems that encourage bacterial growth. Water bowls are the worst choice of a method for watering birds. We all know that birds dunk food in their water, making a potent swill-soup that harbour and grow bacteria, possibly worm eggs, protozoa and algae, especially when birds pass droppings that also end up in the water bowl.

 

When birds ingest the microbe-laden water, they can build up disease quite easily. Most often, birds with sub-clinical bacterial infections are not obviously ill, and you certainly won't be able to tell just by observing them in their flight cages. But, when the birds are caught up for examination, there may be obvious signs of illness. The choana may be swollen or red, the choanal papillae may be blunted, there may be discharge present in the choana or nares, there may be plaques or white, ropy mucus in the oropharynx, the bird may be wheezy, there may be signs of sinusitis, the cloacal mucosa may be reddened, the bird may be thin, or there may be other subtle signs. These signs are not specific for bacterial infection, so it is important that the avicultural veterinarian perform diagnostic tests to ascertain exactly what is going on.

 

The most effective means of diagnosing an infection is to run a complete blood count (CBC) and a culture (both bacterial and fungal) from the abnormal area of an aviary bird, to diagnose exactly what organisms are involved, and which are the most effective antibiotics to treat the infections. Gram's stains are useful as a screening test, but they should never be used as a sole diagnostic tool. Random feacal culturing (without catching up the bird and performing a complete physical exam) is also not an effective method of diagnosing problems, as potentially pathogenic bacteria may be "just passing through" the gastro-intestinal tract of a bird and may not be causing problems at all. Without performing a physical exam, and a CBC, it is possible to diagnose a problem where one does not really exist, which may result in a bird (or group of them) being medicated with antibiotics unnecessarily. If the physical exam is normal, the white blood cell count (WBC) of the bird is also normal, but a potentially dangerous bacteria is cultured, then it may be worth waiting, treating with lactobacillus and acidophilus (good bacteria), and then reculturing the bird a short time later, rather than treating a bird with antibiotics unnecessarily.

 

Bacterial infections are much easier to prevent than treat. Using a watering system may be the best way to prevent low-grade bacterial infections in flocks. Water bottles are often a good option, and there are several other water delivery systems available commercially. Just make sure the lines are easy to periodically disinfect.

 

Malnutrition

 

Even just a few years ago, the top disease that would have been diagnosed is malnutrition. In recent years commercial breeders have paid close attention to the nutritional requirements of their birds and they are, for the most part, doing an excellent jo b providing a balanced, nutritional diet for their birds based on the current knowledge on psittacine nutrition.

 

Many smaller breeders also are doing an excellent job, because, by having fewer birds to feed, they may have more time to offer fresh fare on a regular basis. Nevertheless, just because a breeder offers a balanced, nutritional diet, there is no guarantee that the birds will consume it. Birds fed a major commercially prepared extruded pellets as their primary diet should not be suffering from any major deficiencies, imbalances or overdosages. However, it must be remembered that nutritional research is on-going, and not every commercial diet is appropriate for every species.

 

It should be noted that the diet of a bird should never be changed until it has had a physical exam and check-up, and been given a clean bill of health. If a bird is harbouring subclinical disease, the stress of changing the diet (especially from seeds to pellets) may precipitate a health crisis. Some birds will not eat a new diet, and may actually begin to starve to death, and if a breeder is not closely monitoring birds during the change, some losses may actually occur. It is strongly recommended that you discuss the diet you are feeding your birds with an experienced avian veterinarian.

 

Polyomavirus

 

This viral disease is still prevalent and is common in hand rearing and incubating rooms, and not in the established, closed aviary. Currently, there is controversy surrounding this virus. Since accurate DNA PCR technology is now commercially available, testing is an excellent way to control the introduction of this virus into the aviary. There are currently questions concerning which species of birds are considered latent carriers of this virus (latent means that the bird is infected for life and periodically sheds the virus, potentially infecting other birds), and which birds, if infected, will only have the virus for a specific period of time, then no longer shed the virus, nor be infective for other birds. Some researchers feel that the budgerigar is the only natural latent carrier. However, other researchers feel that non-budgerigar species of psittacines concurrently infected with another immunosuppressive disease, such as Psittacine Beak and Feather Disease or chlamydiosis, can also be long-term carriers, and even non-budgerigar psittacines that do not harbor other diseases may also be long-term carriers. There is much that needs to learnt about this disease.

 

Some veterinarians recommend that all neonate non-budgerigar psittacines receive a series of at least two vaccinations against polyomavirus while still in the hand rearing and incubating rooms, given at the manufacturer's recommended intervals. It is safest to not sell un-weaned baby birds, however, this is not always practical, so by vaccinating babies prior to their sale and exposure to other birds that may be shedding the virus, the risk of babies contracting the virus will be minimized. The adult flock should be vaccinated, as well. Vaccination programs should be discussed and decided between the aviculturist and an avicultural veterinarian.

 

Reproductive Problems

 

These are one of the most common problems in aviaries, and yet breeders will feed a non-productive pair of birds year after year and do nothing about it. They may purchase a "proven" pair of birds, and when examined it may be that they are not in fact a pair, but two of the same sex. Other birds may have severe internal papillomatous disease that is preventing them from breeding, as will chronic sub-clinical or low-grade infections.

 

Inadequate nestboxes may prevent successful reproduction. Incompatibility may also prove to be a problem, especially in the Old World Species, such as the Poicephalus group, African Grey parrots, and Eclectus.

 

Birds that don't feel safe often won't breed, and simply changing their environment may do the trick.

 

Birds with decreased fertility, increased dead-in-shell eggs, or weak-hatch neonates should receive a full work-up, as recommended by the avicultural veterinarian.

 

Chlamydiosis (also known as psittacosis, parrot fever, ornithosis)

 

This disease is caused by a very primitive bacteria that must live and reproduce within the cells of its host. Studies have shown that a high percentage of pigeons and doves carry this organism and the disease is most frequently seen in outdoor aviaries where cages and nestboxes are not protected from the droppings of these birds.

 

The vast ma jo rity of psittacines carry the Chlamydia bacterium and are able to suppress it and prevent it from becoming symptomatic. Unfortunately, when birds are placed under stress their immune system commonly becomes depressed and they then allow the infection to develop to the point where it affects the bird's health.

 

This disease is considered a zoonosis, meaning that it is potentially contagious to humans, and in some states, it is a reportable disease. The newer generations of tetracyclines are most often used for the treatment, most commonly doxycycline. This treatment should be undertaken only when prescribed by a qualified avian veterinarian. The correct treatment must be used at the proper dose for the proper length of time for a bird to be adequately treated, and there is no guarantee of a cure, although most birds can be successfully treated. There is no quick fix for chlamydiosis.

 

Prevention is obviously the most effective form of management, and this consists of having a Quarantine regime in place, preventing droppings from wild birds from affecting your birds, and minimising your birds stress levels.