Geriatric avian medicine (Proceedings)
This lecture will address the aging pet psittacine population's geriatric disease conditions and quality of life questions. Over the past twenty-five years, avian husbandry and medicine have undergone drastic changes, including a significant increase in domestically raised pet birds and major advances in avian nutrition. Despite the potentially adverse psychological effects of incubator hatching and hand-raising (which is a separate but critical concern), these changes have resulted in birds that are living longer. Just as in human medicine, coping with the process of aging is a necessary consequence of greater longevity.
A list of the more common problems in aging birds follows:
CataractsCataracts are found in many species of psittacine birds as they age—notably macaws, Amazons, and cockatiels. It may be that these species are more prone to this disorder or merely that they are overrepresented in the older pet bird population. If the onset of cataracts is gradual, adaptation to decreased vision usually occurs. Occasionally cataracts will occur very suddenly and the bird has insufficient time to adapt. A literature search did not reveal documentation of correlations between metabolic disease (e.g., hyperglycemia) and sudden onset of cataracts in birds. However, potential concurrent disease should be investigated.
Decreased vision or blindness understandably can frighten a bird, causing it to startle easily. The fear that comes with vision loss can also lead to increased screaming or biting. If the cataract(s) is not noticed, the owner may attribute the bird's altered behavior to other factors.
The eyes should be examined at each annual visit to detect early changes in lens opacity. Due to the small size of the exposed cornea and pupil in pet psittacines, examination of any bird with suspected ocular abnormalities by an ophthalmologist is recommended. In the past five years alone, with in-house access to ophthalmologists, the following additional ocular diseases have been detected in this author's practice when an avian patient presented for a possible cataract: KCS, corneal ulcerations, third eyelid anatomic abnormalities, hypopyon, anterior uveitis, conjunctival granulomas and infectious diseases involving the conjunctiva (Chlamydophila, Mycoplasma, pox virus), cryptophthalmia, Harderian gland adenoma and lymphoma.
Although in smaller birds, there is no treatment for cataracts that will restore vision, other diseases that may be detected by an ophthalmologic examination may have medical treatments and/or may be of significant medical import. In larger psittacines, surgical removal of cataracts is successful in many cases. A bird's general health and the degree to which the cataracts are affecting its quality of life should be evaluated prior to surgery. Commonly used mydriatics are not useful in birds due to the skeletal (as opposed to smooth) muscle found in the iris.
In any bird with decreased vision, minimal alteration of the home environment is critical. The placement of food and water dishes and perches should not be altered if at all possible. If, despite environmental accommodations, a bird with decreased vision or blindness cannot be made to feel relatively secure, humane euthanasia may need to be considered.
Septic and traumatic arthritis may occur at any age. Septic arthritis is most commonly noted in the digits of birds. Geriatric onset arthritis occurs in many species, and birds are no exception. Their small size makes radiographic diagnosis difficult. The stifles seem to be the most obviously affected, although coxofemoral joint range-of-motion limitations are common in older birds. The weight of the bird, its general physical condition, any previous injuries, and any concurrent medical conditions can all contribute to the onset and severity of arthritis. Concurrent pododermatitis is often present; likely both a cause and result of decreased activity. Malnutrition, which decreases the integrity of the plantar epithelium, and concurrent obesity are often noted in affected birds.
The cage environment, especially the variety, diameter and texture of perches, can be important in providing comfort and stability for arthritic birds, while preventing or minimizing pododermatitis. The nails should be left with sharp points if possible, to add strength and stability to the grip. Wings should not be over-clipped, so they can be used to help with balance. Some medications, such as meloxicam, are being successfully used in birds, as well as acupuncture and other holistic treatments, to decrease inflammation and discomfort.
Articular gout is also common in birds. Differentiation between arthritis and articular gout is critical due the vast differences in progression, quality of life issues and prognosis. Articular gout is excruciatingly painful, and if the bird cannot be made comfortable, euthanasia should be considered.