Vet Blog

Heartworm Disease in Dogs: Symptoms, Treatment, and Prevention

May 10, 2021

Heartworm in dogs is a serious disease that can be fatal if left untreated.

The sooner your dog gets a diagnosis, the better their chances of making a full recovery. If you suspect your dog has contracted heartworm, the expert team at Animal Care Center of Castle Pines can help. We'll provide the urgent care and treatment that your pet needs to be happy and healthy again.

Heartworm Disease

Heartworm disease is caused by worms (Dirofilaria immitis) which live in the heart, lungs, and blood vessels of animals. These worms can grow up to 12 inches in length. Heartworm can lead to heart disease, severe lung disease, heart failure, and permanent organ damage.

Dogs are natural hosts for heartworms-these parasites can live, grow into adults, and reproduce within a dog's body. Because mosquitos play an important role in the transmission of heartworms, dogs in regions where mosquitoes are more prevalent have a higher likelihood of contracting heartworm disease.

Heartworm Transmission

The transmission of heartworms from one dog to another dog, or from an infected mammal to a dog is fairly simple. Mosquitos are typically the transport vessel for heartworms.

First, a mosquito will bite an animal already infected with heartworms, picking up baby heartworms from the animal's bloodstream. The mosquito, now carrying baby heartworms, will bite a healthy dog, and the heartworm larvae will travel through the bloodstream to the dog's heart, lungs, and blood vessels where they can then mature and reproduce.

Adult heartworms can live inside a dog for up to 7 years, consistently reproducing and causing significant damage.

Symptoms of Heartworm in Dogs

For the first few months of the disease, in its early stages, your dog probably won't show any symptoms at all. However, the longer the infection goes untreated, the more likely symptoms are to develop.

Signs of heartworm disease include:

  • Coughing
  • Fatigue after activity
  • Refusal to participate in any activity
  • Decreased appetite
  • Weight loss

If your dog has a large number of heartworms, they are at risk of developing sudden blockages of blood flow within the heart. This blockage is called caval syndrome.

Caval syndrome symptoms include:

  • Sudden onset of labored breathing
  • Pale gums
  • Dark or bloody urine

If your dog's infection gets to this stage, they will not survive without immediate emergency surgical removal of the heartworm blockage.

Treatment for Heartworm Disease

If your dog tests positive for heartworm disease, it is important to begin treatment immediately. Your dog will get an antigen test, and then a microfilaria test in order to confirm the findings or the antigen steps. There are a few steps when it comes to treating heartworms. Each step is incredibly important in getting your dog back to their happy, healthy self.

Restrict Exercise

In pets with heartworms, physical exertion will increase the rate of damage. Limit all normal activities until your dog is fully cleared of any heartworms in their cardiovascular system.

Administer Treatment

Treatment lasts for approximately 91 days, and includes injections, limiting activity, and administering adjunct steroids. Recovery can last up to a full year, with regular check-ups to ensure the heartworms have been eliminated completely. Dogs with few to no symptoms usually recover fully. However, dogs with more severe infections have a higher chance of complications.

Test and Prevent

Six months following the course of treatment, we will give your dog a heartworm test to ensure that all of the heartworms have been eliminated. You should also administer heartworm prevention medication year-round for the rest of your dog's life to prevent them from contracting heartworms again.

Heartworm Disease Prevention

The best way to treat heartworm disease is by stopping it before it starts. You should keep your dog on a safe, FDA-approved heartworm medication year-round. Medications for heartworm include ivermectin, milbemycin oxime, and moxidectin or selamectin. These medications have proven extremely effective when it comes to killing heartworms. Your veterinarian at Animal Care Center will prescribe the right medications for your pet.

Heartworm medication comes in three different forms: a chewy pet-friendly pill, a topical cream applied between the shoulder blades, or an injection every 6 months. Always follow your veterinarian's instructions-they will tell you the correct dose and how often to administer the heartworm medication.

Heartworm Treatment at Animal Care Center of Castle Pines

If you're in the Castle Pines area and suspect that your dog may have heartworms, contact us today to set up an appointment for testing. We have all of the necessary equipment on-site to quickly and accurately test your dog for heartworm disease. If your dog is showing symptoms of heartworm disease, don't hesitate-call us today.