When a cat's lungs begin to calcify (a buildup of the mineral calcium in the soft tissue) or ossify (connective tissues, such as cartilage, are turned to bone or bone-like tissue) it is referred to as pulmonary mineralization.
This condition generally affects older cats and it may be generalized or localized. But if the mineralization is discrete, meaning that it is in only one place, individual mineral deposits can be identified. If mineralization is diffuse, however, it will spread out to more than one location, making it impossible to identify the individual deposits.
Pulmonary mineralization can affect both dogs and cats. If you would like to learn how this disease affects dogs, please visit this page in the PetMD health library.
Cats with pulmonary mineralization may display no symptoms at all. However, some signs or symptoms that may be observed include:
Calcification can be dystrophic (degenerative), which occurs secondary to tissue degeneration or inflammation, or it can be metastatic (transmissible throughout the body), which occurs secondary to metabolic disease, affecting the breakdown of food and its transformation into energy.
Calcification may also be considered a normal part of the aging process, or with particular breeds (e.g., premature calcification of the tracheal and bronchial cartilages in chondrodystrophic [dwarf] breeds). Calcification is often associated with a wound, thus most focal calcifications are functionally unimportant.
Ossification, also called heterotopic bone formation (the abnormal formation of true bone within extraskeletal soft tissues), can take different forms: calcification of a bony matrix (formative tissue), and pulmonary ossification in the form of small, multiple nodules.
Generalized pulmonary mineralizations of unknown cause are reported in cats under these descriptive terms: pulmonary alveolar microlithiasis or pumice stone lung; bronchiolar microlithiasis; idiopathic pulmonary calcification; or idiopathic pulmonary ossification.
The underlying cause for pulmonary fibrosis is usually unknown (idiopathic). However, it may be also due to:
Your veterinarian will conduct a full physical examination on the cat, including a chemical blood profile, complete blood count, and a urinalysis. Your veterinarian will conduct a lung biopsy to retrieve samples of tissue from your cat’s lungs in order to determine whether mineralization is occurring. Testing for the presence of bacteria and fungus will also be done.
Other diagnostic tools include chest X-rays and a computed tomography (CT) scan, so that your veterinarian can get a better look at the condition of the lungs and lymph nodes. These tools will also help confirm or exclude the presence of a tumor or fungal infection.
The formation of fibers in the walls of the alveoli
The number of respirations per minute; one respiration equals an inhalation and exhalation
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
Pertaining to the lungs
The production of bone
Relating to a disease of unknown origin, which may or may not have arisen spontaneously
Small structures that filter out the lymph and store lymphocytes
The process of removing tissue to examine it, usually for medical reasons.