Heartworm Prevention: What is Best for Your Dog?6 min read
Heartworm Prevention – Article Summary
- Dogs get heartworms (a parasite) from mosquito bites.
- If your dog begins to age prematurely or has a mild cough, take them for heartworm testing immediately.
- Dogs living in tropical regions are more likely to have heartworm disease.
- People cannot contract heartworm disease. Dogs cannot contract heartworms from other dogs.
- Test your dog for heartworms once a year after 6 months of age.
- In conclusion, choose a heartworm prevention method and offer it monthly.

Heartworms in Dogs
What are Heartworms?
Heartworms are parasitic roundworms that grow to mature and live inside of your dog’s heart, lungs, and blood vessels. This parasite begins as larva and matures within 6 months of life. The heartworm parasite is born, mates, and has offspring inside a dog.
Heartworms can grow up to 12 inches in size. On average, a dog with heartworm disease will also have about 15 heartworms present, but can have as many as 250 present in the body.

Signs Your Dog has Heartworms
Unfortunately, dogs show signs that they have heartworms long after infection. The more heartworms present in your dog’s heart, the faster these signs will be apparent.
If your dog is not on preventive medication and begins to develop a cough, we highly recommend testing your dog for heartworms as soon as possible. Do not attempt to begin treatment on your own.
Early Signs of Heartworm Disease
- Premature aging
- A gray muzzle and forelegs
- A lackluster coat
- Lower energy levels
- A mild dry cough occurs
Late Signs of Heartworm Disease
- Decreased appetite
- Swollen, pear-shaped pot belly
- Abnormal breathing
- Dark urine

How Does my Dog Get Heartworms?
First of all, dogs get heartworms when they are bitten by a mosquito. Mosquitos retrieve blood from a dog infected with heartworms and transfers the heartworm larva to another dog they bite. The heartworms then travel to your dog’s heart and begin to mature.
In warm areas with a lot of mosquitoes, heartworm disease is more common. Unfortunately, several mosquito bites can lead to multiple heartworms inside your dog.

Which Dogs Get Heartworms?
Whether or not your dog contracts heartworm disease is dependent on some key factors. We recommend a heartworm prevention plan for many dogs but especially the following:
- Outdoor dogs
- Dogs living in tropical, warm regions (like areas near the Gulf of Mexico and Southeastern US)
- Traveling dogs headed to warm regions with many heartworm disease cases
- Dogs living with specific mosquito species present in the area
Also, note that people rarely get heartworm disease. Typically, the larvae die by the time they are able to reach the human heart to mature. Dogs cannot contract heartworms from another dog. Only mosquitos can spread heartworm disease.

Heartworm Testing for Dogs
Heartworm tests are completed by veterinarians. By checking your dog’s blood, a veterinarian can see if heartworms have released anything into your dog’s bloodstream. Heartworm tests for your dog take only about 10 to 15 minutes. As a result, annual heartworm tests should not be an inconvenience.
How Often?
You should test your dog for heartworms once every year (every 12 months). If your dog uses heartworm prevention medicine, we still recommend getting your dog tested annually.
When using heartworm prevention medicine, we recommend your dog is still tested annually for heartworms because:
- Your dog may have spit out the medication
- Your dog may have missed some months of medication
- You can get your prescription renewed after testing
- Your dog may have contracted heartworms before beginning the medication
When Should I Begin?
Begin testing around 7 to 8 months of age. If your dog was bitten as a puppy, your dog is old enough for the heartworm larvae to mature at this point.
First of all, have your dog tested for heartworms before beginning preventive medication. In the case that your dog has heartworm larvae present, the heartworms can still persist and produce offspring in your dog’s body. If your dog has a heartworm present and you begin preventive medication, your dog can suddenly go into shock, or the heartworms may continue to mature and reproduce.

Heartworm Preventative Medication
Ordinary worm medication will not kill heartworms. If you decide to buy heartworm preventive medication without a prescription, we recommend some of the following:
- Ivermectin (like Heartgard)
- Milbemycin oxime (Iike Interceptor)
- Selamectin (like Revolution)
Although we recommend you use medications suggested by your veterinarian.
Heartworm preventive medication is applied topically to the skin, or given as an oral tablet. If it is difficult offering your dog pills orally, we also recommend Greenie’s pill pockets. Instead, you can make your own by placing the tablet in a cheese cube or wrapped in meat.
How often should I give my dog preventive medication?
You should give your dog preventive medicine once a month. While using heartworm preventive medicine, it is important to complete testing for heartworms annually. It is also important for the health of your dog to test your dog for heartworms before beginning a preventative plan.

Heartworm Medication Alternatives
Many holistic veterinarians have concerns about the profits associated with preventive medicine and the effect they have on dogs. Heartworm preventive medicine kills heartworm larvae if your dog becomes infected. This medicine cannot treat fully mature heartworms.
Negative Reactions to Heartworm Medication
Heartworm medication is typically only tested for a few weeks, so scientists are unsure about the long-term health effects. Some short-term reactions to heartworm medication include:
- Vomiting
- Convulsions
- Diarrhea
- Anorexia
- Hypersalivation
- And more…

Heartworm Prevention Medication Alternatives
Instead of working with a traditional veterinarian, we recommend working with a local, holistic vet to offer more feedback and advice for heartworm prevention.
Heartworm Prevention Alternatives
Typically, these herbs are used in heartworm alternative treatments. Unfortunately, this treatment can be dangerous to your dog’s health due to the strength and potency of the herbs.
2. Amber Technology – Herbal Cardiovascular Detox for Canines
This prevention method cannot be confirmed to prevent heartworms due to FDA regulations, but the remedy attempts to. This remedy has a steep price, yet has high-quality ingredients like garlic, Hawthorn berries, and Grapefruit seed extract to boost your dog’s immune system and support a healthy cardiovascular system.
3. Reduce Traditional Medicine Based on Regional Climate
If your local area sees snow for half of the year, you can also reduce the number of traditional heartworm prevention medications during the colder months.
4. Repetitive Heartworm Testing
Instead of using any preventive medication, consider testing your dog two to three times a year. In the case that your dog has contracted heartworms, you can begin treatment to kill the heartworms. Furthermore, this route allows you to prevent the buildup of multiple heartworms, and protects your pup from unnecessary chemicals.
Some holistic vets theorize that a healthy dog eating high-quality foods will also have a healthy immune system to fight off any parasitic attacks. By offering your dog a highly nutritious diet, you also support their health and longevity.
6. Essential Oil Mosquito Repellent
You can also combine multiple alternative approaches including the use of an all-natural mosquito repellent. We recommend a mixture of lemongrass, grapefruit, peppermint, and geranium. Add 10-15 drops of each oil in 12 ounces of water or vinegar.

In conclusion, what is best for you and your dog will vary. It is important to stay aware of your dog’s behavior to prevent heartworm disease. Also, use a prevention method of your choice to keep your pet healthy and happy.
Help another reader – which heartworm prevention method works for you?


