Although morally reprehensible, dogs and humans can mate. However, no pregnancy can result from their copulation.
Human DNA and canine DNA are so vastly different that pregnancy between the two species is impossible. Human DNA and canine DNA are unique and composed of different numbers of chromosomes.
It's important to note that zoophilia is a felony in some states and a misdemeanor in others. Although it is referred to by different charges, ranging from bestiality to "crimes against nature" and criminal sodomy, the act is the same. If convicted, those committing these crimes can receive up to six years in prison, fines of up to $25,000 or more and a life-long criminal record noting their deviant history.