How long did dogs live20- 50 years ago?

nowadays it is 10-15 years. What about 20, 30 or 50 years ago when veterinary medicine was not advanced or when dogs were not considered as companions.

20, 30 or 50 human years, or dog years?

Sailboat

The really dramatic advance in life span has been seen with cats. Older veterinarians talk about 8 years of age being a common “upper limit” while today it is considered early middle age. I routinely see cats in their late teens/early twenties today.