Local Heartworm Testing: Keep Your Pets Safe

A dog being fed heartworm prevention medicine.
Author: Natalie Kienzle
Posted: November 20, 2023
Modified: November 20, 2023

Local heartworm testing is right around the corner through the VOCAL Community Clinic’s drive-thru events. It’s simple, available, and vital. For some pet owners, the cost of testing and prevention can stretch budgets thin. As an active animal welfare advocate right here in Ocala, VOCAL understand this. That’s our commitment: to enlighten pet owners about the significance of testing and to provide practical solutions for it.

The American Veterinary Medical Association (AVMA) emphasizes that testing for heartworms is essential for detecting heartworm disease, a severe and potentially deadly infection caused by parasites. Heartworm infestations are preventable through a variety of monthly medications and even a vaccine. 

We’ll review some basic truths about heartworm disease and go through just how important it is to both test and prevent. 

The Basics of Heartworm Testing

If you’re a dog owner, it’s important to know about heartworm disease and how to test for it. Heartworm disease is a potentially deadly infestation that can be detected with a simple blood test

Here are the basics of heartworm testing and why it’s considered a necessary part of pet health and welfare.

How To Test For Heartworm

There are two types of heartworm tests: antigen tests and microfilaria tests.

  • Antigen tests can pick on the presence of adult female heartworms
  • Microfilaria tests detect the presence of heartworm larvae in the bloodstream

To perform an antigen test, a small blood sample is taken from your dog and tested for the presence of heartworm antigens. These are markers left in the blood stream because of foreign substances, like heartworm larvae.

This test is done through a veterinarian and usually provides results within minutes.

A microfilaria test requires a blood sample as well, but it is sent to a laboratory for testing. This test can take longer to get results, but it is more accurate than an antigen test. In some cases, it can detect heartworm much earlier since it’s based off the larvae. 

An antigen test may give a false negative in cases where the larvae have not matured or spread enough to cause the body to develop antigens. 

Local heartworm testing, image of a heartworm test.

Heartworm Disease in Florida

Florida is a high-risk state for heartworm disease due to its warm and humid climate, which is perfect for the mosquitoes that transmit the disease. The American Heartworm Society (AHS) indicates that Florida is an endemic area for heartworm disease, due to its year-round presence.

Our state is home to 11 out of the 16 different types of mosquitos capable of carrying heartworm larvae, and they dwell in fresh and saltwater habitats. In other words – all of Florida. 

The AHS’ heartworm incidence map of 2022, shows that in most of Florida, individual clinics report between six and 25 cases of heartworm positive pets in a single year. There are also growing pockets of regions where clinics report over 100 positive tests per year. 

That’s thousands of dogs each year becoming infected with a disease that is easily preventable. 

Heartworm Infections in Dogs by County

The number of positive heartworm cases in dogs varies by county in Florida. According to a survey conducted by the University of Florida, the highest prevalence of heartworm was found in the northern and central regions of the state. 

Most Affected Counties in North and Central Florida*

Dixie100+ Cases
Gilchrist100+ Cases
Levy100+ Cases
Marion100+ Cases
Alachua100+ Cases
Escambia100+ Cases
Jackson51–99 Cases
Leon51–99 Cases
Jefferson51–99 Cases
Putnam51–99 Cases
*according to average number of cases reported by local authorities. Source: American Heartworm Society

Marion County falls in among the top six for the presence of heartworm disease in the North and Central Regions. Further south, there are even more counties in the highest ranges. 

For these reasons and more, regular testing is crucial. If your dog does test positive for heartworm, a veterinarian can recommend a treatment plan to help manage or even cure the disease.

However, the treatment of heartworm is quite expensive. This is why VOCAL seeks to do as much as possible to help owners get testing and prevention for all their pets. 

Importance of Regular Heartworm Testing

Regular heartworm testing is a crucial step for maintaining your pet’s health. Remember, heartworm disease is ultimately fatal. Fortunately, it’s preventable and treatable if detected early. 

How Often do Dogs Need to be Tested for Heartworm?

Dogs (and cats) should be tested for heartworms once a year, even when taking heartworm prevention medication. 

In medicine, nothing is guaranteed. Any manufacturer or vet can tell you that heartworm medication is NOT 100% effective, so there does remain a slight possibility of infection. Annual testing helps with early detection and immediate treatment of any heartworm infections.

Do Cats Need to be Tested For Heartworm?

Yes, cats should be tested for heartworm disease. If they spend time outdoors or live in an area where heartworm disease is prevalent, they are at risk. 

Heartworm disease in cats isn’t as common, but when it happens, it’s far more dangerous. There are no recommended treatments for heartworm disease in cats that leave them cured. Therefore, prevention is key.

How Pets Benefit From Regular Testing

Regular heartworm testing can benefit your pet in many ways, including:

  • Early detection and treatment of heartworm disease
  • Prevention of serious health complications
  • Peace of mind for pet owners
  • Cost savings by avoiding expensive heartworm treatment

It’s important to note that low-cost heartworm tests are available through VOCAL Drive-Thru vaccine clinics. We’re working hard to keep the process simple and make it possible for pet owners to keep up with consistent heartworm testing.

VOCAL’s monthly drive-thru events offer heartworm tests for just $18. When your pet is seen for testing, they will also get a physical exam from our qualified veterinarians. 

Dog receiving an intramuscular injection as part of heartworm treatment.

Heartworm Testing and Prevention vs Treatment

Yes, a heartworm positive dog can be treated with the right medications, provided that it’s detected with enough time. The real goal is to keep dogs from getting it at all. Fortunately, heartworm infestations are preventable with monthly medication. 

The goal of testing, aside from making sure that your pet isn’t positive, is to get them started on some kind of prevention to hopefully keep treatment from ever being needed. 

How Effective is Heartworm Prevention?

Heartworm prevention is extremely effective when used correctly. In fact, heartworm preventives are over 99% effective at preventing heartworm disease when given on a regular basis. Most heartworm preventives are given monthly, although there is a vaccine that can provide protection for 6 to 12 months. 

Heartworm prevention is much less expensive than heartworm treatment. At a private clinic, heartworm treatment can cost owners between $1,000 to $3,000. The treatment is rough, and success is never guaranteed. 

A pet that has been treated for heartworm disease will not develop immunity either. Without prevention, they will be just as prone to reinfection as any other dog.  

By contrast, a six-month supply of heartworm prevention averages between $30 to $70 depending on the size of your pet. 

Average Cost of Heartworm Prevention by Weight Range

Pet Weight RangeCost of 6 Month Supply*
Up to 25 lbs$36
26 – 50 lbs$45
51 – 100$55
Over 100$91 
*based on a prevention where the primary ingredients are ivermectin & pyrantel

Even at the upper range of the price scale, that’s about two years worth of prevention for the minimum price you could hope to pay for treatment of an infected dog.

There are other options that may cost more because they prevent other issues, such as intestinal parasites, fleas, or ticks. Regardless of what you end up choosing, by preventing heartworm disease, you can help your pet stay healthy in any environment.

Can I Give my Dog Heartworm Medicine Without Testing?

It can be tempting for some to try to cut corners, getting the medication and not the testing. While heartworm medication is important for preventing heartworm disease, it is important to note that testing is necessary before administering any medication.

Here’s why:

  • For dogs that have tested positive for heartworm, giving them preventative medicine can lead to serious complications, including death. Much depends on the stage of infestation.
  • Follow-up testing and exams can also identify other health issues that could impact a dog’s ability to take heartworm medication, such as tick-borne diseases.

Some antigen tests used by veterinarians to detect heartworm can also pick up on other common blood-borne illnesses. 

  • Lyme disease
  • Ehrlichia
  • Anaplasmosis 

This is why heartworm testing is only conducted in veterinary clinics and offices under the supervision of a licensed doctor of veterinary medicine (DVM). Even if someone did manage to obtain a test to conduct at home, they would not be able to submit it as proof to a heartworm prevention supplier. 

Suppliers will only sell prevention with confirmation of a negative test from a licensed DVM. 

What is the Best Affordable Heartworm Preventative?

There are a variety of heartworm preventatives available on the market, and the best one for your dog will depend on a number of factors. 

Among the things a doctor will consider are:

  • Age
  • Weight
  • Overall health
  • Medical history 

Here are some of the most popular and affordable options:

  • Ivermectin-based preventatives, such as Heartgard and Tri-Heart Plus, are effective and affordable options for preventing heartworm disease.
  • Milbemycin-based preventatives, such as Interceptor and Sentinel, are also effective and may offer additional protection against other parasites.
  • Topical preventatives, such as Revolution and Advantage Multi, are applied directly to the skin and can offer protection against heartworms as well as other parasites.
  • A moxidectin-preventitive, of which the only approved versions are ProHeart 6 and 12, is an injectable form of prevention given every six or twelve months. 

VOCAL provides a number of options for the community we serve. However, should you wish to get a form of prevention we do not offer, our negative heartworm test results are acceptable forms of proof. You may take them to a private vet if you have one, or even order from an online supplier. 

Woman holding a beagles payw.

Consulting with a Veterinarian at VOCAL Community Clinic

If you are concerned about the cost of heartworm testing and medication, consider consulting with a veterinarian at VOCAL Community Clinic. VOCAL offers affordable veterinary care and can help you find the best course of action for your dog’s health. 

  • Low cost spay/neuter surgeries
  • Dental cleanings
  • Rabies vaccines and core vaccines
  • TNR Programs for cats

We can also provide assistance on a case-by-case basis for families struggling financially to be able to get needed services for their pets. 

Complete a Program Services Form and VOCAL will find solutions that work for you. Together, we can improve the lives of pets throughout our community and beyond. 

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