Heartworm Treatment

Heartworm disease can be life-threatening if left untreated and/or lead to severe complications to the animal's health. Our veterinarian conducts thorough diagnostics and creates a tailored treatment plan to ensure an effective treatment and safe recovery. Don’t wait—early intervention is key to having an effective treatment plan and prognosis!

OPTION #1

3 Injection Protocol

Recommended by The American Heartworm Society.

About 98% effective (2 % of dogs will test positive at post-treatment test 4 months after the last injection).

The following standard of care for heartworm treatment in dogs to maximize the safety and efficacy of treatment:

Begin exercise restriction as soon as diagnosed heartworm positive.
Staging with bloodwork (CBC) & chest x-ray and providing nursing care if symptomatic or reaction.
Pre-treat with heartworm preventative once monthly for two months, and Doxycycline for one month beginning 60 days, before any Immiticide treatments. This reduces the risk of pathology associated with the death of heartworms and “Wolbachia syndrome.”
A 3-injection protocol using Immiticide (1 injection, wait one month, and then final two injections given 24 hrs apart)
Stricter exercise restrictions after the first injection and 6-8 weeks after the final two injections.
Oral prednisone on a tapering dose after each injection to reduce inflammation. Additional post-injection pain medication as needed.

OPTION#2

2 Injection Protocol

No longer recommended

About 90% effective (10% of dogs will still be heartworm positive at their 4-month post-treatment test and require a second 2-shot protocol treatment).

Faster kill of the adult heartworm, causing a potentially higher risk for post-treatment thromboembolic event.

OPTION #3

Slow Kill Method

This method is NOT recommended

The myth that the “slow kill” method is “just as good” as Immiticide therapy may have originated from a 2001 study. This study demonstrated that 30 months (2.5 yrs) of ivermectin (Heartgard Plus) in monthly preventive doses reduced 7-month-old worms by 84% and 8-month-old worms by 56%. However, the older the worms are at the start of “slow kill” therapy, the less efficacious the therapy is in the patient.

“Slow kill” treatment is less effective than the Immiticide treatment recommended and may not eliminate all the worms—even after 30 months or more of treatment. During the lengthy “treatment” period, the worms in the dog’s body will continue to damage the heart, lungs, and pulmonary vasculature. Strict exercise restriction is needed for the entire time the animal harbors worms. The risk for selection of resistant heartworm populations is increased.

What to Expect During the Treatment Process

Medications Prescribed:

Before Injections:

- Heartworm prevention (Ivermectin or Moxidectin based) – Heartgard Plus, Iverhart Plus is given monthly and for the rest of the pet’s life. *This is not included in the cost of treatment outlined below. Expect to pay ~$10 per monthly dose.*
- Doxycycline – Antibiotic; Taken twice daily with food for at least 30 days before starting injections. Can cause stomach upset, especially on an empty stomach. Used to eliminate Wolbachia syndrome (reaction of the dog’s body to exposure to Wolbachia, a parasite within the heartworm).

At the time Injections are administered:

- Prednisone – Anti-inflammatory; Always to be given with food. Depending on the patient, may be given before injections when starting monthly heartworm prevention. Always given after injections for up to 3 weeks.
- Gabapentin – Pain reliever; May cause mild sedation or stomach upset. This medication helps with the pain caused by the intramuscular injections of the heartworm treatment (which can cause soreness, lameness, and pain, sometimes severe).
- Trazodone (optional) - anti-anxiety sedative. Available for high-energy pets to restrict activity immediately following the injection period. This is not included in the cost of treatment outlined below. Expect to pay ~$10 per monthly dose.

Outline of Treatment Process

*Outlined for 3-injection treatment option*

Day 0 - the day the pet is diagnosed with Heartworm disease

- START ACTIVITY RESTRICTION and continue for the remainder of the treatment process.
- Determine if proceeding with the two versus three injection protocol
- Send out for a comprehensive bloodwork panel with a confirmatory test
- Start Doxycycline medication for 30 days
- Start Heartworm prevention and continue once monthly for the remainder of the pet's life.

Day 30 - Administer monthly heartworm prevention.

Day 30-60 - 1-month waiting period before starting injections.

Day ~60 - Injection #1

- Administer monthly heartworm prevention
- Pet will be hospitalized for the day (drop-off early morning, pick up late afternoon)
  - Your Pet will receive the injection along the spine. A patch of fur will be shaved and prepped for the deep intra-muscular injection.
  - Your pet will be sent home with pain and anti-inflammatory medication.

Day 90 - Injection #2

- Administer monthly heartworm prevention
- Pet will be hospitalized for the day (drop-off early morning, pick up late afternoon)
  - Your Pet will receive the injection along the spine. A patch of fur will be shaved and prepped for the deep intra-muscular injection.
  - Your pet will be sent home with pain and anti-inflammatory medication.

Day 91 - Injection #3

- Pet will be hospitalized for the day (drop-off early morning, pick up late afternoon)
  - Your Pet will receive the injection along the spine. A patch of fur will be shaved and prepped for the deep intra-muscular injection.
  - Your pet will continue the medications sent home on Day 90.

Day 120-135 (30-45 days after the last injection)

- Microfilaria test at the clinic ($25)
- This should NOT coincide with monthly heartworm prevention administration.

Day 270-365 - (6-9 months after the last injection)

- Perform a Heartworm test at the clinic ($20-$35)