| MadSci Network: Zoology |
Yes, physical difficulties notwithstanding (that is, not rendering the sexual act impossible), you can breed any male dog and any female dog when the female dog is "in heat", assuming that neither dog has been neutered. Here is a previous Mad Scientist answer to a similar question: http://www.madsci.org/posts/archives/sep99/936393054.Ev.r.html
Try the links in the MadSci Library for more information on Zoology.