When it comes to protecting your dog from heartworms, knowledge is key. In this article, we will provide you with all the information you need to understand what heartworms are, how dogs get them, the symptoms, diagnosis, and treatment of heartworm disease, and how you can prevent it.
Heartworm disease is a serious and potentially life-threatening condition that affects the lungs and heart of dogs. It is caused by an infection of tiny worms that are transmitted by mosquitoes. Heartworm disease is a preventable condition, but if left untreated, it can cause severe and irreversible damage to your pet’s health.
The good news is that you can protect your dog from heartworm disease with the right preventative measures. In this article, we will go over all the essential information you need to know about heartworms and how to keep your dog safe.
How Do Dogs Get Heartworms?
Heartworms are parasitic roundworms that can infect all sorts of critters like cats, foxes, coyotes, wolves, and yes, dogs too. Dogs in particular are extremely vulnerable to heartworm infection because they often spend time outdoors (close to the other potential carriers) and often come into contact with mosquitoes.
Heartworms spread by first infecting the mosquitoes that feed on the blood of an infected animal. When a mosquito bites a heartworm-infested animal, the heartworm larvae (called microfilaria) transfer to the mosquito. Once there, they wait for the insect to take its next meal—your dog.
When an infected mosquito bites your dog the heartworm larvae transfer once again.
This is how your dog gets heartworms. The larvae then live in your dog's bloodstream as they grow and mature. Eventually, they migrate to your dog's critical organs like the heart and lungs. And finally, after about 6 months of growth, this is where mature heartworms can cause life-threatening damage.
Want to be even more creeped out? If not dealt with, these parasites can live for 5 to 7 years in your dog after reaching maturity.
Where do heartworms come from?
According to the Centers for Disease Control and Prevention (CDC), heartworms are most common in the southeastern United States where mosquito populations are the most dense. However, heartworms are a potential threat anywhere mosquitos and pets can be found together. Although they are more common in some regions over others, about 1.5% of all dogs in the United States are infected with heartworms.
What are the Symptoms of Heartworms in Dogs
Dark tarry stool
Swelling of the abdomen
The most common symptom of heartworm disease that we see in dogs is a cough. This happens when worms block arteries in the lungs. Other symptoms include difficulty breathing, weight loss, lethargy, and loss of appetite. In severe cases, heartworms can cause fatal heart failure.
Be on the lookout for changes in your dog. One of the earliest signs of heartworm disease in dogs is lethargy, or acting tired and “lazy.” Additionally, if you notice your dog suffering from shallow and rapid breathing, they have a reluctance to exercise, or they get easily fatigued from moderate exercise (when they didn't before), schedule an appointment to see a vet. Other signs to look out for are a persistent decrease in appetite and weight loss.
If the disease goes untreated, your dog may suffer from heart failure, an excess amount of fluid in the abdomen which gives them a massively swollen belly, or a sudden block of blood flow in the heart marked by a sudden onset of labored breathing, pale gums, and dark bloody or coffee-colored urine.
It's hard to imagine a scarier health issue. Heartworms are a real threat, with real consequences.
It’s also important to note that some dogs may not show any symptoms of heartworm infection. This is why regular heartworm disease testing is important.
Diagnosing Heartworm Disease in Dogs
If your dog is showing any of the symptoms of heartworm disease, your vet will likely recommend a heartworm test. This is a simple blood test that detects adult worms and can provide a diagnosis for pets with severe symptoms of heartworm infection. Any infection over 6 months old (which is when symptoms would begin anyway) will show up in the results.
The test involves taking a sample of your dog’s blood and sending it to a lab for testing. Results usually take a few days to come back. If the test is positive, your vet will recommend a course of treatment.
Treatment for Heartworm Disease in Dogs
If your dog tests positive for heartworm disease, your vet will recommend a course of treatment. This usually involves a combination of anti-parasitic drugs and lifestyle changes.
The medication used to treat heartworm disease is designed to kill adult worms. Vets will often also suggest a monthly preventative medication, such as a monthly oral chewable or topical solution. Not only does this kill adult worms, but it will also help to prevent future infestations.
If your dog does get heartworm, early treatment is key to preventing or reducing damage to the major organs. This usually involves a combination of both adulticide and microfilaricide drugs. Adulticide drugs to kill adult heartworms; microfilaricide drugs to kill immature worms. This combination ensures (as best as possible) the extermination of the pests.
In most cases, the vet will also suggest exercise restrictions, because physical activity can make your dog's symptoms worse. I'm sure you can imagine, treatment for heartworm disease can be expensive and time-consuming. Don't want to pay that price (who would)? Then prevention is your best option.
Preventing Heartworm Disease in Dogs
The best way to protect your dog from heartworm disease is to use preventative medication. These medications can be given in the form of pills, topical gels, or injections. They work by killing the larvae before they have a chance to develop into adult worms.
There are a variety of heartworm prevention medications available. Your dog will need to be tested for heartworms before they can take prescription heartworm medication. These can be deadly if your dog already has a worm when they start a prescription. Your vet will be able to run the required tests and recommend the best option for your dog. However, some common heartworm prevention medications include:
Ivermectin: This is a common oral medication that is given once a month.
Selamectin: This is a topical medication that is applied to the skin once a month.
Moxidectin: This is an injectable medication that is given every 6 months.
Imidacloprid/moxidectin combination: This is a topical medication that is applied to the skin once a month.
In addition to preventative medication, you can take other steps to reduce your pup’s risk of contracting heartworm disease. Keep your dog away from areas where mosquitoes tend to congregate, like standing water or tall grass. If possible, avoid walking your dog in areas where mosquitoes are present. Additionally, keep your dog up-to-date on flea, tick, mosquito, and heartworm prevention, as these can all be sources of infection. Flea control options like Advantix or Wondercide (ones that prevent mosquitoes from biting) are great heartworm preventatives in low risk areas like Southern California, don't require a negative heartworm test prior to use, and can be safely used with prescription preventatives for added protection.
Heartworm disease can be a life-threatening condition that affects the critical organs of your dog. It is caused by an infection of tiny worms that are transmitted by mosquitoes. Fortunately, heartworm disease is preventable with the right preventative measures.
In this article, we went over all the essential information you need to know about heartworms and how to keep your dog safe. We discussed what heartworms are, how dogs get them, the symptoms, diagnosis, and treatment of heartworm disease, and how you can prevent it.
We hope this article was helpful in informing you about heartworms and how to protect your dog from this potentially deadly condition. If you have any further questions, please don’t hesitate to contact your veterinarian.