As noted everyone is saying that longevity is a multifactor situation. Detailed records are important and it is as much about the Bitch as the Stud.
The issue I see in figuring it out also has to take into account how the dogs are kept. High stress environments, poor diet, over weight, poor situations for growth and so forth all contribute to longevity (or lack thereof). Conformation is also a huge factor.
When a person breeds dogs they have many things to consider beyond health testing and titles. The dogs also need to have sound conformation, a family line that shows sound conformation in the past, sound temperament (which can actually outweigh some conformation flaws), health tests and so forth. In the German Shepherd, bitches should be bred after 2 but by age 3 and a half due to concerns about breeding at all ("catching") and concerns about Pyometra.. and, most bitches are retired and spayed by age 7 and a half.. often with only producing 3.. MAYBE 4 litters. Studs can go longer but sperm counts often decrease with age. Any issues of longevity in the bitch and the stud usually show up AFTER litters have been produced, so "knowing" about longevity may not happen until the second generation.
Of course, is some breeds there are chronic issues such as ACL tears and cancer and those entire lines are often culled when the issues becomes chronic throughout those lines and litters.
The last issue is the longevity of the breeder. A LOT of people out there have nice dogs, do all the testing, produce a litter or two and realize the awful money pit breeding can be and leave the breeder arena. The dogs they produce may be breeding worthy and someone who gets one may do the same thing.. so there is a lack of continuity of records other than health tests and titles.
Then we get into the whole thing of shelter and rescue dogs.. that may live for 2 years or 15 years and you have no idea what and where the genes came from.
The issue I see in figuring it out also has to take into account how the dogs are kept. High stress environments, poor diet, over weight, poor situations for growth and so forth all contribute to longevity (or lack thereof). Conformation is also a huge factor.
When a person breeds dogs they have many things to consider beyond health testing and titles. The dogs also need to have sound conformation, a family line that shows sound conformation in the past, sound temperament (which can actually outweigh some conformation flaws), health tests and so forth. In the German Shepherd, bitches should be bred after 2 but by age 3 and a half due to concerns about breeding at all ("catching") and concerns about Pyometra.. and, most bitches are retired and spayed by age 7 and a half.. often with only producing 3.. MAYBE 4 litters. Studs can go longer but sperm counts often decrease with age. Any issues of longevity in the bitch and the stud usually show up AFTER litters have been produced, so "knowing" about longevity may not happen until the second generation.
Of course, is some breeds there are chronic issues such as ACL tears and cancer and those entire lines are often culled when the issues becomes chronic throughout those lines and litters.
The last issue is the longevity of the breeder. A LOT of people out there have nice dogs, do all the testing, produce a litter or two and realize the awful money pit breeding can be and leave the breeder arena. The dogs they produce may be breeding worthy and someone who gets one may do the same thing.. so there is a lack of continuity of records other than health tests and titles.
Then we get into the whole thing of shelter and rescue dogs.. that may live for 2 years or 15 years and you have no idea what and where the genes came from.
