Heartworm disease is a very serious—and sometimes deadly—condition that can affect any dog, no matter their age, breed, or where they live. Many folks think that only outdoor or country dogs are at risk, but city pups can get heartworms, too. Here at Sibley Animal Hospital, we want to help you understand how to protect your furry friend from heartworms and keep them safe and healthy.

Pesky mosquitoes spread heartworm disease. If a mosquito carrying heartworm larvae bites your dog, those tiny worms can grow up inside your pet’s heart, lungs, and blood vessels. This can cause some very serious health problems, like heart failure and organ damage. The good news? Heartworm disease is almost always preventable with regular care, and it’s much easier to stop it before it starts than to treat it later.

How Heartworm Disease Develops

Heartworm disease begins when a mosquito carrying immature heartworms, called larvae, bites a dog. These larvae travel through the bloodstream and mature into adult worms over several months. Adult heartworms can reach up to a foot in length and live in the heart and major blood vessels. As they grow, they cause inflammation, cardiac tissue damage, and blockages that compromise heart and lung function.

Even city dogs who spend most of their time indoors aren’t off the hook. Mosquitoes can sneak into your home through tiny cracks or open doors and windows. You might not even notice them, but they can still bite your dog. That’s why it’s so important to keep up with heartworm prevention, no matter where you live.

Signs of Heartworm Disease in Dogs

Heartworm disease can progress silently for months before visible symptoms appear. Watch for the following signs:

• Persistent cough or difficulty breathing
• Decreased stamina or reluctance to exercise
• Weight loss or loss of appetite
• Lethargy or fatigue
• Swollen abdomen due to fluid buildup
• Heart murmurs detected during a veterinary exam

Some dogs don’t show any signs at first, which is why regular vet checkups and prevention are so important. Even healthy-looking city pups can have heartworms growing inside, so it’s always best to play it safe.

Heartworm Prevention Strategies

It’s much easier—and safer—to prevent heartworm disease than to treat it after your dog is infected. Here are some simple ways to keep your pup protected:

1. Monthly Preventive Medications

Your vet can prescribe heartworm preventives in pill, topical, or shot form. These meds kill heartworm larvae before they can mature and cause trouble. Giving them on schedule is the key to keeping your dog safe. Not sure which one is right for your furry friend? We’re happy to help you pick the best option for your pup’s age, size, and lifestyle.

2. Annual Testing

Even if your dog is on heartworm prevention, it’s still important to get them tested every year. Catching heartworms early means your vet can start treatment right away and help avoid bigger problems down the road.

3. Mosquito Control

Keeping mosquitoes away from your dog helps lower the risk of heartworm. Here are a few tips:

• Keeping windows and doors screened
• Removing standing water in pots, gutters, or yards
• Limiting outdoor activity during peak mosquito hours

Even in the city, mosquitoes can hang around buildings and yards, so heartworm prevention is still a must.

4. Education and Awareness

Understanding the life cycle of heartworms, seasonal risks, and preventive options empowers owners. Knowing how heartworms spread and when they’re most active helps you keep your dog safe. If you ever have questions, our team is here to help you protect your furry friend all year long. Heartworm prevention:

• Limited outdoor space: Dogs may spend less time in open areas, but can still be bitten by mosquitoes indoors or on short walks.
• Shared environments: Apartment buildings or communal yards increase exposure risk from mosquitoes that have fed on infected animals.
• Travel: Dogs visiting parks, friends’ homes, or other cities may encounter areas with a higher risk of heartworms.

No matter where you and your pup live, keeping up with heartworm meds and yearly tests is the best way to keep them safe.

Treatment Options for Heartworm Disease

If your dog does end up with heartworms, treatment can be tricky and always needs a vet’s help:

• Medication Therapy: Adulticide treatments kill mature heartworms. These treatments may involve multiple injections and strict activity restriction.
• Supportive Care: Dogs with significant symptoms may need additional medications to manage heart failure, inflammation, or secondary infections.
• Surgical Removal: In severe cases, adult worms may require surgical removal.

Since treating heartworms can be tough and risky, it’s always better to prevent them in the first place.

Learn more about heartworms and associated symptoms at the American Heartworm Society here. PetMD has an article explaining the various options for heartworm treatment here.

FAQs About Heartworm Prevention

How often should my dog take heartworm medication?

Preventive medications are usually given monthly, though some injectable options protect for six or twelve months.

Can indoor dogs get heartworm?

Yes. Mosquitoes can enter homes and transmit larvae, so indoor dogs still require prevention.

At what age should heartworm prevention start?

Puppies can typically begin preventive medications as early as 6–8 weeks old, depending on the product and veterinary guidance.

Are heartworm preventives safe?

Yes, when used as recommended by your veterinarian, heartworm medications are safe and effective.

Can I check for heartworms at home?

No. Heartworm infection requires professional blood testing for accurate diagnosis.

Schedule an Appointment at Our Northwest Indiana Vet Clinic

Keeping your dog safe from heartworm disease is one of the best things you can do for their health and happiness. If you have questions or would like to schedule a checkup, give us a call at Sibley Animal Hospital. As your Black-owned Southeast Chicago pet clinic, we’re always happy to help you keep your furry friend healthy and wagging their tail.

This blog is for informational purposes only. Always consult your veterinarian for advice, diagnosis, or treatment plans tailored to your dog.

Want to learn more about Southeast Chicago’s premier Black-owned Veterinary clinic? Stop by our Services page here. You can also check out our Boarding and Grooming page here or our Wellness and Vaccinations page here.