Knowing the life cycle of heartworms can help you determine the best way to treat your pack.
http://healthydogs.org/2005/12/heartworm_meds.htmlAnd for the hay of it here is another link which suggest that the popular, mainstream information is false(at best).
vaccination fraud by con artist vets:
http://www.freewebs.com/christyice/vaccinationinfo.htmthe truth about spay and neuter:
http://www.caninesports.com/SNBehaviorBoneDataSnapShot.pdf