Not much other than advise against it and offer the details of local or breed rescues who might be able to help.
Some people just don't think do they? Thing is the next home will probably be this dog's third, if she is getting shot because of allergies, she can't have had him long and she says he is 10 months old, so he must have been somewhere else before they got him
They're getting rid because he's 'hyper' apparently - not sure exactly what they expected from a pup of that age, they're not exactly sedate as a rule! I think it's the friend who can't take him because of allergies.