26012 Marguerite Pkwy, Suite 0, Mission Viejo, CA 92692


Mosquitoes in Irvine: Can They Spread Neurological Illnesses?

October 17, 2019

Recently, the OC Register has reported that a number of mosquitoes in Orange County have tested positive for St. Louis Encephalitis. These mosquitoes were found in Westminster and Anaheim, which are cities in close proximity to Irvine and Mission Viejo. 

While there have been no cases of human infection yet, there isn’t quite as much information about how bug bites can affect animals. Considering how much time animals spend outside, pet owners have become rightly concerned about the new mosquitoes in their area. As an animal neurology hospital in Orange County, we want to provide all our pet parents with information about how to protect their pets from infections during this time of year! 

What is encephalitis? 

First thing’s first, it is important to understand what encephalitis is and how it affects humans and animals. Encephalitis refers to inflammation of the brain. It can be caused by viruses or bacteria. Common symptoms of mild encephalitis include: 

  • Confusion or agitation
  • Mood swings
  • Fever
  • Headache
  • Fatigue

A properly functioning immune system can usually fight off infections that cause encephalitis, but if it can’t, the patient may suffer from vomiting, seizures, or loss of consciousness. 

The virus that mosquitoes in Orange County have tested positive for is St. Louis Encephalitis. According to the CDC, the fatality rate associated with this disease increases with age. Those who are infected may show no symptoms for the first 5 to 15 days after contracting the disease and then experience dizziness, malaise, and difficulty balancing after the disease incubates. 

What are the chances of my pet being infected?

While diseases, such as St. Louis Encephalitis, West Nile, and Systemic Lupus Erythematosus, spread by mosquitoes are dangerous, they are extremely rare. Even if your dog or cat is bitten by a mosquito, it’s unlikely any of these diseases will be transmitted to them. With that being said, there are other dangers that mosquito bites pose to animals. For example, heartworm is a common parasite that can be life-threatening to dogs and it is often spread by mosquitoes. Not only that, mosquito bites can be just as painful and itchy for our animals as they are for us! 

How do I prevent my pets from getting mosquito bites?

There are many ways you can reduce the risk of your dogs or cats getting attacked by mosquitoes during this time of year! While there are no vaccines to prevent St. Louis Encephalitis from hurting your animals, there are safeguards for other diseases. Dogs can take regular medication to prevent heartworm disease and cats can get vaccines for feline distemper and leukemia.

  • Since mosquitoes breed around areas of water, you can drain pools, empty water bowls, and remove other sources of water from your home to make it less attractive to the blood-sucking insects. 
  • Installing mosquito screens on doors and windows can prevent mosquitoes from flying into your home and biting your family members. 
  • Keep your pet indoors in the evening. Mosquitoes are most active right before the sun sets, so plan your pet’s outdoor playtime accordingly!
  • Not all mosquito or insect repellents are safe to use for animals since they could accidentally lick the toxic chemicals. Instead, you can invest in an insect trap or lamp. Just make sure to position it far away from your dogs or cats. 
  • Avoid wet, marshy areas. You may want to put a hold on any outdoor activities around San Joaquin Marsh, North Lake, San Diego Creek, and William R. Mason Regional Park in Irvine until mosquito season is over!

If your pet does end up getting a mosquito bite, don’t panic! Most mosquito bites are just annoying, not deadly. Apply aloe vera and antibiotic cream to prevent infection and keep an eye on the wound for the next few days. If your pet starts acting erratically or develops a fever, you can visit the vet for a checkup. 

Our vet neurologist is located near Irvine and other South Orange County cities and he specializes in treating neurological disorders. If you fear your pet has been infected with West Nile or encephalitis, give our vet neurology center a call immediately!