Allergic Pneumonitis (PIE) Syndrome is rather common in Beagles and is believed to have many causes. Rather than it being defined as a single disease, it is considered to be a manifestation of several different diseases. It is a subacute or chronic allergic inflammation of the small bronchioles and alveoli within the lungs and is also associated with increased numbers of eosinophils in the blood (profound eosinophilia). In Beagles, most cases are idiopathic (of unknown cause) but are more than likely associated with inhalant allergens or an infestation of heartworm.
Characteristic findings on chest x-rays and by the presence of eosinophilia and large numbers of eosinophins in a tracheal wash. Diagnosis in heartworm-endemic areas should be directed at identifying an underlying heartworm infestation. Periodically, the condition may be linked to certain environmental allergens. In these cases it is best to relocate the Beagle to a new environment or to change his existing environment to minimize exposure to the allergen. However, in most cases, the cause is unknown and environmental control is not practical.
Corticosteroids for several weeks or more usually provides a rapid resolution of clinical signs. After treatment, the disease usually will not recur.