So my puppy is 19 weeks old now. At 12 weeks old the vet told be that only one of his testicles has decended, and if the other one doesent he'll have to be castrated. By the time hes around 15 weeks both testicles are clearly visble to me and now hes 19 weeks i cant even see one!! Do they come and go as they please? Im real concerned by it, im looking daily for them. How big are the testicles? Should i be concerned? Any help would be really appreciated!!!