Birth mass is the key to understanding the negative correlation between lifespan and body size in dogs
Figure 2.Calculated cellular damage increases as a function of age in two dog breeds. (physiological parameters in Eq. 1 required to produce this figure: B0 = 3158 Joules/(day.gram0.69) [7,8], Em = 5000 Joules/gram, and ε = 0.999) [34,40,53]. The solid and dashed arrows indicate the ages at which ~ 90% of the adult masses are reached in two dog breeds. These ages were estimated from the growth equation, Emdm/dt=Brest-Bmaint and the birth and adult masses of both dog breeds.