A Comprehensive Pet Owner’s Guide
Heartworm disease remains one of the most serious health threats facing dogs across the United States today. With over 1.2 million infected dogs nationwide, understanding how this preventable disease spreads and how to protect your beloved pet has never been more critical. This comprehensive guide will answer your most pressing questions about heartworm transmission, prevalence, prevention methods, and treatment options.
Is Heartworm Contagious Between Dogs?
The Truth About Heartworm Transmission in Canines
One of the most common misconceptions among dog owners is that heartworm disease can spread through direct contact between pets. The straightforward answer is no—heartworms are not contagious from dog to dog through physical interaction, shared food bowls, or playing together in the same space.
Heartworm disease cannot spread through:
- Direct physical contact with infected dogs
- Sharing water or food bowls
- Playing in the same yard or dog park
- Contact with infected dog’s feces or saliva
How Dogs Actually Get Heartworm: The Mosquito Connection
Heartworm transmission requires a specific vector—mosquitoes. The life cycle begins when a mosquito bites an infected animal and ingests microscopic heartworm larvae called microfilariae. Over the next 10 to 14 days inside the mosquito, these larvae mature into infective stage larvae. When that infected mosquito bites another dog, it deposits these mature larvae onto the skin surface, where they enter through the bite wound.
Once inside a new host, the larvae migrate through the dog’s body over approximately six months, eventually reaching the heart and lungs where they mature into adult worms. These adult heartworms can grow to an alarming 12 inches in length and survive for five to seven years inside your dog’s cardiovascular system.
Can Humans Get Heartworm From Dogs?
Pet owners can rest assured that humans cannot contract heartworm disease from their infected dogs. Both dogs and humans can only acquire heartworm infection through infected mosquito bites. While extremely rare human infections have been documented, they develop differently in humans and typically result in small lung lesions rather than the severe cardiac complications seen in dogs.
Life Cycle of Heartworm in Dogs
Stage One: Infection Begins With a Mosquito Bite
The heartworm life cycle begins when a mosquito feeds on an infected animal and ingests microscopic larvae called microfilariae from the bloodstream. Inside the mosquito’s body, these larvae develop over 10 to 14 days into infective third-stage larvae. Temperature plays a crucial role in this development—the process only occurs when temperatures remain above 57°F (14°C).
At least 30 different mosquito species can transmit heartworm disease, making prevention essential regardless of your location. When an infected mosquito bites a dog, it deposits the infective larvae onto the skin surface, where they enter through the bite wound.
Stage Two: Migration and Maturation Inside the Dog
Once inside their new canine host, the infective larvae begin an extraordinary journey through the dog’s body. The entire process from initial infection to sexually mature adult heartworms takes approximately six to seven months.
Timeline of Heartworm Development:
Days 1-70: The larvae migrate through tissues and blood vessels, undergoing two molts to reach the immature adult stage approximately 50 to 70 days after infection
Days 70-120: The young adult worms enter the bloodstream and travel to the heart and pulmonary arteries, arriving as early as 70 days post-infection
Months 4-6: By four months after infection, worms in the pulmonary arteries measure 10-15 centimeters in length
Month 6-7: Fully mature adults reach their maximum size at approximately 6.5 months—males grow to 15-18 centimeters while females can reach an impressive 25-30 centimeters
Stage Three: Adult Worms Establish Residence and Reproduce
Adult heartworms reside primarily in the pulmonary artery and adjacent large blood vessels. Female worms are significantly larger than males, and a single infected dog can harbor anywhere from just a few worms to over 300 in severe cases.
Adult heartworms can survive for five to seven years inside a dog’s cardiovascular system, and mature females begin producing microfilariae approximately six to seven months after the initial infection. A single female heartworm can produce millions of offspring during her lifetime, ensuring the cycle continues.
Stage Four: The Cycle Continues
Microfilariae circulate throughout the dog’s bloodstream, with numbers peaking during morning and evening hours when mosquitoes are most active. These microscopic larvae cannot develop into adult worms without first passing through a mosquito host—they will eventually die and disintegrate if not picked up by a feeding mosquito, but adult females continuously replace them with fresh offspring.
When another mosquito feeds on the infected dog, it ingests microfilariae along with the blood meal, and the entire life cycle begins anew. This explains why heartworm disease spreads so effectively in areas with large mosquito populations and why a single infected dog poses a threat to all dogs in the neighborhood.
The Critical Importance of Understanding the Life Cycle
Understanding this complex life cycle reveals why consistent monthly prevention is absolutely essential. Heartworm preventives work retrospectively, killing larvae that infected your dog during the previous 30 days before they can mature into adults. This is why even a single missed dose can be dangerous—it creates a window during which larvae can develop beyond the stage where preventives remain effective.
Pathogenesis: How Heartworms Damage Your Dog’s Body
The Vascular Damage Begins Early
Many dog owners mistakenly believe heartworm damage only occurs once worms reach the heart. In reality, damage to the pulmonary arteries and smaller lung vessels begins occurring even before clinical signs appear. Understanding how heartworms cause disease helps explain why prevention is so much better than treatment.
Mechanisms of Heartworm-Induced Damage
Direct Physical Trauma
Live heartworms injure the pulmonary endothelium through direct mechanical trauma as they move within blood vessels. Imagine foot-long parasites constantly moving inside delicate blood vessels—the physical damage alone is substantial.
Inflammatory Response
The presence of heartworms triggers attraction of macrophages, granulocytes, and platelets to sites of endothelial damage, creating a proinflammatory environment. This inflammation leads to endarteritis (inflammation of the inner arterial lining) and perivascular cuffing, where inflammatory cells, especially eosinophils, accumulate around affected vessels.
Living heartworms cause pulmonary endothelial damage, villous proliferation, and activation of white blood cells and platelets. Over time, this chronic inflammation results in thickening and hardening of blood vessel walls.
The Wolbachia Factor
Recent research has revealed an additional pathogenic mechanism. Heartworms harbor an endosymbiont bacteria called Wolbachia pipientis, which plays an important role in the pathogenesis and immune response to heartworm infection. When microfilariae die and release Wolbachia bacteria, they stimulate additional immune responses that contribute to pneumonitis and glomerulonephritis.
Progressive Vascular Remodeling
Long-term infections result in chronic vascular remodeling, subsequent scarring, progressive endothelial dysfunction, and pulmonary hypertension. The blood vessels essentially become damaged pipes—thickened, less elastic, and unable to function properly.
This vascular damage results in progressive reduction of elastic properties of vessel walls and consequent loss of distensibility, meaning the vessels can no longer expand and contract normally with each heartbeat.
The Death of Worms Causes Additional Damage
Paradoxically, dead and dying heartworms cause even more severe vascular reactions than living worms, inducing thrombosis, granulomatous inflammation, and villous inflammation. When worms die—whether naturally or through treatment—they break apart and these fragments can lodge in smaller vessels, causing pulmonary thromboembolism (blood clots in the lungs).
Pulmonary Hypertension and Heart Failure
As vascular damage accumulates, pulmonary hypertension develops, forcing the right side of the heart to work harder to pump blood through damaged, narrowed vessels. This increased workload leads to compensatory right heart enlargement.
Eventually, the damage to pulmonary endothelium and vascular occlusion reduces cardiac output, and the resulting pulmonary hypertension may progress to right-sided heart failure. The heart simply cannot keep up with the increased demands created by damaged blood vessels.
Activity Level Amplifies Damage
Active dogs tend to develop pulmonary hypertension more often than inactive dogs for any given heartworm burden. Exercise increases blood flow velocity through already-damaged vessels, creating additional shear stress that further damages the endothelium. This creates a vicious cycle where endothelial damage leads to increased flow velocity, which causes more damage, resulting in local ischemia and eventually irreversible interstitial fibrosis.
Caval Syndrome: The Most Severe Pathogenic Event
In caval syndrome, heartworms migrate backward from the pulmonary arteries into the right ventricle and atrium, and sometimes into the vena cava. This occurs when:
- Pulmonary vascular resistance increases dramatically from worm burden and vessel damage
- Forward blood flow is reduced, allowing worms to move backward toward the heart
- Worms interfere with the tricuspid valve, causing both valve regurgitation and inflow obstruction
- Cardiac output falls precipitously, causing acute cardiovascular collapse
Without immediate surgical removal of the worms, dogs with caval syndrome rarely survive.
Systemic Effects Beyond the Heart and Lungs
Heartworms can induce glomerulonephritis and protein in the urine due to antigen-antibody complex deposition in the kidneys. Heartworms may also damage the liver through the body’s reaction to their presence in other blood vessels.
Leakage of plasma and inflammatory mediators from small vessels and capillaries causes parenchymal lung inflammation and contributes to the cough that develops in infected dogs.
Clinical Signs of Heartworm Disease in Dogs: Recognizing the Warning Signals
The Four Stages of Heartworm Disease
Veterinarians classify heartworm disease severity into four distinct stages, each with progressively worse symptoms. Understanding these stages helps dog owners recognize when their pet needs immediate veterinary attention.
Class 1 (Mild Disease): Silent or Minimal Symptoms
Dogs with Class 1 heartworm disease show no symptoms or only mild symptoms such as an occasional cough. Most dogs show little to no clinical signs during early infection, and it typically takes several years before dogs display obvious symptoms.
During this stage, damage is occurring to the pulmonary arteries and smaller vessels even though the dog appears healthy. This is why annual heartworm testing is critical—by the time symptoms appear, significant irreversible damage has already occurred.
Class 2 (Moderate Disease): Exercise Intolerance Emerges
Class 2 heartworm disease produces mild to moderate symptoms including an occasional cough and tiredness after moderate activity. Dog owners often notice their pet seems less enthusiastic about walks or play sessions.
Common Class 2 Symptoms:
- Mild persistent cough, particularly after exercise
- Lethargy and reluctance to exercise, with fatigue developing after activities that previously posed no problem
- Decreased appetite
- Reduced stamina during normal activities
Class 3 (Severe Disease): Obvious Clinical Illness
Dogs with Class 3 heartworm disease display pronounced clinical signs that clearly indicate serious illness.
Class 3 Clinical Signs:
- Persistent dry cough that worsens over time, with shortness of breath, weakness, listlessness, and loss of stamina
- Significant weight loss as the disease makes normal activities like eating difficult
- Difficulty breathing or labored breathing
- Blue or purplish discoloration of skin and gums due to poor oxygen circulation
- Abnormal lung and heart sounds detectable with a stethoscope
All symptoms become most noticeable following exercise, when some dogs may even faint or become disoriented. This happens because the damaged cardiovascular system cannot meet increased oxygen demands during physical activity.
Class 4 (Caval Syndrome): Life-Threatening Emergency
Class 4 represents the most severe and immediately life-threatening form of heartworm disease. Caval syndrome is caused by restricted blood flow to the heart from large numbers of worms.
Caval Syndrome Emergency Signs:
- Sudden onset of labored breathing
- Pale gums
- Dark bloody or coffee-colored urine
- Cardiovascular collapse
- Without prompt surgical treatment, there is a low chance of survival
Advanced Stage Complications
Congestive Heart Failure
As heartworm disease progresses into heart failure, the abdomen and legs swell from fluid accumulation, and dogs develop a distended belly appearance. Other signs include spitting up blood, fainting, and nosebleeds.
Systemic Effects
Heartworms can cause pneumonia, high blood pressure, seizures, and blindness when worms migrate to abnormal locations like the brain and eyes. Weight loss, poor body condition, and anemia frequently accompany advanced disease.
Sudden Death
Severely infected dogs may die suddenly during exercise or excitement. Dogs exposed to large numbers of infective larvae at once face great risk of sudden death as massive numbers of developing larvae bombard the vascular system.
Individual Variation in Disease Presentation
The severity of symptoms varies greatly from patient to patient. Several factors determine how sick an individual dog becomes:
Factors Affecting Disease Severity:
- Worm numbers (burden)
- Host immune response
- Duration of infection
- Host activity level
Active dogs like hunters and performers typically show more dramatic signs than less active dogs, and sedentary dogs may show few or no signs despite harboring many worms. The disease is rare in dogs under one year of age because it takes five to seven months for microfilariae to mature into adults after infection.
Why Early Detection Through Testing Is Critical
Many dogs only show the first visible signs of infection after the disease has progressed to the point where significant damage has already occurred. Heartworm disease in dogs is known as a silent killer because it can take months before symptoms appear.
This silent progression is exactly why veterinarians strongly recommend annual heartworm testing even for dogs on prevention. The blood test can detect infection before clinical signs develop, allowing treatment to begin before irreversible damage occurs. Remember—prevention is always easier, safer, and less expensive than treating established disease.
Heartworm Treatment: Complex and Costly
Why Treatment Is More Challenging Than Prevention
Treating established heartworm infections requires a complex, expensive protocol involving multiple veterinary visits and strict activity restriction over several months. The standard treatment uses melarsomine dihydrochloride, an arsenic-based compound injected deep into the lumbar muscles to kill adult heartworms.
Treatment Protocol Challenges:
- Multiple painful injections administered over weeks to months
- Strict exercise restriction lasting 6-8 weeks to prevent complications as worms die
- Risk of pulmonary embolism from dying worms breaking apart
- Treatment costs ranging from $1,000 to $3,000 or more
- Potential for permanent heart and lung damage even after successful treatment
Long-Term Effects of Heartworm Disease
Even after successful elimination of adult worms, heartworm disease causes lasting damage to the cardiovascular system. Scarring in the pulmonary arteries, heart valve damage, and chronic lung inflammation can affect your dog’s health and quality of life for years after treatment.
This permanent damage is why prevention remains vastly superior to treatment—you cannot undo the harm heartworms inflict on your dog’s body.
How Common Is Heartworm in Dogs Across America?
Heartworm Statistics and Geographic Distribution
Understanding heartworm prevalence helps dog owners assess their pet’s risk level. National estimates indicate that heartworm infections have risen significantly over the past two decades. The number of infected dogs jumped from approximately 800,000 in 2001 to over 1.2 million by 2016, representing a 50% increase despite widespread availability of preventive medications.
Recent data shows heartworm incidence rates increasing in many regions. Between 2013 and 2016, positive test rates rose from 1.11% to 1.28% nationwide, with southeastern states experiencing a 17.9% increase in positive cases.
High-Risk States and Heartworm Hotspots
Certain geographic regions show dramatically higher heartworm prevalence due to favorable conditions for mosquito populations and year-round warm weather. The states with the highest concentration of diagnosed heartworm cases include:
Top Five High-Risk States:
- Mississippi
- Louisiana
- Texas
- Alabama
- Arkansas
The Lower Mississippi River Valley consistently reports the highest heartworm incidence rates in the country. This region’s warm, humid climate creates ideal conditions for mosquito proliferation, while the presence of infected wild canines like coyotes and foxes creates permanent disease reservoirs.
Emerging Heartworm Hotspots in Unexpected Regions
Veterinarians have documented surprising increases in heartworm cases in states previously considered low-risk areas. Washington, Oregon, Kansas, North Dakota, Massachusetts, and Connecticut have all developed new heartworm hotspots. Urban areas including Seattle, Boise, Bismarck, and Tucson have reported significant increases in positive cases.
Heartworm disease has been diagnosed in all 50 states, making prevention essential regardless of geographic location.
Heartworm Medicine for Dogs: Prevention Options That Work
Why Year-Round Prevention Is Essential
The most important fact every dog owner must understand is that heartworm disease is almost 100% preventable with consistent medication use. Prevention represents the safest, most cost-effective approach to protecting your dog from this potentially fatal disease.
Heartworm preventive medications work by eliminating infective larvae before they mature into adult worms. This is why consistent, uninterrupted administration is crucial—even a single missed dose can leave your dog vulnerable to infection.
Types of Heartworm Prevention Medication
Modern veterinary medicine offers multiple effective prevention options, allowing you to choose the method that works best for your dog’s lifestyle and your schedule.
Monthly Oral Preventives (Chewable Tablets)
Monthly chewable heartworm preventives remain the most popular choice among dog owners due to their convenience and palatability. Most dogs readily accept these beef or chicken-flavored tablets as treats.
Popular Oral Preventives:
- Heartgard Plus: Contains ivermectin to kill heartworm larvae plus pyrantel to control intestinal parasites
- Interceptor Plus: Uses milbemycin oxime for heartworm prevention and broad-spectrum intestinal parasite control
- Sentinel Spectrum: Combines heartworm prevention with flea control and intestinal parasite treatment
- Tri-Heart Plus: Generic alternative offering ivermectin-based heartworm protection
Topical Heartworm Prevention (Spot-On Treatments)
Topical preventives are applied directly to the skin, typically between the shoulder blades where dogs cannot lick the medication off. These products offer excellent options for dogs who refuse oral medications.
Topical Options:
- Revolution: Provides heartworm prevention plus flea and tick control in one monthly application
- Advantage Multi: Combines heartworm prevention with protection against fleas, ear mites, and intestinal parasites
Injectable Long-Acting Heartworm Prevention
Injectable heartworm preventives offer the most convenient option by eliminating the need for monthly administration. Veterinarians administer these injections in the clinic, ensuring your dog receives the full prescribed dose.
Injectable Products:
- ProHeart 6: Provides six months of continuous heartworm protection with a single injection
- ProHeart 12: Offers a full year of heartworm prevention with one annual injection
These long-acting injectables particularly benefit pet owners who struggle with medication compliance or have dogs who resist taking pills.
All-in-One Parasite Protection
Combination products provide comprehensive protection against multiple parasites in a single monthly dose, offering exceptional convenience for busy pet owners.
Comprehensive Protection Products:
- Simparica Trio: Prevents heartworms, fleas, ticks, roundworms, and hookworms
- NexGard PLUS: Protects against heartworms, fleas, ticks, roundworms, and hookworms
- Credelio Quattro: Provides protection against heartworms, fleas, ticks, roundworms, hookworms, and tapeworms
- Trifexis: Combines heartworm prevention with flea control and intestinal parasite protection
Choosing the Right Heartworm Prevention for Your Dog
Selecting the most appropriate heartworm preventive depends on several factors including your dog’s age, weight, health status, and parasite exposure risk. Your veterinarian will help you evaluate these considerations:
Key Selection Factors:
- Dog’s age and weight
- Presence of other parasites in your area
- Your dog’s acceptance of oral medications
- Your ability to maintain monthly administration schedules
- Budget considerations
- Concurrent health conditions
The Critical Importance of Compliance
Research reveals a concerning trend—over 68% of dogs leave veterinary clinics without receiving any heartworm preventive medication. This represents a significant increase from 64% in 2009, despite growing awareness of heartworm risks.
Even among dogs prescribed preventives, inconsistent administration undermines protection. Studies show that dogs receive an average of only 8.6 monthly doses per year when 12 doses are required for complete year-round protection.
Heartworm Testing: When and Why It Matters
Annual Testing Recommendations
Even dogs taking heartworm preventives need annual testing to ensure medications are working effectively. Veterinarians can detect heartworm infections through simple blood tests that identify either adult worm antigens or circulating microfilariae.
Testing Timeline:
- Puppies should begin testing at 7 months of age
- Adult dogs on prevention require annual testing
- Dogs with lapses in prevention need immediate testing before restarting medication
Why Testing Before Prevention Is Non-Negotiable
Administering heartworm preventives to an already-infected dog can be dangerous or even fatal. Preventive medications kill circulating microfilariae, which can trigger severe reactions if present in high numbers. This is why all heartworm preventives require a prescription from a veterinarian who has verified your dog’s negative status through testing.
Protecting Your Dog From Heartworm: Best Practices
Year-Round Prevention Strategy
Many pet owners mistakenly believe heartworm prevention is only necessary during warm months when mosquitoes are most active. However, the American Heartworm Society strongly recommends year-round administration of preventives.
Reasons for Year-Round Protection:
- Hibernating mosquitoes can emerge during winter warm spells
- Preventive medications work retrospectively, treating infections from the previous month
- Gaps in protection leave dogs vulnerable to infection
- Missed doses compromise protection and may require retesting
Limiting Mosquito Exposure
While prevention medication provides the primary defense against heartworm disease, reducing mosquito exposure adds an extra layer of protection:
- Remove standing water from your property where mosquitoes breed
- Keep dogs indoors during peak mosquito activity at dawn and dusk
- Use pet-safe mosquito repellents when outdoors
- Install screens on windows and doors to keep mosquitoes outside
- Maintain yard vegetation to reduce mosquito habitat
The Hidden Risk: Heartworm-Positive Dogs Attract More Mosquitoes
Groundbreaking research has revealed that heartworm-infected dogs actually attract more mosquitoes than healthy dogs. Studies show mosquitoes are ten times more likely to feed on infected dogs, wolves, or coyotes compared to uninfected animals. This occurs because infected animals exhale volatile organic compounds from tissue damage caused by heartworms, which mosquitoes can detect and find attractive.
This discovery has profound implications for disease spread—a single heartworm-positive dog in a neighborhood can dramatically increase infection risk for all nearby dogs by concentrating mosquito activity.
Understanding Heartworm Risk Factors
Climate and Environmental Factors
Temperature and precipitation patterns significantly influence heartworm transmission rates. Mosquitoes require temperatures above 50°F (10°C) to actively feed and for heartworm larvae to develop inside their bodies. Warm, humid climates with long mosquito seasons create ideal conditions for disease transmission.
Climate change appears to be expanding heartworm territory into previously low-risk regions as warming temperatures extend mosquito seasons and expand their geographic range.
Wildlife Reservoirs Complicate Control Efforts
Wild canines including coyotes, foxes, and wolves serve as permanent heartworm reservoirs that maintain disease presence in an area even when domestic dogs receive prevention. These animals typically do not receive heartworm treatment, allowing them to harbor and spread infection indefinitely.
The reintroduction of wolves to Yellowstone National Park, for example, correlated with increased heartworm incidence in Montana as wolf packs carried infection throughout their territories.
The Pet Relocation Factor
Transport of dogs from high-incidence areas to low-incidence regions contributes to heartworm spread. Rescue organizations and individuals who relocate heartworm-positive dogs without proper testing and treatment can introduce infection to new areas, establishing disease in communities that previously had minimal heartworm presence.
Frequently Asked Questions About Heartworm Disease
Can indoor dogs get heartworm disease?
Yes, indoor dogs can contract heartworm disease. Mosquitoes easily enter homes through open doors, windows without screens, and other small openings. Even a single mosquito bite can transmit heartworm larvae to an indoor dog, making prevention essential for all dogs regardless of lifestyle.
How long does heartworm prevention last?
The duration depends on the product type. Monthly oral and topical preventives provide 30 days of protection and must be administered on schedule. Injectable products offer six months (ProHeart 6) or 12 months (ProHeart 12) of continuous protection with a single veterinary-administered injection.
Are there natural heartworm prevention alternatives?
No natural products have been proven effective for heartworm prevention. Despite claims you may encounter online or from other pet owners, only FDA-approved medications provide reliable protection against heartworm disease. Using unproven natural remedies instead of prescribed preventives puts your dog at serious risk.
What happens if I miss a dose of heartworm prevention?
Missing a dose creates a window of vulnerability during which your dog could become infected. Contact your veterinarian immediately if you miss a dose. Depending on how long the gap has been, your vet may recommend retesting before resuming prevention to ensure your dog has not acquired an infection.
Can dogs on heartworm prevention still get infected?
While heartworm preventives are highly effective when administered correctly and consistently, breakthrough infections can occasionally occur. This is why annual testing remains important even for dogs receiving regular prevention. Rarely, suspected cases of drug-resistant heartworms have been reported, though this remains controversial and uncommon.
How much does heartworm prevention cost?
Monthly preventive costs typically range from $6 to $15 per dose, or $72 to $180 annually, depending on your dog’s size and the product selected. Injectable preventives cost $50 to $150 per injection. Regardless of the expense, prevention remains dramatically less expensive than heartworm treatment, which can cost $1,000 to $3,000 or more.
Taking Action: Protecting Your Dog Today
Heartworm disease represents a serious but entirely preventable threat to your dog’s health and longevity. With over a million infected dogs in the United States and cases diagnosed in every state, no dog is truly safe without proper protection.
Your Heartworm Prevention Checklist
✓ Schedule an annual veterinary examination with heartworm testing ✓ Discuss the best preventive option for your dog’s specific needs ✓ Administer preventive medication consistently on schedule year-round ✓ Set reminders to ensure you never miss a dose ✓ Keep accurate records of when preventives are given ✓ Reduce mosquito exposure around your home and yard ✓ Watch for any signs of heartworm disease and report them immediately
The Bottom Line on Heartworm Disease
Understanding that heartworms are not contagious between dogs but require mosquito transmission helps you focus protection efforts appropriately. Rather than avoiding infected dogs, the priority should be ensuring your own dog receives consistent year-round preventive medication and limiting mosquito exposure.
With heartworm prevalence rising across the country and cases appearing in previously low-risk areas, complacency is not an option. The excellent news is that this potentially fatal disease remains almost entirely preventable with simple, affordable medications. By making heartworm prevention a non-negotiable part of your dog’s healthcare routine, you provide priceless protection for your beloved companion.
Don’t wait until mosquito season begins or until your dog shows symptoms. Contact your veterinarian today to establish a year-round heartworm prevention plan and give your dog the gift of lifelong cardiovascular health. Your dog depends on you for protection—make heartworm prevention a priority starting now.