You may attempt to stain for lactate dehydrogenase (LDH) if the fungal spores are active, since LDH is an enzyme expressed by most viable cells including fungi. You can stain for LDH using nitro blue tetrazolium chloride (NBTC). But this will also stain all the viable cells within the tissue sections of your animal specimens.
Pretty much any viability dye (such as combining SYTO 9 and PI) that would be used for fungi would also label the tissue. One possibility is called "FUN 1" which has a shift from green to red in viable fungal and yeast cells, so you would do a ratiometric analysis. But I'm not aware of anyone trying it in the presence of tissue and would be very concerned about its penetrance, its signal-to-background, and any potential non-specific labeling.