It's not that a dead snake is so bad. Lets say you find a DOR (dead on road) snake and need some help IDing it. It is when you post like you did (and I'm not attacking you); Look at this snake we just killed in our yard, what kind is it? That is when people start calling for your blood.
Like I said earlier, snakes are not going to bother your puppies much. If you feel they are, bring them inside at night or put them in crates that snakes can't get into. It is not responsible to go around eradicating all wildlife that "MIGHT" harm us or our pets.
I for one, am willing to forgive you. You just need to educate your parents about how helpful snakes are in keeping down the rodent populations. Rodents will make your dogs sicker than any snake ever will! Some people who have been "taught" to be scared of snakes their whole lives can be hard to "bring to the other side". But it is possible, I have done it to my mother-in-law, and it only took about 3 years.

She still doesn't like my boas, I guess I have some more work to do!
If you are interested in learning more about local herps, you might want to bring your family to the DFW Herp Society meetings. We have one this Saturday night at UTA. Check out
www.dfwherp.org for more info, or email me
[email protected].
If nothing else, you can meet up with some people in our society who live close to you, who might be able to come and get any more snakes that find their way into your yard.
Good luck with your new education mission and I hope to see you at one of our meetings. Maybe we can help you bring your parents over to the "Dark Side"
Brian Miller