Pudding was heartworm positive, successfully treated and adopted through Homeward Trails.
Coco was an upbeat, loving ten-year-old beagle when Homeward Trails Animal Rescue – a Northern Virginia-based rescue organization – took her under their wings.
Sue Bell, founder and owner of Homeward Trails, was eager to whisk Coco away from her previously lonely, uncomfortable (at best) life in a rural southwestern Virginia town. First, the Homeward Trails team would treat Coco for her multiple health issues, and then they would find her a loving owner in Northern Virginia who would finally give her the home and life that she deserved.
“Coco had the sweetest personality,” Bell recalled. “She came to us from rural Virginia, where clearly she had been neglected her entire life. Among so many preventable health problems, she had a heavy load of heartworms. Still, despite all her pain, she was a tail-wagging bit of sunshine. Sadly, she succumbed to the heartworms. She suddenly started coughing up gobs of blood, the oxygen level in her blood plunged, and despite the veterinarian’s efforts, she didn't make it.”
Coco’s tragic story is a cautionary tale. While she was one of many dogs with heartworm – a mosquito-borne illness – who have come into the care of Northern Virginia rescue organizations over the past decade, she has also been one of the few that Bell has seen die from the disease.
Bell established Homeward Trails in 2001, and through the non-profit organization, her team pulls animals from low-income shelters, owners who cannot provide for them, and from other unfortunate situations. They then place their rescues into loving, permanent homes – primarily in the Mid-Atlantic.
Through her journey with animal rescue, Bell has discovered that heartworm disease is entirely preventable – and usually treatable when caught early (and even when caught not so early).
“With the thousands of dogs we’ve treated over the course of 21 years, we have a 99.99% success rate with heartworm,” Bell said. “Of thousands of dogs, we’ve lost less than ten to heartworm complications. The overwhelming majority of our dogs with the disease go on to live happy and healthy lives.”
This statistic, though, hinges on awareness of heartworm disease and taking necessary actions as early as possible.
What Is Heartworm Disease?
Heartworm disease is a mosquito-borne parasitic infection that impacts dogs, cats, and other animals, and it is every bit as unpleasant as its name indicates. While heartworm disease can infect a host of mammals, canines are the most commonly infected.
For dogs who have not been treated with prevention medication, heartworm disease is a relatively common disease. The infection is “caused by foot-long worms (heartworms) that live in the heart, lungs, and associated blood vessels of affected pets, causing severe lung disease, heart failure and damage to other organs in the body,” according to the American Heartworm Society.
Through just one bite, a mosquito can inject the larvae of parasitic worms directly into a dog’s body. These larvae travel through the bloodstream and settle into the dog’s heart, vessels, and lungs, where they grow and multiply. Over the course of six to seven months, they fully mature into worms that can be up to one foot long. Tangled up and taking up precious real estate in a dog’s vital organs, the parasites cause life-threatening, painful inflammation.
“Dogs are the natural host for heartworms and they can reproduce and survive in a dog,” Dr. Matt Novarr, DVM, veterinarian at Columbia Pike Animal Hospital, said. “Since cats, for example, are an atypical host, the worms do not progress into adulthood within them, and they only tend to have a few worms at a time if they do get an infection.”
On the other hand, dogs can ultimately host up to hundreds of worms (though the average is around 15). These worms can live within a dog between five and seven years.
Testing is required to confirm heartworm because dogs don’t always exhibit symptoms – at least not for some time.
“The cycle of heartworm, once bitten, takes about six months to get it and test positive,” Bell said. “Symptoms may take a while to present in a dog, and include excessive coughing, panting, or having a round belly that can be mistaken for pregnancy. Heartworms clog the arteries of the heart, and oftentimes there are no outward indications of this. Largely, we do not see physical signs. It takes a blood test – usually combined with other tests.”
Heartworm disease is rare in dogs who begin their lives in Northern Virginia, but it is more common to find the parasite among animals who come to local organizations from more rural locations.
“Because the DC area is such a hub for the importation of animals from other areas, there is a relatively high prevalence of heartworm,” Bell said. “Where pet owners in Northern Virginia are resourced both in terms of education about heartworm and in the ability to procure resources for preventing it, people in other areas are not in the same position.”
Dr. Novarr’s firsthand observations align with Bell’s experience with the disease.
“Heartworm is present in Virginia, but tends to be more common down south,” he said. “It has been present here since I began practicing in 2008, and the majority of cases we get are from dogs that are adopted from more southern states. I am not an expert on the epidemiology of heartworms, but generally anything that would increase the amount of mosquitos would potentially lead to a higher incidence of heartworms.”
Bell attributes the rise of animal rescue as a “growing business” in Northern Virginia to the increased awareness and lower instances of heartworm in the area.
“I would think we know more about it because the business of animal rescue and sheltering has grown so much,” Bell said. “I think that’s thanks in part to some of the very large animal associations. For the last 20 years, those organizations have been doing a lot of communication and outreach to the public about homeless animals. Millions and millions of dollars have gone into animal rescue and welfare. At one time, millions of animals were dying in shelters needlessly, and in the last few years, more and more people have been getting dogs from these places. Decades ago, it was far more common that you’d buy a dog from a breeder.”
Peoples’ ability and unequivocal willingness to invest in their animals’ health and wellbeing – to treat them with the same priority as with human family members – also translate to better heartworm statistics in Northern Virginia.
“Once people have pets, research has proven over and over again that care for animals is inelastic for people in areas like ours,” Bell said. “On the other hand, this – along with animals being a big, big business and the awareness of heartworm – doesn’t translate to rural areas.”
Bell said that the way so many dogs live in rural southern areas contribute to making conditions ripe for the spread of heartworm disease.
“I can tell you behaviorally that dogs are generally more sedentary than cats and other animals,” Bell said. “While the dogs we see with heartworm are varied in their breeds, the largest breed of heartworm-affected breeds we see are hounds and beagles. So many of them are owned by hunters or other people who house them outside year-round. These dogs are sitting ducks, often on chains and living in small pens outdoors, 24/7/365.”
Even though heartworm prevention is legally considered critical care, Bell said that the pets she pulls from under-resourced shelters – namely in southern Virginia and West Virginia – are just not getting the treatment.
“These outdoor dogs are also not being given preventative medication,” Bell said. “This is oftentimes because of barriers – both financial and otherwise – for pet owners to obtain preventative care. A lot of people in under-resourced areas do not understand what heartworm is. There is that educational deficit. Even then, prevention would be cost prohibitive, where it really isn’t a financial issue in places like Northern Virginia.”
“DON’T BE SCARED” Adopting or fostering a dog with heartworm disease
According to animal rescue experts in Northern Virginia, heartworm disease – which is not transmittable to humans – should not deter potential fosters or adopters from bringing home infected dogs.
“Don’t be scared to adopt a heartworm dog,” Bell said. “It is the exception to rule that there will be long-term complications. I am living proof – one of my own dogs had heartworm. The treatment was manageable for both of us and now she is a completely normal dog.”
Chelsea Jones, Senior Communications Specialist for the Animal Welfare League of Arlington (AWLA), agreed with Bell – based on what she’s seen at AWLA and also from her experience adopting her own beloved previously heartworm-positive dog.
In her dog’s case, heartworm treatment was a bit more complicated. Still, she said that even though supporting her dog, Obie, through the process could be overwhelming at times, she couldn’t be happier that she didn’t let the diagnosis stop her from adopting him.
"I knew Obie was heartworm positive when I adopted him, and I was also lucky that I knew more about the disease than another dog owner might because of my 11 years in animal sheltering,” Jones said. “Despite some difficult nights and a long period of rest, pills, shots, testing, and some more pills, Obie is heartworm free and living his best life. I don't regret adopting him or going through treatment with him; this guy is my little shadow and I would do anything for him. My only regret is that I can't time travel to make sure he was getting his heartworm preventative so he didn't have to go through it all.”
The key to beating and overcoming heartworm, as emphasized by both Bell and Jones, is early testing and timely treatment – and then the consistent administration of monthly prevention treatment to dogs throughout their lives.
“If a dog tests positive for heartworm, we follow American Heartworm Association protocols,” Bell said. “These have varied, but have always involved some dosage of doxycycline [an antibiotic], a heartworm preventative medication, and injections of Immiticide. There are various ways to do it, but it’s usually some kind of combination of these treatments. And it usually works.”
Jones said the AWLA follows a similar course of action, adding that a dog who is treated for heartworm must lay low while in recovery.
“This can vary from case to case, dependent upon the severity of the infection, but the standard in-shelter treatment for heartworm is a dose of ivermectin (heartworm preventative), then 30 days of doxycycline, then another dose of ivermectin, as well as the first dose of melarsomine,” Jones, the AWLA’s Senior Communications Specialist, said. “Thirty days later they get two more melarsomine shots, 24 hours apart. During this time they get prednisone and other medications as needed. From start to finish, treatment takes about four months. The animal has to be on strict exercise restriction the entire time, and for another eight weeks after their last injection.”
Acknowledging the limited exercise requirement, Bell insisted that caring for a dog in the midst of heartworm treatment is still absolutely manageable.
“It’s keeping your dog somewhat calm for a relatively short time after treatment,” Bell said. “People think that means a dog has to be in a crate 24/7, but that’s not the case. They can go out on slow, leisurely walks. While it’s harder when you have young, energetic dogs, in the grand scheme of things, the time it takes for them to undergo treatment is nothing to blink at.”
Dr. Novarr noted that there is never an official time that it becomes “too late” to treat a dog with heartworm disease.
“I wouldn't say that it is ever too late to treat, but as the patient develops a more severe infection, there can be secondary changes to the heart and lungs and the treatment would be more difficult,” he said. “There would be a higher risk of side effects secondary to more numerous dying worms as well as changes to the heart and lungs.”
He said the main issue with intensive heartworm treatment is that it can be costly.
Fortunately, because rescue organizations in Northern Virginia do not often face the same resource challenges as their counterparts in other areas, it is pretty standard for local groups – including Homeward Trails and the AWLA – to pay for the entire course of treatment for every infected animal.
Prevention: The best heartworm strategy
According to the Federal Drug Administration, heartworm testing should be conducted on all dogs who are seven months and older.
The American Heartworm Society also recommends that dogs be tested for heartworm annually.
Then, once a dog has tested negative for the disease – whether it is post recovery or he or she has never had heartworm – owners should always be diligent about prevention measures – no matter where they live. After all, while it is less common in areas of high elevation and in the northeastern part of the US, heartworm has been detected in all fifty states.
“Thankfully, prevention is very easy,” Jones said. “All dogs (and indoor and outdoor cats) should get a monthly preventative heartworm medication – commonly a tablet – along with their flea and tick preventative treatment. Talk to your vet if you aren't sure if your monthly preventative covers heartworm.”
Monthly prevention is a non-negotiable for pet health, even in Northern Virginia’s coldest months.
“Heartworm prevention not only prevents heartworm, but some other intestinal parasites – some of which may be contagious to humans,” Dr. Novarr said. “It is also much cheaper to prevent heartworms and intestinal worms than it is to treat infections once they are present. Typically heartworm preventatives aren't very cost prohibitive, but there are always less expensive options that can be discussed if cost is the main concern.”
He added that preventing one dog from getting heartworm can translate to safeguarding many dogs in a community against heartworm.
“Mosquitoes can pick up the infection from other dogs who are infected, then spread it to different dogs if they aren't on their prevention,” Dr. Novarr said. “So by using the heartworm preventative, you are helping to protect other dogs as well.”
Heartworm disease is a serious disease that results in severe lung disease, heart failure, other organ damage, and death in pets, mainly dogs, cats, and ferrets. It is caused by a parasitic worm called Dirofilaria immitis. The worms are spread through the bite of a mosquito.What do you need to know about heartworms? ›
Heartworm disease is a serious disease that results in severe lung disease, heart failure, other organ damage, and death in pets, mainly dogs, cats, and ferrets. It is caused by a parasitic worm called Dirofilaria immitis. The worms are spread through the bite of a mosquito.What is an interesting fact about heartworms? ›
Heartworms Are Spread by Mosquitos
Parasitic worms are often thought of as being caused by consuming raw or rotten meat. However, heartworms are actually spread by mosquitos, which take little larvae into their body when they bite an infected animal.
Prognosis: heartworm treatment success rates
With the three-dose adulticide protocol described above, in conjunction with doxycycline and macrocyclic lactones as recommended by the American Heartworm Society, 98% of dogs will be cleared of heartworm infection.
Dogs with heartworm disease can live high-quality lives as long as they are given appropriate care. After completing treatment and following your veterinarian's recommenda- tions on heartworm disease testing and prevention, the chances of any long-term effects are very low.Can my dog jump on the couch after heartworm treatment? ›
There is no reason to allow running, jumping, or other physical activity at any time for 8 weeks after the start of the injectable heartworm adulticide treatment.Are heartworms hard to get rid of? ›
No one wants to hear that their dog has heartworm, but the good news is that most infected dogs can be successfully treated. The goal is to first stabilize your dog if he is showing signs of disease, then kill all adult and immature worms while keeping the side effects of treatment to a minimum.What do heartworms live off of? ›
The mosquito plays an essential role in the heartworm life cycle. Adult female heartworms living in an infected dog, fox, coyote, or wolf produce microscopic baby worms called microfilaria that circulate in the bloodstream.How long do heartworms live? ›
Once mature, heartworms can live for 5 to 7 years in dogs and up to 2 or 3 years in cats. Because of the longevity of these worms, each mosquito season can lead to an increasing number of worms in an infected pet.Where do heartworms go after they are killed? ›
After treatment, the adult worms die and are carried by the blood to the lungs where they lodge in small blood vessels. There they decompose and are absorbed by the body over a period of several months.
As they break up, they are carried to the lungs, where they lodge in the small blood vessels and are eventually reabsorbed by the body. This resorption can take several weeks to months, and most post-treatment complications are caused by these fragments of dead heartworms.How many treatments does it take to get rid of heartworms in dogs? ›
Treatment Requires a Vet's Help
Once a positive test is confirmed, our veterinarians (in alignment with the American Heartworm Society) recommend treating adult heartworm infections with 3 treatments (injections) of a drug called melarsomine.
With heartworm disease treatment can be extremely difficult even for the young otherwise healthy dogs but our senior dogs can see more severe side effects and death if progressed disease is present. Know that 1 in 10 dogs will develop some form of heart disease as they age.Do dogs feel bad with heartworms? ›
Dogs with heartworm infections will feel weaker, and will find it harder to remain active, even in low-energy activities. Weight loss and loss of appetite. In more advanced stages of heartworm infections, your dog will find it hard to complete normal physical tasks like eating.What should your dog not do for awhile after heartworm treatment? ›
“No running, jumping, playing or high-impact exercise as these activities may cause the worms to break loose and cause significant harm to the pet being treated.”Is heartworm damage permanent? ›
Heartworm Disease Causes Lifelong Damage.Will dogs poop out heartworms? ›
Myth #3: If my pet has heartworms, I will see them in her feces. Although many worm types, such as roundworms and tiny hookworms, are shed in your pet's feces, heartworms do not live in the gastrointestinal (GI) tract, and are not found in feces.Can dogs go on walks during heartworm treatment? ›
Most dogs can be safely leash-walked during the treatment recovery period and providing appropriate chew toys can help relieve some of that stored up physical energy.Do I have to crate my dog after heartworm treatment? ›
It means cage rest! Your heartworm positive dog, after receiving melarsomine treatment will be instructed to remain caged, crated or penned for the duration of this phase of treatment except when they need to go outside to potty or when you can absolutely-positively-guarantee that your dog will remain calm.How much does it cost to get rid of heartworms? ›
Though there are treatments to fight heartworm disease, it's not always easy to rid your dog of the infection. It's estimated heartworm treatment costs anywhere between $600 to $6,000. Even more, heartworms cause long-lasting complications even after they're gone.
Slow Kill Method
While not generally recommended, another method of handling heartworms is to only attack the microfilaria, leaving existing adult heartworms to die of natural causes. This is known as the slow kill method. It's cheaper and does not require a rest period and debilitating adulticide.
Dogs that have a high number of heartworms often develop symptoms such as pronounced and persistent coughing, difficulty breathing, and exercise intolerance. In more severe cases, dogs may also experience fainting or collapse, pale mucous membranes, weakness, elevated heart rate (tachycardia) and severe lethargy.What is Stage 4 heartworm in dogs? ›
Stage 4 – Heartworms have caused severe damage to the animals heart, lungs, liver, and kidneys. In this stage, Caval syndrome is likely. Caval syndrome is when there is such a large amount of worms blocking blood flow to the heart that it creates a sudden life-threatening problem in need of quick surgical intervention.What to do if you can't afford heartworm treatment? ›
If owners can't afford treatment at the time of diagnosis, Dr. Herrin recommended delaying melarsomine therapy but still initiating treatment with both a preventive and doxycycline. This will prevent further infection and remove the dog as a heartworm reservoir.Can heartworms live in humans? ›
In the United States, heartworm infection in dogs and humans are endemic in the east and southeast regions. It is believed that the organism is inoculated into humans via a mosquito bite. From there the microfilaria migrates into subcutaneous tissues, where they mature for 80–120 days.Can a heartworm positive dog be around other dogs? ›
As mentioned above, the infected blood is carried by affected mosquitoes from host to host. This means that if your dog is located in close proximity to another heartworm infected dog, the chances could be higher for your dog to be infected. They cannot be spread from one pet to another pet directly.Can heartworms cause sudden death? ›
A complication of heartworm infection, known as caval syndrome, leads to shock-like symptoms and sudden death.What months are heartworm most common? ›
April is Heartworm Prevention Month, and there are important reasons veterinarians across the United States promote heartworm prevention this month and throughout the year. While the risk of heartworm is more prevalent in spring and summer when there are more mosquitos, a pet can get heartworm any time of year.How do dogs get rid of dead heartworms? ›
The adult worms die in a few days and start to decompose. As they break up, they are carried to the lungs where they lodge in the small blood vessels and are eventually reabsorbed by the body.Do heartworms come out in vomit? ›
Finally, frequent vomiting usually goes along with heartworms. Dogs who cough often may cause themselves to vomit as a result of their extensive coughing. Some dogs may feel nauseated from their heartworms as well, and may vomit often just because they feel so sick with the disease.
In fairly rare cases, heartworms can migrate to the eyes and brain which causes neurological symptoms including: Blindness.Can dogs cough up dead heartworms? ›
Discussion. Hemoptysis (expectoration or coughing up of blood) has been reported as a consequence of severe heartworm infection in dogs,2-6 although it remains a relatively uncommon finding. Even fewer reports exist of dogs coughing up or vomiting up adult heartworms.Why is my dog crying after heartworm treatment? ›
The medicine in the treatment (Immiticide) can cause a lot of inflammation at the injection site. This can occur no matter how smoothly things go and how little it seems to bother the dog at the time. This can range from being absolutely undetectable to a dog that is crying constantly with pain.How painful is heartworm treatment for dogs? ›
The only product currently available for the treatment of adult heartworms is melarsomine dihydrochloride (immiticide). During treatment, the patient receives an intramuscular injection deep in the lower back muscles. This is a painful injection and it is common for the patient to be quite sore at home afterwards.How are dead heartworms expelled? ›
Unlike intestinal parasites, however, which, once killed, can simply be passed in the animal's stool, heartworms, once dead, do not have an easy way to be eliminated from the body. The dog's immune system must break down the dead worms, an elimination process which is very effective but does take some time.How do I keep my dog quiet during heartworm treatment? ›
- Keep dogs from running up and down stairs.
- Stop brisk, long walks and replace with shorter, leisurely walks.
- Put away the fetch ball.
- Crate all dogs before answering the door.
- Do not allow games of chase.
- Minimize how much jumping up/down off furniture happens.
In most cases no reaction of any kind occurs when an ivermectin-based heartworm preventive is given to a heartworm positive dog. In fact, giving an ivermectin-based heartworm preventive to an infected dog is the first step in heartworm infection treatment.Do pumpkin seeds get rid of heartworms in dogs? ›
Pumpkin seeds are an extremely effective deworming agent because they contain an amino acid called cucurbitacin. This paralyzes the worms making them easily eliminated from the intestine. They can be fed whole as a treat or you can grind them into a fine powder and add to Fido's food.How to get rid of heartworms in a dog without going to the vet? ›
They can be controlled naturally with citrus oils, cedar oils, and diatomaceous earth. Dogs needing conventional treatment may benefit from herbs such as milk thistle and homeopathics such as berberis; these minimize toxicity from the medications and dying heartworms.How much apple cider vinegar do you give a dog for heartworms? ›
Unlike other vinegar, apple cider vinegar increases the alkaline levels in the intestines of the dog. As a result, it creates an inhospitable environment for worms and other parasites. You can add ¼ to 1 tsp of apple cider vinegar in your dog's water daily.
Six months after they bite your dog and inject those larval microfilariae heartworms into your dogs, it takes that six months for them to develop into that adult worm. So generally, it's anywhere from six to 12 months after they've been bitten; you may start noticing signs in your pet.Can my dog jump on couch during heartworm treatment? ›
There is no reason to allow running, jumping, or other physical activity at any time for 8 weeks after the start of the injectable heartworm adulticide treatment.Can my dog go up and down stairs after heartworm treatment? ›
Strict rest is imperative for 6-8 weeks. This means that your pet can be leashed walked outside to urinate and defecated, but must come back inside to rest. Do not allow your pet to run, jump, climb stairs, or play rough with other dogs or children.Do dogs poop worms after heartworm treatment? ›
You may be surprised to still see live worms in your dog's feces after deworming them, but this is normal. While this can be an unpleasant image, it's actually a good thing — it means the worms are no longer living inside your dog!What is the lifespan of a dog with heartworms? ›
The lifespan of a dog in this condition is most likely limited to a few weeks or a few months. Your vet will guide you on the best course of action for treating your dog depending on the severity of their infection. Dogs can live for at least six to seven months after becoming infected with heartworms.How long does it take a dog to recover from heartworm? ›
There should be no physical activity for 6 weeks or until cleared by the veterinarian. No play, no running. Active dogs that have a hard time resting after treatment, may be prescribed calming meds during recovery. The recovery period is a great time to train the brain.How long does it take to get rid of heartworms in a dog? ›
Heartworm treatment is a process carried out through 4-6 months. During heartworm treatment the patient must stay confined while the heartworms are dying off to prevent embolisms and other health risks.Can humans get heartworms from a dog? ›
You can't get heartworms from your dogs, cats, or other pets — only from mosquitos that carry the infection. Most heartworm microfilariae die on their way through the skin. Even if they do get into your blood somehow, heartworms can't mature and will eventually die off.What are the first signs of heartworms in dogs? ›
Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss. As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen.What should I watch out for heartworm treatment? ›
Treatment for heartworm can cause serious complications for your pet's health and can be potentially toxic to the dog's body. Many dogs experience soreness and swelling at the site of their injections. The most severe side effects are related to a large number of worms suddenly dying.
Since the mosquito is needed to carry the microfilariae, heartworm disease is not contagious from one dog to another dog. People also cannot get heartworms from dogs. Dogs and humans can only get heartworms from infected mosquitos.How long can a dog have heartworms before showing symptoms? ›
Six months after they bite your dog and inject those larval microfilariae heartworms into your dogs, it takes that six months for them to develop into that adult worm. So generally, it's anywhere from six to 12 months after they've been bitten; you may start noticing signs in your pet.How do dogs feel when they have heartworms? ›
Dogs that have a high number of heartworms often develop symptoms such as pronounced and persistent coughing, difficulty breathing, and exercise intolerance. In more severe cases, dogs may also experience fainting or collapse, pale mucous membranes, weakness, elevated heart rate (tachycardia) and severe lethargy.What time of year do dogs get heartworm? ›
Spring time is notoriously known as “heartworm season” for many pet owners as well as “flea and tick season”. There is truth to this! Springtime is when all of the creepy crawlies begin to come out of their hibernation and start infecting our pets (and sometimes us!) to start their lifecycles.What months do dogs get heartworm? ›
We recommend starting your pet on heartworm medication June 1st and continuing until November 1st. In some areas such as the Southern USA, heartworm prevention is necessary year-round. This is very important to remember if you are travelling to a southern location in the winter.What not to do with a heartworm positive dog? ›
Your veterinarian is going to advise you that your heartworm positive dog should not do activities that keep the dog's heart rate elevated. This means your heartworm positive dog should not run, jump, sprint, go for long walks, play chase, fetch, have zoomies, run up and down the stairs, and the like.Can my dog walk around the house during heartworm treatment? ›
Most dogs can be safely leash-walked during the treatment recovery period and providing appropriate chew toys can help relieve some of that stored up physical energy.Are dogs with heartworms in pain? ›
Is heartworm painful? - Animal Hospital of Statesville. It's not painful, per se, but they feel sick, uncomfortable, and they're likely having difficulty breathing. They're not perfusing very well, so they don't feel well.What happens after a dog is treated for heartworms? ›
After treatment, the adult worms die and are carried by the blood to the lungs where they lodge in small blood vessels. There they decompose and are absorbed by the body over a period of several months.