Can Dogs Get West Nile Virus or Lyme Disease in Chicago?

October 25, 2021


There’s a well-known fallacy in psychology called ‘proportionality bias.’ It means that people assume that major events must be the result of equally major causes. Yet anyone who’s ever played with a set of dominoes will know how impactful the smallest nudge can be — a nudge as small as, say, a mosquito. Or a tick. 

Mosquitos and ticks can pose serious health risks to your pets, as they can carry West Nile virus and Lyme disease. With the Chicago Department of Public Health having recently identified mosquitos carrying West Nile virus in multiple northside neighborhoods, it’s worth taking a moment to make sure all the members of your family stay safe, even your furrier family members. Our walker Nathaniel will walk us through how dogs and cats can catch West Nile or Lyme disease and what symptoms to look for, then give some preventative steps so you can keep your pet safe. 

West Nile

Symptoms & Treatment

While dogs and cats can catch the West Nile virus from infected mosquitos, take comfort that contracting the virus does not usually result in serious symptoms for healthy, mature pets. However, young (a year old or less), senior, and immuno-compromised pets can be more vulnerable to contracting more severe symptoms if they contract West Nile. 

Symptoms of an infection in pets are difficulty walking, loss of appetite, abnormal movement in their legs and head, disorientation, and shaking. Essentially, if your pet is behaving as if they’re ‘drunk’ you should contact your veterinarian immediately. 

What can make West Nile very challenging for pets is that the best course of treatment is to manage symptoms while letting the virus take its course since there is no standard treatment or vaccine against it. A full recovery from the virus can take possibly months, depending on the age of your pet and the strength of their immune system. This is even more reason to keep your pet safe and take precautionary measures seriously. In the next section, we will take you through how to do just that. 

Preventing West Nile

Pets can contract West Nile from infected mosquitos, the same as humans, or from coming into contact with dead birds or squirrels. So you can diminish the risk of your pet contracting West Nile considerably by keeping them indoors during peak mosquito hours (dawn, early evening, and dusk), and keeping them away from dead birds or squirrels if you spot them while out and about. 

For the owners of outdoor cats, you may want to consider keeping them indoors for the time being if your neighborhood is identified as having West Nile-carrying mosquitos. If your cat is exploring unsupervised, you’ll never be entirely sure what they’re getting up to and what they’re interacting with. Need some help keeping them entertained during their kitty quarantine? Check out our guide to indoor cat furniture!

For further prevention, use a pet-safe pest repellent. Read the label when considering which repellent to purchase, as repellents that are safe for humans may not be safe for pets. Here is a brief list of pet-friendly products many recommend:

  • Natural Chemistry Yard & Kennel Spray
  • Vet’s Best Mosquito Repellent
  • EcoSMART Home Pest Control
  • Badger Anti-Bug Shake & Spray

As a rule of thumb, remove your pet and anything they interact with from the sprayed areas while applying insecticide indoors or outdoors, as even safe insecticide can be toxic if inhaled or ingested upon first application. Make sure to remove and wash their bowls and toys after applying repellent to the affected areas. If you’re applying insecticide outdoors, keep your pets away from those areas for the first three days at least. 

For a less intrusive method of prevention, keep an eye out for bodies of standing water around your home. These attract and provide breeding grounds for mosquitos! These can include birdbaths, gutters, buckets, small ponds, rain puddles, even bowls of water left out for dogs by well-meaning neighbors! Mosquito Dunks are an excellent solution if you want a pet- and human-friendly insecticide for standing water. These water-soluble discs contain bacteria only toxic to mosquitos, so they will affect mosquitos and only mosquitos—not fish, humans, or your curious pets.

Lyme Disease

Symptoms & Treatment

Lyme is a common disease in the upper midwest that comes from that other pet-unfriendly pest — ticks. Ticks transmit Lyme disease, or Lyme borreliosis, by hanging onto the ends of foliage, attaching to passing pets (or people!), and giving their new host tick bites. Ticks can transmit Lyme disease only after hanging onto a host for 24-48 hours, so regularly checking your pet for ticks is your first-line defense, even if they’re short-haired breeds. Lyme disease is a common virus in pets, particularly in dogs but in some cases can fatally affect the kidneys if not treated in time.

Early symptoms for Lyme disease in dogs typically include fever, lethargy, nausea and vomiting, general discomfort which can manifest as lameness (walking as if on glass), and inflammation or swelling in joints. Essentially, if your dog is behaving like they have the flu, contact your veterinarian. Cats demonstrate some different symptoms: stiff movement, swelling near the site of the bite, trouble breathing, and frequent or involuntary urination (admittedly, one resource listed “sensitivity to touch” as a symptom but I imagine many cat owners might not find that too unusual!). 

Pets are treated for Lyme disease by taking antibiotics for three to four weeks. Even after treatment is complete, some symptoms such as joint inflammation and stiffness may linger for several weeks following the end of treatment.

Preventing Lyme Disease

Keeping your pet safe from Lyme disease entails getting them vaccinated and keeping them safe from ticks. Ticks are the sole carrier and distributor of the virus, so dogs cannot transmit the virus to humans or other dogs, even if infected, except through tick bites. Make sure your dog is fully vaccinated, especially if you live in or visit the upper midwest or northwestern areas of the United States where virus-carrying ticks are most common. Vets may also prescribe sprays, ointments, or other tick-prevention products.

If you hike with your pet, keep them from wandering through tall grass or bushes as much as possible. Inspect them for ticks thoroughly at the end of the day. A fine-toothed comb and a set of tweezers are very useful for de-ticking your pet. If the tick is found crawling in your pet’s fur, then it hasn’t yet bitten, so you can more easily remove them. After removing the tick, place it in a container of rubbing alcohol, a sealed plastic bag, or otherwise dispose of it before it can infect you or anyone else!

If the tick has settled, it’s in the middle of feeding and will require more effort to remove. Grasp the tick with a set of tweezers as close to the surface of the skin as possible and pull it straight out. If you don’t have tweezers, try to put something over your hands so that the tick and its blood don’t end up infecting you! Bring your dog to your vet afterward to check for symptoms of infection.

Using the preventative steps recommended above, we hope these small changes can have major benefits for your pet! Thank you Nathaniel for that information on protecting your pet from thieves! Windy City Paws is a Fear Free Chicago dog walker and petsitter committed to providing helpful information to Chicago dog owners through its blog.