Aspergillosis is a fungal infection that commonly causes respiratory disease in pet birds. It can cause both upper (nose, sinuses, eye, and trachea) and lower (lungs and air sacs – a specialized part of the respiratory tract that birds have) respiratory problems or more broadly distributed systemic infections. Aspergillus is normally an environmental contaminant and is not contagious from bird to bird.
Candida albicans is a common environmental fungus that can affect the digestive tracts of birds. It is a common cause of 'sour crop' or a crop infection (ingluvitis), especially in young birds. Candida can be a primary or secondary cause of crop infections. Often, other diseases compromise the bird's immune system and predispose a bird to secondary Candida infection (candidiasis).
COVID-19 is a viral respiratory disease of humans that was first discovered in late 2019. The illness is caused by the virus SARS-CoV-2, which is a new coronavirus that has not previously been identified in humans. Certain animals can be infected by the COVID-19 virus, but it appears to be an infrequent occurrence. If you contract COVID-19, you will need to remain quarantined on your property which may make caring for dogs a bit more challenging. If you suspect that you may have COVID-19 (with or without a positive test result), you should minimize contact with your pets. Just as you would quarantine yourself from the other human members of your home while sick, you should also quarantine yourself from your pets. If you are hospitalized and your pets must be cared for by a boarding kennel or pet sitter, inform the kennel or pet sitter that you are ill, allowing them to take the necessary precautions.
The normal lens in the eye of any animal is clear and colorless. A cataract is an increase in the density or opacity of the lens; it is often observed as whiteness within the pupil. Cataracts are often seen in canaries and less often in Amazon Parrots, African Grey Parrots, and Macaws. Cataracts decrease the visual acuity of the bird and may eventually lead to blindness.
Feather loss occurs either because the bird is truly losing feathers or because the bird, or its cage-mate, is picking out its feathers. Feather-picking is often a behavioral problem, especially in the larger species of birds (such as cockatoos, macaws, and African gray parrots). However, feather loss and feather-picking can also be caused by diseases that result in irritation or pain for the bird, or damage to, or inappropriate growth of feathers. Your veterinarian may have to many perform several diagnostic tests to rule out potential causes. Treatment of feather loss depends on the cause. Feather loss and feather-picking are complicated problems; for specific advice, your bird should have a thorough work-up by a veterinarian familiar with birds.
While many owners believe parasites are common causes of skin disorders and feather loss in birds, this is usually not the case. However, Knemidokoptic mange, also called cere mites or scaly face is a relatively common disorder, particularly in some of the smaller species of birds.
Pacheco's disease is caused by a herpes virus. Many species of birds are susceptible. Cockatoos and Amazon parrots are very susceptible to the infection and usually die, whereas conures, such as the Nanday and Patagonian Conures seem to be resistant to the disease.