The Beagle can smell the dogs from your friend and will think that this posses a threat. You must teach you dog that this is not
the case by showing him that you are happy with this person by being joyfull and at ease with your freind .This will take a few
trial periods but he will eventually come around the treat idea is good also but how you react is what will make the differance .
The Beagle's relationship with othe dogs may be part of his early development but this can be overcome with a little training .
If this fails to do the trick . contact me .at [email protected] .