Aspergillosis in Cats
Aspergillosis is an opportunistic fungal infection caused by the Aspergillus, a species of common mold found throughout the environment, including dust, straw, grass clippings, and hay. An opportunistic infection occurs when an organism which does not generally cause disease becomes an infectious agent once it has entered into an animals body. In the case of Aspergillosis, it becomes an infectious agent when the body's immune system is weakened from some other disease or illness.
There are two types of acquired Aspergillus infection: nasal and disseminated. Both types can affect cats, and while no particular breed is more prone than another, Persians show a slightly higher incidence.
Symptoms and Types
There are two types of Aspergillus infections. The first is the nasal form, where the infection is localized in the nasal passages and front sinuses. It is believed that this develops from direct nasal contact with the fungus. For example, if a cat is outside and around dust and grass clippings, the fungus may enter via the moist lining of the nose. The most commonly associated symptoms are nasal discharge and noisy breathing during inhaling.
The second type of Aspergillus infection is disseminated, meaning it is more widespread in the body, not only in the nasal area. It is not certain how this form enters the body. Disseminated aspergillosis is most commonly associated with nonspecific signs, such as lethargy, depression, vomiting, and diarrhea. Other symptoms may include protruding eyeballs.
The Aspergillus fungus is commonly found in the environment in substances such as dust, hay, and grass. As an opportunistic infection, it is only likely to infect cats with an immune system that is already in a weakened state. Cats exhibiting immunodeficiency -- an inability to produce a normal immune response -- are at higher risk, and cats with illnesses such as diabetes or feline leukemia virus (FeLV) may also be more susceptible to this infection.
Diagnostic procedures vary depending on whether the infection is based in the nasal passages or is disseminated through the body. For suspected nasal aspergillosis, analysis of nasal swabs, fungal cultures of nasal discharge, and a rhinoscopy -- inserting a small fiber-optic scope into the nose in order to examine the inside of the nose and its mucus linings -- can be expected. The symptoms for disseminated aspergillosis are mostly nonspecific and therefore more difficult to diagnose. Tests may include a urine analysis and X-rays to examine the spine.