PHOTO: AFPMB/Flickr
Anna O'Brien
July 24, 2017

Last month we talked about fly control in livestock. However, that’s not the end of the summer bug woes. Today, let’s give another tiny but terrible pest their due: mosquitoes and the subject of mosquito control.

Who hasn’t had a lovely summer evening ruined by the arrival of hungry mosquitoes at dusk? These bloodthirsty bugs are more than just a nuisance, leaving itchy welts on those they bite. They are serious spreaders of zoonotic disease. While ruminants such as cattle, sheep and goats can be bitten by mosquitoes, it’s the horses on the farm that have the greater threat of disease from these insects. A great incentive for mosquito control arrived in the U.S. in 1999 in the form of West Nile Virus. This meant that horse owners had increasing worries about mosquitoes around the farm—not just for themselves, but for their equine livestock as well.

A trio of encephalitis-causing viruses are also spread to horses via mosquitoes. Eastern, Western, and Venezuelan Equine Encephalitis are serious neurological diseases with occasional outbreaks. However, there is good news: There are vaccines for all four of these diseases, and horse owners are strongly advised to keep their horses’ immunization up to date.

Other than spreading diseases, mosquitoes can also cause insect hypersensitivity reactions in some horses. This typically means itchy bumps or welts. For these reasons, mosquito control in the barn in the summer is key.

First things first: Mosquitoes lay their eggs in standing water. Doing your best to eliminate standing water on your property will help decrease the amount of breeding real estate these insects have at hand and so is a good step toward mosquito control. The clue here is that you have to look hard—standing water might be hiding. This means not only low areas where the drainage is poor, but also examining any objects like old tires or barrels that might hold some residual water after a rain. Keeping water troughs and buckets clean and filled with fresh water also helps eliminate these potential breeding areas.

Given the deadly diseases they spread, mosquitoes themselves are very light and delicate. Any sort of steady breeze helps decrease their ability to land on an animal—or you—and take a bite, so increasing air circulation in a barn can be an effective measure of mosquito control. If animals are housed in the barn, fans are a great way to increase air turbulence. Lightweight fly sheets are another method for protecting a horse’s sensitive skin from biting insects of many types.

One word about bats: Yes, these flying mammals are awesome and do help gobble up some mosquitoes, but they shouldn’t be relied on for comprehensive mosquito control. Many bat species consume several types of flying insects, with mosquitoes being a small portion of what they dine on at night. That being said, a few bat houses on your property is never a bad idea.


Next Up