[York Lover]

I have a 3 year old male Yorkie. Three months ago I took him to the vet because he had a creamy discharge coming out of his penis. They aid that it was a sheath infection and gave me some cream to treat it. It went away and now it is back. Could it be something else or why would he be getting this infection again? He doesn't hump things and he is not fixed. Could he just be ready to breed? Please help if you have any info. Thank you!!