Heartworm Treatment Cost in Washington (2026)

How much does heartworm treatment cost for a dog in Washington?

Heartworm treatment in Washington averages $1,720 in 2026 — 15% above the national average. The standard melarsomine protocol (3 injections over 2 months plus pre-treatment bloodwork, X-rays, and strict exercise restriction) typically runs $1,000–$2,500 total. Annual heartworm prevention costs $140 and is far less expensive.

Is there a cheaper heartworm treatment option in Washington?

The 'slow kill' method (monthly ivermectin without melarsomine) is cheaper but takes 1–2 years, doesn't kill adult worms directly, and is no longer recommended by the American Heartworm Society due to resistance concerns. The standard melarsomine protocol at $1,720 in Washington is the only AHS-approved treatment. Humane societies and veterinary schools sometimes offer discounted treatment.

What happens if heartworms are left untreated in Washington?

Untreated heartworm disease is fatal. Adult worms grow up to 12 inches long inside the heart and pulmonary arteries, causing progressive heart and lung damage. Dogs with heavy worm burdens develop congestive heart failure within 1–3 years. In Washington, heartworm prevention costs $140/year — about 8% of what treatment costs. Prevention is the clear choice.