But when he is with her dog Roscoe, something remarkable happens - the speech that is so hard to get out normally suddenly becomes easy, as the father chats away to the animal.
Watch the incredible interaction between Lisa's father and this happy pup here.
As the dog comes over and allows himself to be petted, he hands the man what looks like a piece of bone and starts chewing on it.
'Oh yeah, hey! You've got something. You've got something! Huh?' says Lisa's father, who usually struggles to get words out.
As the dog wags his tail enthusiastically, the old man continues: 'Yeah, well, that, that's too bad, there. That's all. That's all I've got. Why don't I take care. I'll take you. And you take me.'
The man can then be seen rubbing the dog's belly, as the video maker urges watchers to appreciate their parents before it's too late, writing: 'If your parents can still talk to you, please listen. You never know when it will be the last time.'
Have you had a similar experience with an animal being able to bring an ill or injured person out of themselves? Tell us your experience below.