Mosquitoes just need a bit of water for reproduction. Even in dry, desert-like climates, like Las Vegas, they’ve found ways to use human activity to help them reproduce in hotel fountains or suburban retention ponds (mosquitoes need to lay eggs in water, so even rivers, ponds, puddles, or bird feeders will suffice). The pesky critters are everywhere, and they are hardly benign. They spread diseases to us and can deliver potentially deadly heartworm to dogs.
Experts are now suggesting for dogs what they’ve been recommending for people for many years: a multimodal or “Double-Defense” approach. In addition to using a traditional heartworm preventive (ask your veterinarian for the right product for your pet), Vectra 3D provides additional defense, and at the same time also protects against fleas and ticks (which you ought to be doing with a product anyway).