The Deadliest Insect on Planet Earth

I didn't forget my blog. I left the influenza post up a bit longer because I kept getting questions from folks about it.

We've had a TON of rain here lately and thanks to that, we've had a TON of mosquitoes. You may or not be aware, but the mosquito is considered the most deadly insect on Earth. Specifically, the female anopheles mosquito because she carries malaria. But there are many other genus of mosquitoes that are quite capable of transmitting other diseases as well.

Now, to be fair, the mosquito is not inherently evil. Annoying, itchy, and somewhat disgusting to look at, but the same could be said about so many of us from time to time. Mosquitoes get the bad wrap on this one because they are blood feeders and they feed on multiple hosts over the course of their lives. This means that they, in essence, swap blood from one individual to another.

Certain parasites have taken advantage of this biological fact. Malaria organisms hitch a ride with mosquitoes and infect another person via the mosquito saliva in an infected bite. Heartworm is another example. Larva are picked up with a blood meal, molt twice in the mosquito, and then infect the next animal through the bite wound from the mosquito. Most viruses can't hitch a ride with mosquitoes, but there are some notable exceptions - mainly West Nile Virus and the equine encephalitis viruses.


Different mosquitoes have different preferences in what they feed on. Some only feed on birds, for instance. Others will freely feed on anyone including dogs, cats, people, and horses. The feeding habits of a mosquito will decide what kind of threat that particular buggar represents.

I will often see outdoor cats with little crusted bumps on the ears and upper nose, and similar areas on dogs where the ears fold over or on the bridge of the nose. These can be little bites from mosquitoes or flies and may be an indication that repellent would be appropriate.

How to protect you and your pet:

Avoidance. Mosquitoes are active near dusk and dawn. They don't like to be out in direct sunlight and don't like high winds. If you are having a hard time with mosquitoes (like we are lately), then avoid keeping your dogs and cats out during that time.

The second line of defence will be repellents. There are fewer repellent options for dogs than there are for people. Any permethryn containing product will likely be repellent to mosquitoes. Bayer's Advantix and the Vectra 3D are examples of products that have "repels mosquitoes" on the label. I've also had folks tell me they've had good luck with the Avon Skin-so-Soft products. Spray a wipe and then wipe the fur of the dog, specifically getting the tips of the ears. In theory DEET should work, but I just don't think DEET is safe. You must wash it off and that makes it impractical for most owners on a day-to-day basis.

DON'T FORGET YOUR CATS! There are even fewer options for cats than for dogs. All of the permethryn products labeled for dogs will likely kill your cat, and that's just counter productive. There are pyrethryn products that may work, and the Skin-So-Soft trick may work. You must be more careful with all of the flea, tick, and mosquito control products in cats.

MOSQUITOES WILL GET INDOORS, TOO! Having an "Indoor only" dog or cat does NOT mean that their risk of heartworm disease is eliminated. All cats and all dogs should be on preventative year round - especially those dogs and cats living in more temperate climates.

The moral of the story is that many owners forget about mosquitoes if they are not outside being bitten. Mosquitoes happily feed on your pets and they do carry with them the potential for disease. Keep your pet current on preventatives and, if appropriate, use a safe repellent for your pet.

AMH