I have a relative who has a 14 year old unknown cross. She's a small dog and has always been kept in the backyard for 14 years of her life. I've taken Milo to play with her twice so far when he was about 6 months old. They chase each other and roll around with each other (but not as much as Milo does with other puppies). They got on well, simply put.
But now, my relatives are not letting me bring my dog over because they said if she runs a lot she will die eariler. I know that this is a concern for them as she is getting fairly old. She's never had walks, met any other dogs and is not trained.
Is it really a bad thing for their dog to play with Milo because of her age? I thought I was helping by letting her at least enjoy her almost last years of life.