Dog heartworm disease can be a dreaded diagnosis with frightening symptoms, but thankfully it is easily avoided with regular preventative medication. If your dog hasn’t been taking a preventative and you suspect heartworm symptoms, we’re glad you found our website.

We’ve answered some of the most frequently asked questions about dog heartworm disease here. However, if you’re in the Las Vegas, NV area, we’d love to help you treat and prevent heartworm. The first step is to get your dog seen for a test if they haven’t had one recently, so please call us at (702) 213-4513. 

What is heartworm disease, and how can it affect my dog?

Heartworm is a parasite, or “worm,” that lives in the heart, and is detected with a blood test.

Signs that your dog may have heartworm disease include:

  • Trouble breathing
  • Persistent cough, which can be moist or dry
  • Weight loss 
  • Blood coming from the nose and mouth

Unfortunately, there are rarely signs during the early stages of heartworm, making annual screening and prevention vital. By the time we see signs, it's likely very advanced. Long-term heartworm disease has a serious impact on a dog’s health, compromising their heart, lungs, and blood circulation.

How does my dog catch heartworms?

Heartworm is transmitted when a mosquito bites an infected host, then passes the parasite to your dog through a bite. The heartworm larva develops into a worm and then transmits 5 to 10 tiny worms into your dog’s skin. Those worms travel through your dog's body into the bloodstream and eventually become adult worms that are approximately 12 inches long, before migrating to the pulmonary arteries located on the right side of the heart. It’s important to note that indoor dogs are not immune to heartworm disease, as mosquitoes can fly into your home at any time and bite them. 

Can dog heartworms be prevented?

Dog heartworms are a preventable disease with oral tablets or injectable medications that prevent the larvae from developing into adult heartworms. While no prevention is 100% effective, it is your dog’s best chance—whether oral, topical, or injected by your veterinarian.

What are the signs that my dog may have heartworm?

Many dogs are asymptomatic in the early stages of the disease. As it progresses, you might notice a slight cough, then as more moderate to severe signs develop and they’re brought in for an exam, we can hear a heart murmur. They may experience an enlarged liver or enlarged heart. They may get fluid that backs up into their lungs and the abdomen. The signs you are likely to notice at home include difficulty breathing, exercise intolerance, lethargy, and sometimes bulging ribs because they can't catch their breath. 

What are some middle to late-stage symptoms of heartworms?

Middle to late-stage symptoms include: 

  • Abnormal heart and lung sounds
  • Enlarged liver
  • Panting at rest

What can be done to stabilize my dog's heartworm disease?

First and foremost, bring your dog into Boca Park Animal Hospital, where we’ll provide oxygen support if needed, and give fluids to help stabilize the symptoms. We’ll collect blood to test for adult female worms, which are the majority of the worms that affect dogs. Once we have a positive test, we inspect the blood for baby worms circulating in the body. We have a positive heartworm dog if we have those two things, and we will begin talking about treatment. 

There are three phases to dog heartworm treatment:

  1. We start the dog on medication to prevent further infestation, which is also a heartworm preventative. 
  2. Then we start an antibiotic called Doxycycline to deprive the heartworm of the bacteria it needs to survive. These worms need to be eliminated in stages, as there are often many of them, they are about 12 inches long, and they are located on the right side of the heart and pulmonary arteries. If the worms are eliminated too quickly, your dog may experience complications. 
  3. Eventually, we will administer three injections of a medication called Immiticide or Melarsomine. Once this has all been initiated, we will discuss a regular regimen of heartworm disease prevention. 

At what age should I start my dog on heartworm prevention?

We like to start prevention as early as eight weeks old, but the first testing can be done at six months old. Your first puppy vaccine appointment is an excellent time to start prevention. Heartworm prevention for dogs that aren't infected is designed to prevent the disease, as even puppies are exposed to mosquitoes. When mosquitoes bite a dog and deposit baby worms into their skin, the worms are susceptible to being destroyed by these heartworm preventatives before they enter the bloodstream. This is why it’s important that we start preventatives early, before the worms can do any damage.

How will a veterinarian determine if my dog does have heartworm?

We’ll use a very simple blood test to diagnose heartworm, which only takes about three drops of blood and the results are ready in 15-20 minutes. If it's positive, we may follow up with additional testing, such as X-rays, ultrasound of the heart, and additional blood tests.

Why is early detection and diagnosis of heartworm so important?

Early detection is vital because heartworm can be fatal if left to progress, and the worm burden – the number of worms that have accumulated - can be lessened. While your dog is asymptomatic, worms start replicating and reproducing inside the system. Early detection and diagnosis are essential in the prognosis because we can avoid the more serious symptoms and severe complications that can lead to death. All dogs should be tested every year, but you should have your dog examined immediately if you suspect heartworm disease. If your dog has not had a recent heartworm test or is not on a preventative, one of the first things we're going to recommend at Boca Park Animal Hospital is a heartworm test to rule it out.

How long does treatment take?

Treatment can take months since it requires multiple injections a certain number of months apart. It definitely requires time and attention at home, as you will need to be strict with cage rest and avoid any strenuous activity.

If you have further questions about heartworm disease, reach out to your veterinarian. If you live in or near Las Vegas, NV, we’d love to discuss a preventative for your dog, so please don’t hesitate to call us at (702) 213-4513.