What are heartworms?
Heartworms are parasites that live in a dog’s heart and pulmonary arteries. The parasites go through a lifecycle that starts when a mosquito bites an infected animal and ingests immature heartworms called microfilaria (source). Inside the mosquito, the microfilaria develop into infective larvae. When the mosquito bites another animal, like a dog, the larvae are deposited on the skin and enter the new host. Once inside a dog, the larvae migrate to the heart and mature into adult heartworms that can reproduce and complete the cycle.
An adult female worm can produce thousands of microfilaria that circulate in the dog’s blood. These microfilaria live for up to 2 years and wait to be picked up by the next mosquito (source). A dog is infected when the larvae from the mosquito develop into adult heartworms living in the heart and pulmonary arteries. It takes about 6-7 months from initial infection for adult worms to develop.
Heartworm disease is very prevalent in dogs. The American Heartworm Society estimates that up to 250,000 dogs in the U.S. and its territories have heartworms. Dogs living anywhere mosquitoes can be found are at risk.
Do heartworms make dogs vomit?
One of the most common symptoms of heartworm disease in dogs is vomiting. Heartworms that infect the heart and lungs can cause inflammation, damage, and disrupt normal circulation. This puts stress on the dog’s body and digestive system.
According to veterinarians, vomiting is seen in about 20-25% of infected dogs as the heartworm disease progresses (source 1). The vomiting may be mild at first but can become more severe and frequent as the heart and lungs become further compromised. In advanced stages of the disease, dogs may vomit up blood.
While vomiting does not occur in every dog with heartworms, it is considered one of the more typical clinical signs. Other common symptoms include coughing, exercise intolerance, weight loss, lethargy, and difficulty breathing. As heartworm disease advances, the symptoms tend to become more noticeable and severe.
So in summary – vomiting in dogs can certainly be caused by a heartworm infection. If a dog is vomiting frequently and the cause is unknown, it is advisable to have a veterinarian run a heartworm test. Catching and treating heartworm early leads to better outcomes for the dog’s health and recovery.
Can you see heartworms if a dog vomits?
Heartworms in dogs are thin, white, thread-like worms that can grow up to 12 inches long as adults. They reside in the dog’s heart and pulmonary arteries. Due to their length and slender shape, spotting an entire adult heartworm in a dog’s vomit would be very rare.
However, it is possible that small pieces or fragments of heartworms could potentially be seen in a dog’s vomit. As heartworms mature in a dog’s cardiovascular system, some parts of the worms may die and break off. These fragments could make their way through the dog’s system and be expelled. According to veterinarians, these fragments may resemble grains of rice or thin strands of spaghetti (Source).
However, the presence of these fragments in vomit does not definitively diagnose a heartworm infection. A veterinarian would need to run specific diagnostic tests. Overall, while it’s possible to see pieces of heartworms in vomit, an entire intact worm would be highly unlikely.
Diagnosing heartworms
When diagnosing heartworms in dogs, vets use a variety of tests to confirm infection. An initial screening typically involves one or more simple blood tests (vcahospitals.com). These look for the presence of adult female heartworms as well as microfilariae, their offspring. The most common is the antigen test, which detects proteins from the adult worms. If the initial screening is positive, further testing may involve:
Blood tests – In addition to screening, blood tests can help determine the severity of infection and how the dog’s organs are functioning, like kidney and liver tests (todaysveterinarypractice.com).
Chest x-rays – These provide images of the heart and lungs, revealing any enlargement or shape changes caused by heartworms. X-rays also show if there are pulmonary hypertension issues or other infections.
Ultrasound – An ultrasound uses soundwaves to create images of the heart’s chambers and major blood vessels. This helps identify issues like heart enlargement and worms in the heart or pulmonary arteries (vcahospitals.com).
With a combination of blood tests, imaging, and clinical signs, vets fully assess the severity of a dog’s heartworm disease before creating a tailored treatment plan.
Treating heartworms
There are medications and surgical procedures used to treat heartworms in dogs. According to the VCA Animal Hospitals, the treatment typically involves administering an adulticide medication to kill the adult heartworms, antibiotics, and steroids over a period of 2-3 months. The medication weakens and kills the adult worms which are then absorbed by the dog’s body over time.
Surgical removal may be necessary in advanced cases where there is blockage of blood flow. This involves either venous bypass surgery to reroute blood flow around obstructed vessels or gradiectomy surgery to physically extract the worms using specialized instruments. Both procedures carry risks of shock, thromboembolism, sepsis, and even death according to the American Heartworm Society.
Other complications can arise during medical treatment as well. As the worms die and break down, they can lodge in the lungs causing coughing, gagging, or pneumonia. Strict exercise restriction and cage rest are required to minimize this risk. There is also potential for adverse reactions to the medications. Close veterinary supervision is crucial throughout the full treatment period which can take many weeks or months until complete recovery.
Recovery process
After heartworm treatment, dogs need strict activity restriction to allow time for the dead worms to be absorbed before they can cause a fatal blockage[1]. Exercise, excitement, and stress must be avoided during the recovery period, which typically lasts 6-8 weeks[2]. Dogs should be kept quiet, only going outside on short leash walks for bathroom needs. Running, jumping, playing, and roughhousing are prohibited. The activity level may then be slowly increased under veterinary guidance.
Follow-up testing is crucial to check for remaining heartworm infection. About 6 months after treatment, dogs should be retested with an antigen test. Additional testing may be done 2-3 months later. If any heartworms are still present, another treatment may be necessary. With successful treatment, most dogs make a full recovery and can resume normal activity after the recovery period. Their prognosis is usually excellent. However, dogs with advanced heartworm disease pre-treatment may have some remaining lung or heart damage that cannot be reversed. But their quality of life still often significantly improves post-treatment.
Preventing heartworms
There are several steps pet owners can take to prevent their dogs from getting heartworms:
Monthly preventatives
Giving your dog monthly heartworm preventative medication is the most effective way to prevent infection. These medications, such as Heartgard, Nexgard, and Revolution, stop the larval heartworms from maturing into adults. Most veterinarians recommend year-round preventatives even in cold winter months when mosquitos are less active, because the medication also stops larvae that may have infected the dog months before from maturing.
Testing
Annual heartworm testing from your veterinarian is an important part of prevention. Even dogs on monthly preventatives should be tested, as it’s possible for a dog to become infected if even one dose of medication is missed. Testing confirms the preventatives are working properly and detects any cases where heartworms have managed to infect the dog.
Mosquito control
Limiting your dog’s exposure to mosquitos helps reduce the chances of getting infected in the first place. Keep your dog indoors during peak mosquito times like dawn and dusk. Use mosquito repellents approved for dogs when spending time outdoors, and make sure there is no standing water in your yard where mosquitoes breed.
Living with heartworms
For dogs diagnosed with heartworms, the impact on quality of life depends on the severity of the infestation. In mild cases caught early, dogs may show minimal symptoms and continue to live an active lifestyle with some precautions.
However, dogs with moderate or severe infections will likely face more activity restrictions. Exercise needs to be strictly limited to restricted leash walks to avoid overexertion that could worsen the condition. High energy activities like running, jumping, or playing fetch must be avoided. This can be challenging for active dogs accustomed to regular exercise.
The prognosis for dogs living with a heartworm infection varies greatly. With proper care and treatment, many dogs go on to live happy lives. But in severe advanced cases, dogs may face a poor prognosis even with treatment. For this reason, early diagnosis through regular screening offers the best odds for recovery.
According to the American Heartworm Society, with adequate treatment and follow-up care, about 85% of dogs with heartworm can go on to live normal lives. But the outlook depends on the severity of infection and response to treatment. Close veterinary supervision is crucial for managing heartworm infections and giving dogs the best chance possible.
With diligent prevention using monthly heartworm medication, regular testing, and prompt treatment if infected, most dogs can live a good quality of life despite the risks posed by this dangerous parasite.
Heartworm misconceptions
There are some common myths and misconceptions when it comes to heartworm disease in dogs. One of the biggest misunderstandings is around how heartworms are transmitted. Many people mistakenly believe that heartworms can spread through direct contact between dogs, but this is not the case. Heartworms require a mosquito vector to complete their life cycle. An infected mosquito carries the larvae and transmits it when biting a dog. Dogs cannot pass heartworms between each other or to humans (source).
Another misconception is that heartworm disease always causes noticeable symptoms in the early stages. In fact, dogs in the beginning stages of heartworm infection often show no signs at all. Symptoms like coughing, fatigue and trouble breathing tend to occur in the later stages when the heartworm burden is heavy. But even dogs with advanced infections can appear asymptomatic on the outside (source). This is why regular screening is crucial.
There are also misunderstandings around what heartworm treatment entails. Some people think surgical removal of adult worms is the standard treatment, but most vets actually use a drug protocol to kill the worms safely. The dead worms then get absorbed and eliminated by the dog’s immune system (source).
The takeaway
Heartworm disease is a serious condition caused by the parasite Dirofilaria immitis that can lead to severe lung disease, heart failure, and even death in dogs if left untreated. While the symptoms and presence of adult heartworms can sometimes cause dogs to vomit, vomiting alone is not a definitive indicator of heartworm disease.
The best way to diagnose heartworms is through a veterinary blood test. Once diagnosed, heartworms can be treated with medications that kill the parasites. However, the treatment itself can be difficult on the dog’s body as the dead worms are absorbed. Strict rest and recovery are required.
The key takeaways are:
- Heartworm disease is progressive and life-threatening if left untreated.
- Diagnosis via blood testing is crucial, as symptoms may not appear until late stage.
- Though treatment is hard on the dog, early intervention improves chances of recovery.
- Prevention through monthly preventatives is the best way to protect your dog.
While seeing heartworms in vomit is possible, regular testing and prevention remain the best practices for protecting your dog against this dangerous parasite.