Tech entrepreneur Bryan Johnson has become famous for his mission to help humans live forever, with his catchphrase “Don’t die.” Now he wants to do the same thing for dogs.

Johnson’s interest in canine longevity was piqued when he recently adopted a professionally trained Belgian Malinois named Katara to protect him from attackers.

This week, at a longevity event in San Francisco, Katara was a constant presence at Johnson’s side as he cheered on tech workers trying to complete as many push-ups as possible, one metric used to measure their biological age. Later, Katara, who will turn two in October, lay patiently at Johnson’s feet as he was…