Bacterial diseases:

Pasteurellosis

Staphylococcus sp. infection

Bordetella sp.

Pseudomonas sp.

Chlamydiosis

Mycoplasma sp.

Presence of abscesses in the lungs

Bacterial pneumonia

 Fungal diseases:

Mycobacterium sp.

Aspergillus sp.

 Metabolic diseases:

Hypothyroidism

Metabolic alkalosis (Alkalosis of the lungs may be caused by too much air coming into the lungs (hyperventilation).

 Mechanical problems:

Aspiration of a foreign body, like a piece of hay

Lung injury or trauma

Extensive pulmonary hemorrhages

Tumors or vascular abnormalities involving the brain stem

 Central nervous system diseases:

Neuromuscular disease

Disorders of the peripheral nervous system

 Neoplastic diseases:

Abdominal mass (e.g. thymoma)

Lung metastasis

Presence of a tumor in the trachea

Cardiac diseases:

Presence of a pulmonary edema

Chronic cardiovascular diseases

Congestive heart failure

Autoimmune or chemically induced

Allergy

Ammonia vapors

Anaphylaxis

Toxins

Overdosage of a sedative or anesthetic drug