Here is a website with the treatment of thrush... but as Vance indicated he needs to see a doctor self treatment/diagnosis is not adviced
http://www.webmd.com/oral-health/tc/thrush-treatment-overview
We don't give out medication advice here because we don't recommend self medication. A Dr needs to be seen for proper diagnosis.
what is it they use to treat thrush?
He would need to see a Dr to confirm the diagnosis and get the proper treatment.