Your Dog Has Heartworm Disease: Now What?

Pet owners fear their pet receiving a positive heartworm test. It’s a valid fear!

These worms, which can grow up to a foot long and live for five to seven years, can permanently damage an animal’s heart and blood vessels and may cause death if left untreated.

The best option is prevention, which is simple. Treatment is complex; however, if treatment is necessary, early intervention is crucial to minimize the damage the heartworms can cause.

Heartworm Disease Prevention

Heartworm disease is almost 100 percent preventable, but you must follow an appropriate prevention regimen. Unfortunately, medication is forgotten, or dogs may vomit or spit out their dose of preventive. We chose our heartworm prevention options with these thoughts in mind, making it simple to protect your pet against heartworm disease. Here are our two favorite heartworm prevention products:

• Heartworm chewables — We have a tasty, chewable tablet that most dogs think is a wonderful snack. Heartworm prevention is administered as a monthly treat.
• Six-month heartworm injection — Many pet owners love the option of the heartworm injection. This is like giving a vaccine and is effective for six months. This means no more missing doses! Both options are labeled as a preventive for some intestinal worms, but neither protects against fleas, ticks, or lice (for this, we recommend a product called Simparica).

We mostly follow the American Heartworm Society’s guidelines concerning heartworm prevention: Think 12. Make sure you protect your pet from heartworms 12 months a year with no winter break, and test every 12 months to ensure a negative heartworm status. Mosquitoes may be less active in winter, but they can still sneak into your home and infect your pet.

We are not as strict as the American Heartworm Society, and we recommend a heartworm test at least every two years to verify a negative status, although yearly is even better. We reward pet owners who purchase a year’s supply of oral heartworm preventive or who choose the injectable form by discounting the cost of the heartworm test to $5. There is no reason to skimp on prevention of this deadly disease.

Treatments for Heartworm Disease

We will plan your pet’s treatment protocol according to the disease stage. Some animals may first require antibiotic and steroid therapy, as well as pain medication. If we inject melarsomine, an arsenic-based compound, deep into your pet’s lumbar muscles to kill the adult heartworms, medication may be warranted to alleviate your pet’s pain and discomfort.

If your dog is classified at stage one or two, treatment will consist of two melarsomine injections 24 hours apart. For a pet in stages three or four, the melarsomine injections will be split into three treatments that involve an initial injection, followed a month later by two back-to-back injections.

After the injections, your pet will need standard heartworm preventives to eliminate the worms at their larval stage, called microfilariae, before they reach adulthood. It’s important to:

• Keep your pet calm by restricting all activity that may increase heart rate or blood pressure. If your pet is too active, the worms can collect in the pulmonary blood vessels as they die and cause potentially fatal blood clots. Keep her indoors, use a leash for bathroom breaks outside, and limit excitement.
• Begin using a heartworm preventive one month after your pet’s final treatment. Heartworm prevention kills off the microfilariae your pet has accumulated over the previous month so they do not mature to adult heartworms.
• Return for a follow-up heartworm test six months after your dog’s final treatment to ensure she is disease-free. If not, further treatment may be needed.

Heartworm prevention, which is simple and relatively inexpensive, can keep your pet from needing the complicated, expensive treatment. If your pet isn’t on a regular heartworm preventive, or if you missed a dose, call us to schedule a heartworm test. If you are interested in a simpler heartworm-preventive option, schedule an appointment for an injection to prevent this deadly disease.