My Pine Tree is sick; Is it fungus?

I first noticed the pine needles on the small (dwarf) 30-year old pine tree in front of my house have been turning brown.  I trimmed the brown needles hoping that new growth would be healthy.   It did not help as can be seen in the photos. I speculate that the problem may be due to the excessive rainfall we have had, which caused the roots to rot, or it may be some fungus.    I know little about trees, and I am afraid I have waited too long to ask for help here.  The local tree expert co has not been returning calls for this type of work.  

Should I use a fungicide?  I will be grateful for any suggestions.

The disease is diplodia.  Too late to treat it now.  Has to be treated in the spring when the new needles are being formed.

Thank you very much quercus.  I'll treat it in the Spring.