Think 12 is an ongoing initiative through which the American Heartworm Society provides educational materials, including articles, fact sheets, posters, videos and other tools that help pet owners understand the need to administer heartworm preventives 12 months a year and test pets for heartworm every 12 months. Year-round prevention and annual testing are recommended by American Heartworm Society, and form the foundation of their guidelines for heartworm prevention and diagnosis.
New Think 12 materials and tools are produced each month, and are made available to veterinary professionals and pet owners free of charge. Think 12 materials can be downloaded and displayed, printed as handouts—or used in clinic newsletters or on social media platforms. Check the Think 12 Resource Center frequently for new materials or browse through our archives for educational tools on the topic of your choice.
Prevention all year long
There is no "off-season" for heartworm prevention and treatment. The handouts below make perfect value-added conversation starters with clients and prospective patients. Feel free to print and distribute in your practice.
Why Your Dog Needs an Annual Heartworm Check-up
Category: Fact SheetsCanine | Prevention | Diagnosis
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5 Facts About Heartworm Disease
Category: Fact SheetsCanine | Feline | Prevention | Diagnosis | Treatment | Exotics
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What if My Dog Tests Positive for Heartworms
The news that a dog has tested positive for heartworms can be scary for a dog owner. This fact sheet outline what to expect during treatment and how to ensure your pet stays heartworm-free in the future.
Category: Fact SheetsCanine | Prevention | Diagnosis | Treatment | Shelters | Veterinary Professionals | Pet Owners
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Your walls will talk
Our beautiful new set of posters make a strong impression. Click on any poster thumbnail below to access a high-resolution version that you are invited to print or share.
Click an image below to see a full-resolution version. You may then save the image by right-clicking (PC) or CTRL + Click (Mac) and choosing "Save image" from the popup menu.
Pet Owner Education Posters
These are Heartworms (Spanish)
A picture paints a thousand words in this poster showing what heartworms look like.
Category: Pet Owner Education PostersCanine | Prevention | Treatment | Shelters | Veterinary Professionals | Pet Owners
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The Masked Marauder
If pets are unprotected, they're in danger from mosquitoes that transmit heartworms.
Category: Pet Owner Education PostersCanine | Feline | Prevention | Exotics | Other | Veterinary Professionals | Pet Owners
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Don't let heartworm disease break your heart (empty collar)
Heartworm disease can be fatal in dogs. See your veterinarian for annual testing and year-round prevention.
Category: Pet Owner Education PostersCanine | Feline | Prevention | Veterinary Professionals | Pet Owners
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These are heartworms
One mosquito bite can lead to heartworms that are 12 inches long--or more.
Category: Pet Owner Education PostersCanine | Feline | Prevention | Diagnosis | Exotics | Other | Veterinary Professionals | Pet Owners
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Don’t let heartworm disease break your heart (dog house)
Heartworm disease can be fatal in dogs. Make sure to have your veterinarian prescribe heartworm prevention.
Category: Pet Owner Education PostersCanine | Prevention | Veterinary Professionals | Pet Owners
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Grounded/Unfounded Series
Grounded or Unfounded: Heartworm disease in dogs is difficult to treat.
While hearworm infection can be treated in dogs, the treatment regime can be arduous.
Category: Grounded/Unfounded Series PostersCanine | Prevention | Treatment | Veterinary Professionals | Pet Owners
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Grounded or Unfounded: Treating for ticks and fleas does not protect my dog from heartworm infection.
Not every parasite-prevention product prevents heartworm in pets--some only address pests like fleas and ticks. Read the label and make sure your pet is getting the protection he or she needs.
Category: Grounded/Unfounded Series PostersCanine | Prevention | Veterinary Professionals | Pet Owners
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Grounded or Unfounded: Only dogs and cats get heartworms.
Heartworm don't just infect dogs and cats--from ferrets to foxes, a number of other species get heartworm disease, too.
Category: Grounded/Unfounded Series PostersCanine | Feline | Prevention | Diagnosis | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Grounded or Unfounded: It's too dry here for heartworms.
Mosquitoes--and heartworms--can be found in desert climates where practices like irrigation and watering provide places for mosquitoes to breed.
Category: Grounded/Unfounded Series PostersCanine | Feline | Prevention | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Grounded or Unfounded: It's too cold here for heartworms.
Many areas of the country have cold winters--AND heartworms. Year-round prevention provides the best way to keep your pet safe.
Category: Grounded/Unfounded Series PostersCanine | Feline | Prevention | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Grounded or Unfounded: Indoor pets are safe from heartworm infection.
Mosquitoes come inside--which means "indoor" pets are exposed to heartworms, too.
Category: Grounded/Unfounded Series PostersCanine | Prevention | Life Cycle | Veterinary Professionals | Pet Owners | Incidence
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Grounded or Unfounded: Heartworms don't live here.
While heartworms are more prevalent in some parts of the country they're diagnosed in all 50 states.
Category: Grounded/Unfounded Series PostersCanine | Feline | Prevention | Exotics | Other | Veterinary Professionals | Pet Owners
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Grounded or Unfounded: Dogs taking heartworm preventives should be tested every year.
Annual testing is an important component of heartworm management in dogs, even if they're on prevention.
Category: Grounded/Unfounded Series PostersCanine | Prevention | Diagnosis | Veterinary Professionals | Pet Owners
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Grounded or Unfounded: Cats don't get heartworm disease
Cats get heartworm disease, too--and unlike dogs, they have no options for treatment. Year-round prevention is the best approach.
Category: Grounded/Unfounded Series PostersFeline | Prevention | Veterinary Professionals | Pet Owners
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Grounded or Unfounded: All drugs that prevent parasites prevent heartworm infection.
Treating your pet for parasites? Read the label and make sure it covers heartworms!
Category: Grounded/Unfounded Series PostersCanine | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series
Think 12 Series: Would you know if she had heartworm (canine)
Heartworms happen on the inside. Only a veterinarian is equipped to test dog for heartworms.
Category: Think 12 PostersCanine | Prevention | Diagnosis | Veterinary Professionals | Pet Owners
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Think 12 Series: Would you know if he had heartworm (feline)
Heartworms happen on the inside. Only a veterinarian is equipped to test cats for heartworms.
Category: Think 12 PostersFeline | Prevention | Diagnosis | Veterinary Professionals | Pet Owners
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Think 12 Series: Has heartworms will travel
Coyotes get heartworms. And because they're not likely to be on heartworm prevention, they are an important source of heartworm transmission.
Category: Think 12 PostersPrevention | Other | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: If your cat gets heartworms there is no treatment
Sad but true--there's no approved treatment for heartworm infection in cats.
Category: Think 12 PostersFeline | Prevention | Treatment | Veterinary Professionals | Pet Owners
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Think 12 Series: Loves the beach. Doesn't love heartworms
What dog would want heartworms? Protect your pup!
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series: Just One infected mosquito can infect many pets
An infected mosquito can infect every pet it feeds on.
Category: Think 12 PostersCanine | Feline | Prevention | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Both indoor and outdoor cats get heartworms
Anywhere there are mosquitoes--indoors or out--there's a threat of heartworm disease for a cat.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series: Heartworms can grow up to a foot long (b)
Heartworms can grow to be 12 inches long or MORE inside a dog's heart, lungs, and arteries.
Category: Think 12 PostersCanine | Prevention | Treatment | Veterinary Professionals | Pet Owners
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Think 12 Series: Enemies Approaching
Heartworms are spread by mosquitoes--and it only takes one bite.
Category: Think 12 PostersCanine | Feline | Prevention | Life Cycle | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: She can't hide from heartworm (canine)
Your dog can't play hide-and--go-seek with heartworms. Keep him on year-round heartworm prevention.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: He can't hide from heartworm (feline)
Unprotected cats are a risk of being bitten by an infected mosquito. Keep him on preventives year-round.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: He can't hide from heartworm (ferret)
Cute little ferrets are HIGHLY susceptible to heartworms.
Category: Think 12 PostersPrevention | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Braves the outdoors. Fears Heartworms. (feline)
Cats that aren't on year-round heartworm prevention have reason to fear this sometimes fatal--disease.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Has your growing dog outgrown her heartworm preventive
Puppies grow up fast, and their heartworm medication dosage can change quickly. Make sure your dog is taking the right dose.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series: Has your big boned cat outgrown his heartworm preventive
Heartworm preventives are dosed by weight. Make sure your kitty is getting the right dose.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series: Heartworms can grow up to a foot long (a)
Heartworms are long. In fact, they can grow more than a foot long in a dog's heart, lungs and arteries.
Category: Think 12 PostersCanine | Prevention | Treatment | Veterinary Professionals | Pet Owners
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Think 12 Series: Where there's a will, there's a way for heartworms to get inside. (Dog & Cat)
Indoor pets aren't safe from heartworms.
Category: Think 12 PostersCanine | Feline | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Where there's a will, there's a way for heartworms to get inside. (Cat)
Mosquitoes are sneaky and find lots of ways to come indoors. Indoor pets need heartworm prevention, too.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: There's no such thing as a heartworm free zone. (Desert)
Heartworms have been diagnosed in all 50 states.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Protection is priceless. (Dog)
Heartworm disease can threaten your dog's health--and even his life.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners | Cost
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Think 12 Series: Protection is priceless. (Cat)
There's no approved treatment for heartworm infection in cats.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners | Cost
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Think 12 Series: Heartworms love vacations, too. (Young Owner)
Warm and sunny? Yes. Mosquitoes? Yes. Heartworm prevention? Yes.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Media | Incidence
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Think 12 Series: Heartworms love vacations, too. (Two Dogs)
When you pack for that long vacation, don't forget your dog's heartworm prevention.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Heartworms love vacations, too. (Senior Owner)
That warm, sunny vacation spot is probably a safe haven for heartworms. Make sure your dog is protected.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Heartworms are always in season. (Hunting)
Make it "open season" on heartworms by giving your dog year-round heartworm prevention.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Heartworms are always in season. (Hiking)
Cooler weather doesn't necessarily mean the threat of heartworms is gone.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Think 12 Series: Heartworm protection is spelled L-O-V-E. (Dog)
If you love your dog, protect him from heartworms.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series: Heartworm protection is spelled L-O-V-E. (Cat)
If you love your cat, protect her from heartworms.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series: Best friends deserve the best care. (Dog)
Dogs are loyal friends. Show you love them by protecting them from heartworms.
Category: Think 12 PostersCanine | Prevention | Veterinary Professionals | Pet Owners
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Think 12 Series: Best friends deserve the best care. (Cat)
Heartworm prevention helps keep cats happy and healthy.
Category: Think 12 PostersFeline | Prevention | Veterinary Professionals | Pet Owners
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Pictures worth a thousand words
The infographics below are intended to make heartworm disease and its impact easy to understand. You may download, print, and share these images and files.
"City living" infographic
This infographic shows how the "heat islands" created by buildings, concrete, vehicles and other aspects of "city living" extend the length time that mosquitoes survive--and heartworm stays a threat
Category: InfographicsCanine | Feline | Prevention | Life Cycle | Shelters | Veterinary Professionals | Pet Owners | Incidence
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Canine Heartworm Progression
This infographic show how heartworm infection infects a dog, starting from transmission through the late stages of infection.
Category: InfographicsCanine | Prevention | Diagnosis | Treatment | Life Cycle | Shelters | Veterinary Professionals | Pet Owners | Incidence
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Famous Last Words
There's lots of myths that can be perpetuated and mistakes that can be made when talking to pet owners about heartworms in pets. These are few "famous last words" your clients should NOT hear you say!
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Shelters | Veterinary Professionals | Incidence
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Do's and Don'ts of Exercise Restriction
Keeping your dog calm and quiet in the weeks before, during and after heartworm treatment is essential. Follow these recommendations to help make treatment successful and safe.
Category: InfographicsCanine | Treatment | Shelters | Veterinary Professionals | Pet Owners
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The number of heartworm-positive pets may be bigger than we think
Many dogs and cats with heartworms are undiagnosed. Here's why.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Shelters | Veterinary Professionals | Pet Owners | Incidence
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"Dog Days" of Summer
In this infographic, learn about the risks heartworm pose to dogs and cats.
Category: InfographicsCanine | Feline | Prevention | Shelters | Veterinary Professionals | Media | Pet Owners | Incidence
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AHS Incidence Survey Infographic
Heartworm was diagnosed in all 50 states in the 2022 Heartworm Incidence Survey. This infographic includes details from this survey, which was conducted with veterinarians across the U.S.
Category: InfographicsCanine | Prevention | Diagnosis | Shelters | Veterinary Professionals | Media | Pet Owners | Incidence
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How Do Cats Get Heartworms?
Like dogs, cats get heartworms through the bite of an infected mosquito. However, the disease cats get from heartworms is different from that of dogs.
Category: InfographicsFeline | Life Cycle | Shelters | Veterinary Professionals | Pet Owners | Incidence
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There's No Season for Heartworms
Heartworm transmission doesn't have a "season." That's why the AHS recommends year-round heartworm prevention.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Shelters | Veterinary Professionals | Pet Owners | Incidence
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A Stroll Through Petsville: How Heartworm Prevention Adds Up
Heartworm prevention makes sense for pet health--and saves dollars and cents for pet owners.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Shelters | Veterinary Professionals | Pet Owners | Cost
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How Do Dogs Get Heartworms?
Understanding the heartworm life cycle can help you better understand why it's important to protect your dog. This infographic makes the life cycle easy to understand.
Category: InfographicsCanine | Prevention | Diagnosis | Life Cycle | Veterinary Professionals | Pet Owners
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Myth Fact Infographic
Are you up for a heartworm quiz? This infographic tests your knowledge.
Category: InfographicsCanine | Prevention | Diagnosis | Veterinary Professionals | Pet Owners | Cost
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Pet Lovers Prioritize Pet Health During the COVID-19 Crisis
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Exotics
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Heartworm Lifecycle
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Exotics
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Is Heartworm on the Rise?
In the latest AHS heartworm incidence survey, veterinarians weighed in on incidence trends. This infographic breaks it down.in
Category: InfographicsCanine | Feline | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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The Southeast has the Highest Incidence
The Southeast has the dubious distinction of having the most cases of heartworm in the country. This infographic has details.
Category: InfographicsCanine | Feline | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Mosquito Mayhem
What's the link between mosquitoes and heartworm disease? This infographic shares 5 facts.
Category: InfographicsCanine | Feline | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Who Gets Heartworms?
You probably know dogs and cats get heartworm disease, but did you know lots of other species do, too? This infographic takes you on a walk on the wild side.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Exotics | Other | Veterinary Professionals | Pet Owners
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10 Ways to Stay on Top of Heartworm Prevention
You don't want to forget your pet's heartworm preventive! Here's 10 tips to help you remember.
Category: InfographicsCanine | Feline | Prevention | Exotics | Other | Veterinary Professionals | Pet Owners
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What Raises The Risk Of Heartworms?
From weather to wildlife, there's multiple contributors to heartworm risk. Check out some common causes in this infographic.
Category: InfographicsCanine | Feline | Prevention | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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24 Hour Risk Graphic: Cat
Is there a time of day when heartworms aren't a risk for your cat? No!
Category: InfographicsFeline | Prevention | Veterinary Professionals | Pet Owners | Incidence
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24 Hour Risk Graphic: Dog
Is there a time of day when heartworms aren't a risk for your dog? No!
Category: InfographicsCanine | Prevention | Veterinary Professionals | Pet Owners | Incidence
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Heartworm Tall Tales - Cats
It's a myth that cat's don't get heartworms.
Category: InfographicsFeline | Treatment | Veterinary Professionals | Pet Owners
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Heartworm Tall Tales - Indoor
Indoor cats can get heartworms if they're not on prevention.
Category: InfographicsFeline | Prevention | Diagnosis | Veterinary Professionals | Pet Owners
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Heartworm Tall Tales - Testing
Dogs on heartworm prevention still need annual heartworm testing.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Veterinary Professionals | Pet Owners
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Heartworm Tall Tales - Transmission
Heartworm is spread by mosquitoes, not spread directly between pets.
Category: InfographicsCanine | Treatment | Veterinary Professionals | Pet Owners | Incidence
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Heartworm Tall Tales - Composite
Make sure you can separate myth from fact when it comes to heartworm knowledge. Your pet's life could depend on it!
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Life Cycle | Veterinary Professionals | Pet Owners | Cost | Incidence
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Heartworm Disease In Dogs
The early signs of heartworm disease in dogs are subtle, which advanced disease causes serious disease--and even death, according to this infographic.
Category: InfographicsCanine | Prevention | Treatment | Veterinary Professionals | Pet Owners
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Heartworm Disease In Cats
The signs of heartworm disease in cats from range from coughing and nausea soon after infection to serious disease and even death when it is advanced, according to this infographic.
Category: InfographicsFeline | Prevention | Treatment | Veterinary Professionals | Pet Owners
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Heartworm By The Numbers
Add it up and heartworm "numbers" in this infographic will tell you how serious a problem heartworm disease is for pets.inci
Category: InfographicsCanine | Feline | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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Take 5 on Feline Heartworm Disease
Do you need a reason to give your cat heartworm prevention? This infographic gives you FIVE.
Category: InfographicsFeline | Prevention | Diagnosis | Veterinary Professionals | Pet Owners
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Can we turn down the dial on heartworm risk?
From strategies that lower the risk of heartworm to behaviors that increase it, this infographic will help you understand the concept of heartworm risk.
Category: InfographicsCanine | Feline | Prevention | Life Cycle | Exotics | Other | Veterinary Professionals | Pet Owners | Incidence
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The ABCs of Heartworm Disease
There are 26 letters in the alphabet. And this infographic shares 26 facts you need to know about heartworm in pets.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Life Cycle | Exotics | Other | Veterinary Professionals | Pet Owners | Cost | Incidence
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Significance of Heartworm Disease
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Exotics
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Heartworm Incidence: Up or Down?
Category: InfographicsCanine | Prevention | For Owners | Shelters
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Protect Your Pet Handout
Numbers, numbers, numbers in this infographic--and it adds up to heartworm disease being a serious, nationwide threat.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Veterinary Professionals | Pet Owners
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Heartworm Incidence Map
Category: InfographicsCanine | Prevention | Diagnosis | Treatment | For Owners | Shelters
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Significance of Heartworm Disease (2013)
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | For Owners | Shelters
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Heartworm Vectors
Everyday actions can expose pets to heartworm. This infographic gives examples of how transmission can happen.
Category: InfographicsCanine | Feline | Prevention | Life Cycle | Veterinary Professionals | Pet Owners
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Weigh the Costs
Which can cost more--heartworm prevention or treatment? This infographic helps you weigh the costs.
Category: InfographicsCanine | Prevention | Treatment | Veterinary Professionals | Pet Owners
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1 Reason: Heartworm in Cats
Heartworm prevention is a must for cats. This infographic explains why they're worth it!
Category: InfographicsFeline | Prevention | Veterinary Professionals | Pet Owners
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A Tale of 2 Kitties
Cats that are protected against heartworms can live longer, healthier lives. This infographic explains why.
Category: InfographicsFeline | Prevention | Veterinary Professionals | Pet Owners
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The Mighty Mosquito
Mosquitoes may be small but they present a mighty threat to unprotected pets. This infographic explains the link between mosquitoes and heartworm disease.
Category: InfographicsCanine | Feline | Prevention | Life Cycle | Exotics | Other | Veterinary Professionals | Pet Owners
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A Dog's Heart is a Place for Love, not Heartworms
This infographic explains why heartworm prevention = LOVE.
Category: InfographicsCanine | Prevention | Pet Owners
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Testing Algorithm
Just 10 minutes is all it takes each year to test your dog for heartworms. This infographic helps you determine if your dog should be tested.
Category: InfographicsCanine | Diagnosis | Veterinary Professionals | Pet Owners
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Does My Dog Need a Heartworm Test?
Category: InfographicsCanine | Diagnosis | Veterinary Professionals | Pet Owners
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Dogs VS Cats
Dogs are definitely different from cats but they both need heartworm prevention, according to this infographic.
Category: InfographicsCanine | Feline | Prevention | Diagnosis | Treatment | Veterinary Professionals | Pet Owners
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