Telltale Signs
Mallophaga: These include a number of species of biting and chewing lice. Clinical signs are mild or absent; however, heavy infestations do indicate other diseases are present. Attacks many birds, particularly cockatiels and canaries.

Scaly Face Mites: Rare on most birds, other than budgerigars. A white, porous, crustation can be seen around the mouth, cere, eyelids and beak, and the beak might become deformed. In passerines, long smooth crusts form on the plantar surfaces of the toes ("tassel foot").

Feather Mites (Red Mites): Signs of infestation include restlessness (particularly at night), intense itching or anemia. Heavy infestation may lead to death. These mites rarely affect caged birds, but are occasionally seen in canaries.

Gray-Cheeked Parakeet Mange Mites: Burrowing mites that may be found on imported Gray-Cheeked parakeets. A notable symptom is the loss of feathers on the head and neck.

Northern Fowl Mites: Outbreaks generally occur with the onset of warmer weather, and they are common in cockatiel flocks.

Fleas: Are not common on birds.

Ticks: Are found in poultry and wild birds, but not commonly on caged birds, unless they have been introduced by another pet.

Internal Parasites
Internal parasites can pose a health risk to you as well as to your pet, and they are often difficult, if not impossible, to detect except through blood tests and screenings performed by your veterinarian.

Telltale signs:

• Your bird might exhibit a sudden change in behavior.
• She might increase her vocalization.
• Her plumage may appear oily.
• There may be an increased volume of droppings, and they may appear pale or wet.
• There may be an increased appetite.
• Lesions may be present.

Air Sac Mites: May be found on Lady Gouldian finches, occasionally canaries, rarely on psittacines. There are no outward signs with a mild infestation. With heavy infestation, the bird may develop acute respiratory disease, with characteristic high-pitched clicking noises evident, sneezing, tail bobbing or open-mouth breathing. Tracheal mites may be detected in some cases.

Blood Protozoa, including Haemoproteus, Leucocytozoon, Plasmodium, and Atoxoplasma: These may be found in imported cockatoos, birds of prey and some passerines. They are uncommon in domestically raised birds. Some symptoms include hepatamegaly, splenomegaly and depression. This is usually transmitted by mosquito or biting fly.

Coccidia: Most common in gallinaceous and columbiform birds; uncommon in domestically raised birds. Some have been reported in budgerigars and finches. Symptoms may include breathing difficulties, lethargy or gastroenteritis.

Cryptospordiosis: Seen in a variety of psittacines birds and Gouldian finches. It is uncommon in domestically raised birds.

Roundworms: This is most common in parrots, but rarely in other household birds. Symptoms are weakness and emaciation. In heavy infestations, intestinal obstruction may be present.

Threadworms: Hair-like worms, found in the small intestines. Infestations result in loss of appetite, weight loss and profuse, bloody diarrhea. These are uncommon in domestically raised birds.

Tapeworms (and stomach worms): Often seen in cockatoos and African Gray parrots; uncommon in domestically raised birds. The evidence of worms many occasionally be found in the droppings or around the bird's vent. Vectors of tapeworms are insects, arachnids, earthworms and slugs. Symptoms include diarrhea and the inability to thrive.

Giardia: Most commonly found in young budgerigars and cockatiels, and occasionally in aviary finches, but only rarely seen in parrots. In cockatiels, intense feather pulling along the thighs may occur. The bird may vocalize or "complain" and oily feathers may be present. Generally, pale, wet, voluminous droppings are evident. Symptoms are lethargy, gastroenteritis, unthriftyness and difficulty breathing. In budgerigars, watch for an increased appetite and anorexia, leading to emaciation and death.

Trichomononas: Occasionally seen in canaries, finches, budgerigars and in young Amazon parrots. They are uncommon in domestically raised birds. Symptoms may include white-yellow lesions adhering to the crop and esophagus; the bird may have weight loss and difficulty swallowing, as well as difficulty breathing.

Filarid Nematodes: Found in imported birds, they are also uncommon in domestically raised birds. These affect the feet, air sacs, body cavity and connective tissue. There are no outward clinical signs for most birds; however, in South American species, there may be some swelling of the feet.

Flukes: May be found on the surface of eyes, in proventriculus, small intestine, liver, gall bladder, kidney or blood vessels. Caged birds are rarely infected; these are more common in aviaries.

Remember, if you see or suspect any of these parasites, immediately see your avian veterinarian for diagnosis and treatment.