Page 668 - The Veterinary Care of the Horse
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Figure 15.9 This horse with sinusitis has a persistent, thick yellow discharge from one nostril
Diagnosis
Diagnosis is usually straightforward. The history is often suggestive of sinusitis and the
diagnosis is confirmed by radiography and endoscopy.
RADIOGRAPHY
The sinuses of normal horses are filled with air and appear black on radiographs. If there is
an accumulation of liquid pus within the sinus, an obvious horizontal line can be seen. This is
because the pus is denser than air and looks grey. Soft tissue masses such as mucus-filled
