Meet Miss Molly…Molly Mosquito That Is!

Molly was born in a small pond in your neighbourhood. After spending her larval (“baby” and “toddler”) days swimming around and eating algae, she enters the pupal (“teenager”) stage of her life cycle. As she exits this stage, Molly starts to breathe the air in the neighbourhood and to think about life on her own. Eventually, like all creatures, Molly “grows up” into an adult with wings.

It’s at this stage, Molly starts to explore her surroundings, and when she is ready for her first blood meal. Molly doesn’t have to go far from her family home before she finds a suitable mammal to get a snack from – the dog next door! Molly takes some time and enjoys the sunshine and warm meal before heading on to explore the neighbourhood some more.

What Molly doesn’t realize is that the neighbours’ dog has an infection called heartworm disease that she has unwillingly and unknowingly ingested with her blood meal. While this won’t directly affect Molly herself, she is now incubating the disease. Once it matures, she will start passing it on to the other animals that she shares a meal with, I mean gets a meal from.

It will take a couple of weeks, but eventually, the larvae inside Molly will be mature enough to start being passed from her to her unwilling blood donors. Every bite that Molly takes is another chance for her to pass on the infection. Molly doesn’t know any of this and continues to go about her life getting meals when she’s hungry, laying clutches of eggs, and passing the infection along all around the neighbourhood. Unfortunately for the animals in the neighbourhood, Molly doesn’t discriminate who she gets a meal from. Soon a neighbourhood that initially only had 1 Heartworm infected dog, now has 20 infected dogs and 3 cats infected all from little ol’ Molly and all in less than 3 weeks time.

The moral of Molly’s story?
All it takes is one infected dog and one tiny little mosquito to spread heartworm disease throughout an entire neighbourhood. The Ben Franklin saying, “An ounce of prevention is worth a pound of cure” is never more evident than when dealing with Heartworm disease.

Heartworm “Technical” Information:
Heartworm disease is spread from one infected mammal to another via a bite from an infected mosquito. The heartworm larvae (Dirofilaria immitis) will moult and mature 2 – 3 times throughout its 2-week stay in the mosquito. The heartworm larvae don’t have any known effects on the host mosquito.

Once matured, the larvae make their way to the female mosquitoes tube-like mouthparts (proboscis) where they wait to be injected into the unsuspecting blood host. While the mosquito takes its blood meal, the heartworm larvae is injected under the skin where they will migrate to the bloodstream.

Eventually, the larvae will mature into adult worms (takes 6 – 7 months), growing upwards of 12 inches (30+cm), and migrating to the heart, lungs and pulmonary arteries of its host. If left untreated, the heartworm larvae will eventually kill their host.

Make sure your pet is protected from heartworm disease (and other infective parasites). Consult with your veterinarian to determine which product is right for you and your pet.

Give us a call if you have any questions or concerns about heartworm.

Written by: Kathy Raepple, ACA



Dog and cat lying down on white background

A Wonderful Option for Normal People with Typical Pets: Optimum Care Plans

We all love our pets.

Read More
See All Articles

Last updated: November 4, 2021

Dear Clients,

With recent changes to restrictions on businesses, we have made some important updates to our operating policies.


This includes vaccines, wellness exams, blood work, heartworm testing, spays and neuters, dental services, and more!


Effective August 17, 2021:


If you wish to connect with a veterinarian via message, phone or video, visit our website and follow the "Online Consultation" link.


We are OPEN with the following hours:

Monday to Friday: 8:00 am - 7:00 pm
Saturday: 9:00 am - 3:00 pm
Sunday: Closed

Thank you for your patience and understanding and we look forward to seeing you and your furry family members again!

- Your dedicated team at Park Road Veterinary Clinic