What You Need to Know About EEE Virus & Your Pets

by Nicole Decrisantis
October 9, 2019

Eastern Equine Encephalitis (EEE) risks and more need-to-know information to protect your pets.

While the fall weather brings in warm thoughts of cool weather and pumpkin spice, it is still prime weather for mosquitos in most areas of the United States. 

The rain, pockets of humidity and early sunsets give these nuisance pests more time to wreak havoc since Mosquito-borne viral diseases are a major concern of global health and result in significant economic losses in many countries1.

A deep frost will generally eliminate any remaining mosquito population, but until then read on to learn how to minimize risk for you and your pets. Triple E for dogs, or cats, has been a low-risk for many years with very few cases are reported each year.

While you are getting ready to take in the fall foliage on a hike with your dog or sitting on the front porch with your cat, here’s what you need to know about mosquitos in order to protect your pets from Triple E and more:

1. Mosquitos like to lay eggs in standing water. They are attracted to stagnant water found in bird baths, pool covers, unchlorinated kiddie pools, but they will also take advantage of small containers like cups, container lids, and unattended water bowls.

2. They typically fly 1-1.5 miles per hour2, and some can even travel up to 7 miles to breed and spread disease between areas and animals. These behaviors are what explain the increasing spread of EEE virus and West Nile virus which are spread through the bite of an infected female mosquito.

3. The average lifespan of a female mosquito is 2-3 weeks, but they can survive up to six months in the right environment3.

4. Male mosquitos feed only on plant nectars, while females feed off blood from mammals, birds, and reptiles. Female mosquitos do this so their eggs can mature prior to laying them. If they do not acquire blood, the eggs will not be viable and hatch4.

5. In some cases, mosquito eggs can survive a drought. Receiving water after an eight- month dry period, eggs can hatch and go from larva to adults in just a week5.

6. Eastern Equine Encephalitis (EEE) has been in the news recently because of human infections, but it can also be transmitted to cats, dogs, and horses6.

7. Like with heartworm dis-eases, the prevalence of EEE is unclear. In New England for example, the prevalence of heartworm has been reported to vary between 5-25 cases per veterinary clinic annually7.

Both dis-eases are preventable by improving balance which increases resistance to all infectious dis-eases.

Mosquitos spread EEE and heartworm so work to improve your pets’ balance and decrease the number of mosquitoes around your house whenever possible to prevent problems since treatment is expensive, impacts the quality of life, and is risky.

8. Cats can also get heartworm from mosquitos, though the disease and symptoms display differently than they do in dogs8.

9. This year there is expected to be a higher than average risk of mosquito-borne disease across most of the country because of the warm fall and excess moisture9.

10. Even mosquitos not carrying disease can cause skin irritation or an allergic reaction in pets – much like traditional allergic reactions10. While not much peer-reviewed literature exists mosquito bite allergies, many incidents of reactions to mosquito bites have been widely reported by pet owners.

Eastern equine encephalitis (EEE) virus can cause illness in dogs or cats, however infection is quite rare11. Most pets that do become infected with EEE, or even West Nile virus, fully recover from infection. 

Signs of Triple E can include any one or a combination of: fever, lethargy, loss of appetite, weakness, uncoordinated movement, head pressing, circling, seizures, tremors, irritability, blindness, or coma. However, not all animals with signs of encephalitis have infections like EEE. It is imperative to seek veterinary attention if your pet exhibits any of these symptoms as definitive diagnosis requires ruling out other important diseases11.

Keeping your pet indoors during high-risk times such as early morning, dusk, and overnight is the most effective short-term solution to decreasing risk for EEE virus. In addition to this, there are a number of other steps we can take to protect our pets from mosquitos and mitigate the risk of viruses and disease. The first, and often last, line of defense is an animal’s own immune system.

A diet rich in whole foods, antioxidants and fresh components is more cost-effective over the long term than care for a chronically ill pet. The right nutrition can often yield more vitality and immune function. While the “best food” for pets is wildly debatable – the most important factor to consider is your own pet’s individuality.

For animals that spend time in an outdoor kennel or open porch, natural sprays like cedar, rose geranium, and other essential oils can be used extremely effectively, although application is required more frequently than chemical pesticides. Growing evidence indicates long term risk of chemical use on their pets or yards for both humans and pets12.

The natural options that contain essential oil blends can be extremely safe for animals and effective on pests when used properly. Cedarwood oil repels and kills mosquitos, fleas, and ticks. It can be used on pet bedding, plants and directly on pets when properly diluted. In addition, lemongrass, peppermint, and rosemary repel mosquitos when applied to animals, furniture, carpet, and bedding, but are not typically used to treat plants or outdoor areas.

Several veterinary-provided and over-the-counter medications available remain the most popular choice for pet owners and parasite and related disease prevention. Some work by repelling the insect along with fleas and ticks and others provide a low dose medication that
prevents the maturing of some mosquito-spread diseases, including heartworm.

While the options are considered generally safe for most healthy dogs, all do have risks – especially if package directions are not adhered to or these are used for ill pets13. In addition, there is additional risks when these are used in conjunction with lawn preventatives12. It is also imperative to check if your particular preventative is safe for puppies, pregnant dog, or dogs currently being bred.

Chemical yard treatments available typically involve a pesticide granule to keep mosquitos at bay. Commercial and retail treatments vary greatly in ingredients, toxicity, and application amounts. If your pet eats grass or spends enough time on the treated areas, they can ingest and absorb these chemicals through inhalation and their paw pads – and increased exposure to pesticides has been linked to allergy, inflammation or nervous system complications in both pets and people.

For optimal Vitality and health of your pet, always use these chemical products cautiously, sparingly and never mix commercial products. Take time to read the ingredients and directions before applying any chemicals, and watch for adverse effects. In fact, many treatments prohibit animal contact until the application is dry or for 1-7 days in some instances.

With so many options to manage the risks of mosquitos and other insects, making the best choice for your animals can be stressful. Having a trusted holistic veterinary advisor will help decrease this anxiety of uncertainty.

Use of prescriptions, store-bought options, natural treatments or a combination are up to you and depend on your animal’s health, lifestyle, and location14. An animal that spends more time by water or woods may require a different strategy then a dog living in a city apartment or a cat that is strictly indoors. It is best to research your options and discuss them with a trusted veterinarian.

It is also vital to review their diet regularly and get annual testing for heartworm and other insect-borne diseases. If you notice any changes in your pets’ BEAM (Behavior, Energy, Appetite Mood) that may suggest they are under the weather, do not delay in seeking vet treatment!

Proactive preventative health measures through lifestyle, diet and other preventative strategies are always more effective than reactive treatment.

This entry is offered for informational purposes only and should not replace the advice from a qualified veterinarian. Be sure to discuss all concerns with your veterinarian in order to help all involved make an informed decision when it comes to the care of your pets.

1. Cheng G, Liu Y, Wang P, Xiao X. Mosquito Defense Strategies against Viral Infection. Trends Parasitol. 2016;32(3):177-186. doi:10.1016/j.pt.2015.09.009

2. FAQ – American Mosquito Control Association. FAQ – American Mosquito Control Association. Accessed September 30, 2019.

3. Mosquito Lifespan: How Long Do Mosquitoes Live? (From Egg To Death). End Mosquitoes. Mosquito Lifespan: How Long Do Mosquitoes Live? (From Egg To Death). Published December 25, 2018. Accessed October 1, 2019.

4. User S. Jackson Township – Mosquitoes. Jackson Township – Mosquitoes. Accessed September 30, 2019.

5. Zika, Mosquitoes, and Standing Water | | Blogs | CDC. Zika, Mosquitoes, and Standing Water | | Blogs | CDC. Accessed September 30, 2019.

6. Symptoms & Treatment | Eastern Equine Encephalitis | CDC. Symptoms & Treatment | Eastern Equine Encephalitis | CDC. Published May 22, 2019. Accessed September 30, 2019.

7. Incidence Maps – American Heartworm Society. https://www.heartwormsociety.org/veterinary-resources/client-education/incidence- maps. Accessed September 30, 2019.

8. Heartworm in Cats – American Heartworm Society. Heartworm in Cats – American Heartworm Society. Accessed September 30, 2019.

9. What mosquito-borne and tick-borne infections are threatening your pet in 2019? | Pets & Parasites: The Pet Owner’s Parasite Resource. https://www.petsandparasites.org/expert- insights/2019forecasts/. Accessed September 30, 2019.

10. Insect Bite Reaction in Dogs. vca_corporate. vcahospitals.com/know-your-pet/insect-bite- reaction-in-dogs. Accessed September 30, 2019.
11. WNV and EEE in Animals. Mass.gov. https://www.mass.gov/service-details/wnv-and-eee- in-animals. Accessed October 1, 2019.

12. Protect Your Pets From Dangerous Lawn Chemicals | Midwest Pesticide Action Center. Protect Your Pets From Dangerous Lawn Chemicals | Midwest Pesticide Action Center. Accessed October 4, 2019.

13. US EPA O. EPA Evaluation of Pet Spot-on Products: Analysis and Plans for Reducing Harmful Effects. US EPA. https://www.epa.gov/pets/epa-evaluation-pet-spot-products- analysis-and-plans-reducing-harmful-effects. Published March 27, 2013. Accessed September 30, 2019.

14. Dr. Jeffrey Levy DVM PCH :: Classical Veterinary Homeopathy : Heartworm. https://www.homeovet.net/content/lifestyle/section4.html. Accessed September 30, 2019.