Page 733 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

708 CHAPTER 3

VetBooks.ir 3.168 Fig. 3.168 Thoracic radiograph of a
horse with granulomatous pneumonia.
Multifocal opacities are visible
throughout the lung field.

Fig. 3.169 Aspergillus granuloma
in the lungs of a horse with fungal
pneumonia (20× magnification).
(Photo courtesy Kaori Sakamoto)

are non- specific. Mild suppurative inflammation
3.169
may be present. Lung biopsy is required for diag-
nosis. Sampling of the nodular masses is optimised
by ultrasound-guided lung biopsy. Histopathology
reveals non-caseating granulomas affiliated with
bronchi and bronchioles (Fig. 3.169). Intracellular
crystalline material may be observed in silicosis.
Efforts to elucidate a cause should include serum
immunodiffusion testing for antibodies against
Coccidioides immitis, selective histopathological stain-
ing of lung tissue for fungal and mycobacterial
agents and bacterial and fungal culture of tracheal
aspirate or BAL fluids.

Management
nasal discharge and abnormal lung sounds. Clinical Adequate target therapy cannot be prescribed since
signs do not respond to antibiotic therapy and NSAIDs. the cause remains unknown. Corticosteroids are
widely used in these cases, but there is no informa-
Differential diagnoses tion supporting their efficacy.
Fungal, parasitic or bacterial pneumonia and pulmo-
nary neoplasia should be considered. Prognosis
The prognosis is poor because of the lack of a proven
Diagnosis treatment. Affected horses are commonly euthana-
For disease caused by silicate pneumoconiosis or sed because of progressive and severe debilitation
coccidioidomycosis, the geographical origin of associated with the disease.
the horse from an endemic area may be sugges-
tive. Haematological testing is indicated and evi- SMOKE INHALATION
dence of a chronic inflammatory process (anaemia,
neutrophilia, hyperfibrinogenaemia and increased Definition/overview
globulins) is often present. Thoracic radiographs Smoke inhalation is a clinical syndrome that occurs
are very important (Fig. 3.168). A miliary or nod- as a result of inhalation of harmful gases, vapours
ular interstitial pattern may be present through- and/or particulate matter contained in smoke,
out the lung. Tracheal aspirate and BAL cytology usually originating from barn fires (Fig. 3.170).