Millie is on Heat

[harm_less]

Where did you get 40 in human years?? Nonsense.

As a general guideline, though, the American Veterinary Medical Association breaks it down like this:

    15 human years equals the first year of a medium-sized dog's life.
    Year two for a dog equals about nine years for a human.
    And after that, each human year would be approximately five years for a dog.

So, that makes this 8yo dog 54yo in human years.  Even if possible still, at least a 54 yo woman has a choice. A dog doesn't. Unless they have selfish owners, who are potentially putting their dog at risk of all sorts of complications.

That would only work if humans expected to live until they were 108, which is rare rather than common. 8 for a Jack is mid life (one would expect a Jack to get to 16 years easily). So no where near your 54 years. For a Rotty 8 would be near expiry. An 8 year old bitch on a 3rd litter should be no problem at all. The complications thereafter depend on litter size, food supply etc.

That was my logic in the 40 YO human equivalency. Life expectancy for our species is around 80 in most first world countries.