Fleas
Resistant to many pesticides.
Source of tapeworms and cause allergic skin disease.

Intestinal Parasites
Far more prevalent in household dogs than thought.
Commonly picked up from rabbit droppings, dog parks, beaches and trails.
Some are transmissible to humans by close contact.

Heartworm Disease
Endemic, not epidemic, in local area.
Transmitted by mosquitoes.
Easily and safely prevented. Difficult and risky to treat.