I took my dog to the vet yesterday to get his flea treatment and mentioned he seems to be itchy on his belly area where there seemed to be faint white lumps, the vet had a look and said some long name and said its a fungal infection of his hair folicles.  He has given him 2 weeks of antibiotics and said he may need more. 

Does anyone know how he could have picked up this fungal infection, I was a bit set aback and forgot to ask the vet.