[anguish]

I just can't imagine a Saint Bernard and a chihuahua

I think it's a sign of good mental health not being able to imagine that :p ... However, they can still interbreed and indeed create fertile offspring, even if the 'act' itself has become somewhat cumbersome due to the enormous difference in size.

The various dog breeds we have are very recent, from a evolutionary perspective, so they have yet to speciate. Given enough time I don't think many biologists would disagree that the Saint Berhard and Chihuahua are likely subjects for speciation though :)

[wai-ming]

However, they can still interbreed and indeed create fertile offspring, even if the 'act' itself has become somewhat cumbersome due to the enormous difference in size.

That is amazing. I learn something new every day!

Thanks for the information.

[PatrickHenry]

However, they [Saint Bernard and a chihuahua] can still interbreed and indeed create fertile offspring, even if the 'act' itself has become somewhat cumbersome due to the enormous difference in size.

I've read that it's only possible if the female is the St. Bernard. She's large enough to produce live offspring. But a female chihuahua, assuming she somehow survives an encounter with a male St. Bernard, isn't be large enough to drop the resulting litter. Otherwise, I think that at the genetic level the mating is no problem at all.