Heartworm Control Strategies from Brazil to Australia

The Heartworm Diaries: Yes, Your Dog Could Be at Risk Too.

Welcome to Feature Friday. Ever heard the word heartworm and thought, “Ugh, sounds like a parasite from a horror movie?”

You're not alone and guess what? You're not far off. It is spooky but not fictional. It’s a real-life parasite (fancy name: Dirofilaria immitis) that mosquitoes inject into dogs and cats like an unsolicited horror sequel. And get this: those tiny worms grow up, rent space in your pet’s heart and lungs, and can cause cough, fatigue to full-on heart failure even death.

Cue dramatic music.

But hold on, this post isn't just doom and gloom. It's a global safari into how different countries fight heartworm. And you, my dear pet parent or vet-to-be, get to ride shotgun.

As a vet in Nigeria, I’ve had my fair share of puzzled stares when I mention heartworm to dog owners. "But my dog sleeps indoors!" they’ll say. Or, "We don’t have that here, do we?" Oh, if I had a naira for every time I heard that.

The truth? Heartworm is global. From tropical Brazil to sunburnt Australia and yes, very possibly here in Nigeria too, it’s a sneaky enemy. So I packed my virtual suitcase and took a research trip to compare strategies from two frontlines: Brazil and Australia. The good, the bad, and the itchy. Buckle up.

Brazil: Sun, Samba… and Surprise! Heartworm’s Here Too.

Let me tell you about Lola, my friend’s mischievous terrier from Rio de Janeiro. Loves chasing waves, hates baths. Her mom didn’t give heartworm prevention because, "Well, no one at the dog park mentioned it?"

Turns out, Brazil has the mosquitoes, the tropical weather, and the perfect stage for heartworm, but barely any public campaigns. Surveys show only 37% of Brazilian dogs get prevention meds and cats? Just 20%! With a prevalence shown in a survey to be 7% in dogs (7 out of 100) and 0.9% in Cats And why?

Public education is thin, the vet community is still catching up.
Vets don’t have official national guidelines.
Owners often don’t realize it’s a threat.

Brazilian vets can only offer monthly “heartworm pills” or spot-ons (macrocyclic lactones like ivermectin) to clients but Brazil doesn’t even have the gold-standard treatment drug, melarsomine - The adult-killing drug used in the U.S. or Australia. So prevention is their only shot. And if you miss a dose? Well, Lola better start practicing deep breathing.

Lola’s vet, Dr. Souza (shoutout to fictional heroes), says it best:

"Sometimes we tell pet owners about the pills, and they look at us like we’re selling snake oil, It feels like shouting at a carnival crowd. We know heartworm is dangerous, but people don’t listen until their dog starts coughing. Even then, they ask if it’s just the flu!"

The bottom line? In Brazil, the vibes are tropical, but the awareness is tropical storm-level low.

Australia: G’day to Year-Round Protection

an infested heart with heartworm

Say g’day to Bruce, a bouncy kelpie from sunny Sydney (or maybe laid-back Perth). Like most Aussie dogs, Bruce lives life outdoors: chasing balls, splashing in creeks, and sniffing every tree in a three-block radius. But there’s one thing Bruce doesn’t mess with...

Heartworm.

Why? Because Aussies don’t play games with prevention.

Australian guidelines are clear:

Every single dog should be on year-round heartworm protection, no matter the state, no matter the season. Even in drier areas, mosquitoes love hanging around creeks, dams, and shady backyards... and they love biting pets.

The Aussie Advantage: One Jab a Year

Enter ProHeart® Australia’s one-and-done annual heartworm shot.

It’s a vet’s best friend and a pet parent’s sanity-saver.

A massive study of 228,000 dogs found:

93% of dogs who got the shot were fully protected all year
Only 27-36% of monthly pill users stayed consistently protected

That means Bruce (and buddies like him) are 4x more likely to be safe if they get the shot.

Oh and owners actually spent less per year on average!

Compliance is King

Aussie vets don’t just recommend protection, they shout it from the rooftops.

Local councils run awareness campaigns
Vets offer free or discounted annual heartworm testing
Heartworm checks are now part of routine wellness exams

What’s the Secret Sauce?

The Aussie Prevention Triangle:

Vets ask
Councils promote
Owners follow through

So Bruce? He’s covered, carefree, and heartworm-free.

Nigeria: Waiting in the Wings (Or Swamps)

A chart showing how heart worm is transmitted

Now, I’m writing this from Nigeria. You know what we have?

Mosquitoes
Humidity
A ton of stray dogs
...But little to no public talk about heartworm.

When I asked a few dog owners in my neighborhood if they’ve ever heard of heartworm, I got responses like:

"You mean those small worms in poop?"
"My dog doesn’t go out much."
"That’s oyinbo disease, abi?"

No, my people. This is a mosquito-borne menace, not a white-man wahala. Even mosquitoes that sneak through windows when NEPA carry light in the nights can infect your dog.

And here’s the kicker: We already have ivermectin in Nigeria for humans and livestock. With the right guidance, we could use it safely for dogs too! But… awareness is key.

We should learn from Brazil’s cautionary tale (don’t under-communicate) and Australia’s proactive stance (do remind everyone), Nigeria can craft its own heartworm strategy. Imagine a Nigerian dog owner waking up to a WhatsApp alert: “Heartworm Alert: Don’t skip your dog’s prevention this wet season!” Simple moves like that could save many furry lives.

Vet Toolbox 101 (Quick Cheatsheet)

Let’s break down the weapons we’ve got:

Tool	Description	Who Uses It?
Macrocyclic lactones (monthly pills or spot-ons)	Kills baby worms	Brazil, Australia, worldwide
ProHeart® Injection	One jab = 6 - 12 months' protection	Only available in Australia, US
Antigen blood test	Detects heartworm infection	Standard in Aussie vet visits
Mosquito control	Mosquito nets, repellents, avoid wetlands	Everyone (especially tropical zones)

Miss a dose? That’s a big oops. One skipped month, and your dog’s heart could become a hostel for worms.

So, What Can You Do?

Here’s your part of the story:

Pet Parent?

Ask your vet: "Is my dog protected against heartworm?"
Mark your calendar for monthly prevention or ask about annual options.
Don't wait for your dog to cough before you act.

Veterinarian or Vet Student in Nigeria?

Let’s start the conversation in clinics and classrooms.
Include heartworm talks in wellness visits.
Consider malaria campaign piggybacks: "Mosquitoes bite pets too!"

Public Health Crew?

Slip a heartworm PSA into dengue or malaria campaigns.
Start with WhatsApp: "Heartworm Alert: Don’t forget your dog’s monthly meds this rainy season!"

Golden Rules for Everyone:

Be consistent: Mosquitoes don’t take holidays. Year-round prevention matters.
Test yearly: Simple blood tests catch it early—and save lives.
Use trusted meds: Vet-approved only. Herbal remedies? Hard pass.
Teamwork wins: Vets educate. Owners protect. Public health amplifies.

Zoonotic Zinger: Can Heartworm Infect Humans Too?

While rare, some heartworm species (like Dirofilaria repens) can infect humans, causing lung nodules or skin swellings. It’s not common but when it happens, it’s often misdiagnosed as tumors. Another reason to keep pets protected: a healthy pet = a safer human.

Final Bark: Think Global, Act Local

Whether you're pet-sitting in São Paulo, hiking in Perth, or navigating traffic in Lagos, heartworm is real but totally preventable.

Let’s follow Brazil’s lesson: Don’t stay silent.

Let’s copy Australia’s energy: Make prevention a lifestyle.

And for Nigeria? Let’s start the awareness wave. Our furry friends deserve more than rice and bones, they deserve strong hearts and informed owners.

So the next time you’re shopping for kibble or googling "dog vitamins", remember this post.

And maybe send it to that aunty with five Alsatians and zero vet appointments.

Until next Friday,
Stay safe.

Stay curious.

Stay vortexy
Your Favorite Mosquito Vigilante

Check out previous post - The Story Behind the First Rabies Vaccine