Sinus Issues (continued)

[CatladyJan]

Is the test for histoplasmosis expensive? That's a fungal infection requiring an antifungal instead of antibiotic, I realize, and, yes, we do have it around here. Could a viral infection cause the pus and blood in the discharge just as a bacterial infection would? And again, given his age and gender (males are more apt to develop it), sinus cancer is a possibility.

Just my guess, but irritation can cause blood and often a viral infection can lead to a secondary infection. If your cat has a history of this it's possible that it is Feline Herpes or calcicavirus for years.

I'm not a veterinarian, but you could ask your veterinarian more questions. I hope your cat finds some comfort.