Heartworm disease is something that many pet owners have heard about but not something we think about all that often. Who wants to think about their pet suffering from parasitic worms living in their heart and blood vessels?

Heartworm disease is a fatal disease that is common in the United States. Fortunately, it is an easily preventable disease with routine diagnostic testing and monthly preventative treatments.

What would you like to know about heartworm disease, diagnostics, prevention, and treatments? Let’s take a look at the most frequently asked questions regarding heartworm disease.

What is heartworm disease?

Heartworm disease is a serious and potentially fatal disease common in pets across the United States and other parts of the world. The disease is caused by foot-long tubular parasites—also known as heartworms—that live, mate, and reproduce inside a pet’s heart, lungs, and blood vessels causing complications such as heart failure, lung disease, and possible irreversible damage to other organs.

Heartworm disease is common in dogs but can affect other mammalian species—some common in urban areas like Elgin—making them prominent carriers of the disease and facilitating its spread. Coyotes, wolves, foxes, and even sea lions are among those that can be affected by heartworm disease.



How is heartworm disease spread?
Mosquitoes play a central role in the lifecycle of heartworms. Adult female heartworms
reproduce inside their hosts—dogs, foxes, coyotes, wolves, etc.—and produce microscopic
worms called microfilaria that circulate in the bloodstream. When a mosquito bites an infected
animal, the mosquito ingests the microfilaria and deposits the worms into the next susceptible
animal it bites. Once in a new host, it takes roughly 6 months for larvae to mature into adult
heartworms which can live 2-7 years depending on the host they are inhabiting.
What are the signs of heartworm disease?
Symptoms of heartworm disease can be very pronounced, subtle, or nonexistent.
Early Signs:

  • Coughing
  • Reluctance to exercise
  • Fatigue/Lethargy
  • Decreased appetite
  • Weight loss
    Progressive Signs:
  • Heart failure
  • Swollen belly
  • Caval Syndrome
    o Labored breathing
    o Pale gums
    o Dark bloody or coffee-colored urine

Progressive Signs:

  • Heart failure
  • Swollen belly
  • Caval Syndrome
    • Labored breathing
    • Pale gums
    • Dark bloody or coffee-colored urine

How significant is my pet’s risk for heartworm disease?
Heartworm disease is becoming more prevalent each year. It has been diagnosed in all 50
states and spreads to new regions of the country each year. From 2013-2016, there has been a
21.7% increase in cases of heartworm! Whether you believe your local area has a heartworm
problem or not, risk factors such as climate variation and the presence of wildlife carriers, or
even if you travel with your pet, put your pet at risk for contracting heartworm disease.
Just check out these incidence maps:

“My pet is an INDOOR pet…”

Indoor pets ARE at risk for heartworm disease! Even if your pet doesn’t go outside or only goes outside for a very brief amount of time whether to walk or go to the bathroom, mosquitos can infect them in that timeframe and infected mosquitos CAN get in the house.

What do I need to know about heartworm testing?

Because heartworm is a progressive and fatal disease, annual testing is necessary. The earlier heartworm disease is detected, the sooner we can treat the pet and better the chances are that the pet will recover. A heartworm test requires a small amount of blood and the test can be performed quickly by a veterinary technician or a veterinarian. Even if you give your pet year-round heartworm prevention, a heartworm test is still needed to make sure the prevention is working for your pet—especially if you have forgotten doses or give it intermittently. If the latter is the case for you, more frequent heartworm testing might be required.

What if my pet tests positive for heartworm disease?

If your dog becomes infected, don’t panic! Most infected dogs experience successful treatments if started right away.

Treatment is as follows:

  1. Confirm the diagnosis with additional testing. Treating heartworm disease is very expensive and intense and we want to be absolutely sure before beginning treatment.
  2. Restrict exercise. This might be very difficult but physical activity puts extra stress on the heart and lungs by increasing the rate that heartworms cause damage to those organs which may increase your pet’s chances of developing complications.
  3. Stabilize your pet’s disease. Before any treatment can begin, the disease must be stabilized with the appropriate therapies which can take several months in severe cases.
  4. Begin treatment. Heartworm treatment begins after therapies, such as antibiotics and steroids, and is given through a course of three injections. Cage restriction and strict exercise restriction during injections is necessary to ensure your pet has successful treatment and restriction should continue 6-8 weeks after the third injection.
  5. Recheck. Thirty days after the last injection we will need to recheck your pet for heartworm microfilariae.
  6. PREVENT and retest. With the help of your veterinarian, you will need to establish a year-round heartworm prevention regimen. Six months after, we will need to recheck your pet with a heartworm test.

How much is heartworm prevention?

You can protect your pet from heartworm disease for as little as $12.16 a month OR ~$145.92 a year depending on your pet’s weight range. It may seem pricey but year-round heartworm prevention is much more cost effective than treating the disease. 

You can purchase heartworm prevention at our clinic or through our online pharmacy on Vetsource.

(Not so) Fun Facts:

  • In the U.S., heartworm disease effects more dogs than any other canine insect born parasitic disease
  • Only 2 out of 10 dogs are on 12-month prevention
  • Another 2 out of 10 are on inconsistent prevention
  • The last 6 out of 10 are not on any prevention
  • 30% of pet owners think that flea and tick preventatives treat heartworm disease which is not the case! Make sure you are using heartworm preventatives such as Heartgard or Sentinel in conjunction with you flea and tick preventatives such as Nexgard or Frontline!

With more and more pets not being on consistent, year-round heartworm prevention—or on the wrong prevention—your pet is even more at risk! Don’t keep your pet at risk, call us today and we will help you protect your pet from heartworm disease for life.

Call us at (847) 695-7387

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