Skin and Feather Disorders of Pet Birds
Skin and feather disorders are among the most common health problems seen in pet birds. Loss of feathers and skin disorders can be signs of a local disorder (that is, one that only involves the skin or feathers), or they can be signs of general, system-wide disease.
Feather cysts occur when a growing feather is unable to protrude through the skin and curls within the follicle. The ingrown feather results in a lump or mass that continues to grow as the feather enlarges. Feather cysts appear as oval or elongated swellings involving a single or several feather follicles. Although they may occur anywhere, in parrots they most commonly involve the primary feathers of the wings.
Feather cysts may be seen in all species; however, they are most common in blue and gold macaws and certain breeds of canaries. The cysts may be the result of an inherited predisposition, as in certain species of canaries, or acquired as a result of infection or trauma involving the feather follicle. The condition can be treated by surgically removing the involved feather follicles. If the follicle is not removed, the condition will usually recur. In canaries with multiple cysts, surgery is not usually practical.
Feather plucking refers to behaviors in birds that can range from mild overpreening to self-mutilation. There are many different possible causes of feather plucking, both physical (such as disease, parasites, or allergies) and psychological (such as stress or boredom). Good communication with your veterinarian concerning the problem is necessary in order to improve the health of the bird and to reduce or eliminate the plucking behavior if possible.
Feather plucking seldom has a single factor as the cause, and all possible reasons should be explored, including underlying medical problems. Possible medical causes for feather plucking include skin or internal parasites, liver disease, cancer, allergies and other inflammatory skin conditions, infectious diseases, metabolic or nutritional disorders, or heavy metal poisoning (notably zinc).
Malnutrition is likely a more common contributing factor to feather plucking than the medical conditions listed above. Basic seed and table food diets often create nutritional deficiencies that cause abnormal skin and feather development. This can result in plucking behavior, as well as many other medical problems. The dyes and preservatives added to seeds and many pelleted diets may be detrimental to birds or can cause allergies. The relatively low humidity in most households also has a drying effect on the skin. Being deprived of natural sunlight, fresh air, humidity, and the normal light/dark cycle has negative physiologic and psychological effects on birds.
Behavioral feather plucking may be diagnosed after a complete evaluation has eliminated many of the other medical and nutritional causes. Treatments will be based on the underlying cause.
Addressing the medical and environmental factors may reduce the severity of feather plucking, but a strong behavioral component is often involved as well. Treatment of some of the above mentioned problems may lead to initial improvement, followed by a relapse. Psychological stressors can lead to feather plucking. Psychological conditions that may cause feather plucking in birds vary. Excessive stimulation may cause plucking in one bird, while another bird might pluck out of boredom. Unfortunately, once the stress has been relieved, the habit may still remain.
Feather plucking does not occur in the wild, where birds are occupied with finding food, maintaining their social status in the flock, seeking a mate, avoiding predators, and breeding and raising young. Therefore, often the best-kept birds, which have all their apparent needs met, will pluck feathers for behavioral reasons. Owners of these birds often report that their birds are more territorial, more aggressive, and may be showing sexual behavior toward a perceived human mate or inanimate objects.
A thorough understanding of the bird’s environment and the associated behavioral changes that have accompanied the onset of plucking is required in order to treat the problem. In some cases, simple changes in the environment, such as moving the bird’s cage to an area where the family often gathers, will help. In other birds, environmental changes are combined with medical treatments such as hormones or drugs to reduce anxiety or aggression. However, available drugs do not tend to produce longterm positive results, and side effects may be seen. In addition to traditional medical therapies, acupuncture and dietary supplementation with omega fatty acids have been reported to be helpful in some cases. Referral to a behavioral consultant may be useful.
Inflammation of the skin may result from infection with various organisms. Bacteria, including staphylococci, streptococci, and Bacillus species, are thought to be responsible for most skin infections in parrots. Staphylococci are often isolated from areas of pododermatitis (bumblefoot) in many avian species. Your veterinarian can identify and prescribe appropriate antibiotics for these bacterial infections, if necessary. Inappropriate husbandry and nutrition are often contributing factors. Recently hatched and young birds are especially susceptible.
Various fungal infections can affect the skin of pet birds. Ringworm, a fungal infection, is occasionally reported in pet birds. Cryptococcus fungi have been rarely reported to cause facial dermatitis in birds, but because this organism may also cause infections in people, it should be considered in cases of true skin infection. Skin inflammation caused by the yeast Malassezia has been reported in caged birds that are feather picking. Your veterinarian may prescribe a medication given by mouth or a topical spray to treat these infections.
Scaly face or leg mites are common in budgies but rare in other parrots. The mites cause a mange-like condition on the face or legs of affected birds. Signs of infestation include white crusts around the corners of the mouth, nostrils, beak, and occasionally the area around the eyes or the legs that may cause deformities if not treated. Even after successful treatment, beak deformity may still persist. Other species of birds such as canaries and finches can also become infested with this parasite, but have different signs, such as crusts that form on the legs and surfaces of the toes (commonly called tassel foot). Itching is not usually seen. The mites can be diagnosed from skin scrapings taken from affected areas. The veterinarian will most likely prescribe an antiparasitic drug that is given by mouth or by injection.
Feather mites rarely affect pet birds, despite popular belief. Occasionally, infestation with red mites may be found in outdoor aviaries. Signs of feather mite infestation include restlessness (especially at night), anemia, and death, particularly in young chicks confined to the nest box. Covering the cage at night with a white sheet and examining the underside of the cover the following morning aids in collecting and identifying mites.
The veterinarian may prescribe a spray, powder, or other medication that is given by mouth or by injection for treatment. Nest box treatment includes mixing a medicated powder into the nest box bedding. Cages should be cleaned thoroughly, and wooden nest boxes may need to be discarded and replaced.
Psittacine beak and feather disease is caused by a virus. The name “beak and feather disease” is somewhat misleading, because the typical signs do not include beak abnormalities and are less likely to have the severe feather abnormalities that were seen in cockatoos when the disease was first documented. This serious infection has been reported in wild and domestic birds. Screening for the virus has greatly decreased its presence in cockatoos; however, the disease is still noted in African Grey parrots, Eclectus parrots, lovebirds, lorikeets, and other species from Old World locations such as Asia, Africa, and Australia.
Infection occurs primarily in young birds, with few instances of infection seen in birds over 3 years of age. Typical signs include feather loss, (including areas where the bird could not reach to pluck itself), abnormal pin feathers (constricted, clubbed, or stunted), abnormal mature feathers (blood in shaft), and lack of powder down in some species. Pigment loss may occur in colored feathers. More rapid infections can also occur, with several days of depression and sudden death.
Psittacine beak and feather disease is spread by direct contact with affected birds and by spread of feather dust, dander, and fecal material. It may be spread from adults to offspring and may even be contracted from a nest box which has been unused for many months or years. The virus is very stable in the environment and is resistant to disinfectants.
Affected birds should be isolated; often it is recommended that they be euthanized. There is no effective treatment, but supportive measures may increase the length and quality of life. Strict hygiene with attention to dust control, diagnostic screening methods, and lengthy quarantines are highly recommended in cockatoo breeding colonies to prevent the establishment and spread of this disease.
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