The clinical signs of low grade or chronic Chlamydiosis are :-
- Progressive weight loss
- Greenish diarrhoea
- Convulsion and tremors
- Poor fertility
In untreated, acute Chlamydiosis is often fatal. If the bird is severely affected it may die despite treatment. It is seen in all species of birds. It is very common in most parrot species and in pigeons. Many birds are asymptomatic carriers. They will often only show clinical signs if stressed (e.g. new surroundings, moulting or breeding).
Chlamydia is hard to conclusively identify in the live bird. Helpful hints are the clinical signs, antigen tests (such as the Clearview Chlamydia test), cytology and blood tests. In aviary outbreaks, laboratories can do cytology or a culture on the liver, spleen, airsacs, lungs and kidneys of specimens from dead birds.