08/03/2026
๐ฆ Heartworm Disease: It Only Takes One Mosquito Bite
Did you know that heartworm disease affects both dogs and cats? While it's more common in dogs, cats are also at risk even if they live indoors.
In New Hampshire, an average of approximately 388 heartworm-positive cases are reported each year, reminding us that heartworm is present here and prevention matters.
โค๏ธ What causes heartworm?
Heartworm disease is caused by the parasite Dirofilaria immitis and is spread only through the bite of an infected mosquito. It is not contagious between pets. Once inside the body, the worms can grow and live in the heart, lungs, and blood vessels, causing serious and sometimes life-threatening damage.
๐ถ Signs in Dogs
โข Persistent cough
โข Fatigue or reluctance to exercise
โข Weight loss
โข Difficulty breathing
โข In severe cases, heart failure or collapse
๐ฑ Signs in Cats
Heartworm disease is harder to diagnose in cats and may cause:
โข Coughing or asthma-like symptoms
โข Vomiting
โข Difficulty breathing
โข Lethargy
โข Sudden collapse or, in rare cases, sudden death
Even a single heartworm can make a cat seriously ill, and unfortunately there is no approved treatment to eliminate heartworms in cats.
๐ก๏ธ The Best Protection Is Prevention
The good news is that heartworm disease is preventable. Monthly or long-acting heartworm preventives are safe, effective, and much easier than treating the disease after infection. Year-round prevention is recommended for both dogs and cats.
๐ Have questions about the best heartworm prevention for your pet? Our team at Meredith Animal Hospital is here to help keep your furry family members healthy all year long.