Synonyms

Allergic extrinsic alveolitis (chronic form)

Name of the disease in English

Chronic bovine farmer's lung; Extrinsic allergic alveolitis

The disease in brief

This is a pulmonary hypersensitivity (Arthus phenomenon = HS III due to inhaled antigens) to chronic inhalation of microorganisms, most often thermophilic actinomycetes contained in moldy or dusty hay, straw or cereals. The disease occurs in cattle in the stable in contact with these antigens. Chronic exposure creates the chronic form of the disease.

Clinic & diagnosis

A bovine presenting with expiratory dyspnea (difficult or forced expiration), with a normal respiratory sound on auscultation and a slow and progressive deterioration of the general condition may be suspected of the disease if it is in contact with moldy or dusty hay, straw or cereals; one may also notice a recurrence of symptoms in the stable and an improvement outside.

Typical sign of the disease

No description

Pictures

See below

Diagnostic formulas

No description

Differential diagnosis

- Chronic healed-consolidated bronchopneumonia RS24.3

-Bronchopneumonia-Emphysema virus RS RS26.2

-Recovery emphysema - subacute to chronic form RS28.1

Confirm a suspicion?

There is no easy way to confirm; remove the cattle from the mold and see if the problem improves significantly.

Prognosis and treatment

The treatment consists of removing the cattle from the dusty atmosphere of the stables and especially from moldy fodder.

Prevention

-Control the drying of hay; if hay becomes moldy by accident, do not distribute it in poorly ventilated stables, and do not put it in racks raised above the cattle.
-Review the ventilation of the stables.

References

Veterinary Medicine-Pocket companion -9th Edition BLOOD DC-page 668