April is Heartworm Awareness Month, and at Bark Avenue Daycamp, we want to ensure our dog boarding, dog training, doggie daycamp, and dog grooming clients are aware of what heartworm disease is, what the warning symptoms are, and how to test for, how to treat and prevent heartworm disease in their dogs and puppies.
What is Heartworm Disease?
Heartworm, also known as Dirofilaria, is a serious and potentially fatal disease found in the hearts of dogs. And dirofilaria immitis is a large worm that causes heartworm disease. The heartworm’s life cycle can take 6-7 months to complete, at which time the worm can reach up to a foot in length. The American Heartworm Society has published a video on YouTube that covers the Heartworm life cycle in great detail. At the end of the life cycle, the heartworm can live for several more years in the heart and pulmonary vessels, where it clogs the heart causing less blood to push out to the rest of the body which can lead to heart failure.
How Dogs Get Infected With Heartworms
Mosquitoes are the main carrier of heartworm disease. A single bite of an infected mosquito carrying the parasitic worm, dirofilaria immitis, can put your dog at risk for developing heartworm disease. It is not spread directly from dog to dog.
The Effects of Heartworms on a Dog
Heartworm disease can clog the heart and major blood vessels leading from the heart, including the pulmonary artery, also interfering with the function of the heart’s valves. With the obstruction of blood flow, the clogging of main blood vessels to organs is reduced, particularly the lungs, liver, and kidneys – causing these vital organs to malfunction. Signs of heartworm disease depend on the number of adult worms present, the location of the worms, the length of time the worms have been present in the dog, and the degree of damage that has been sustained by the heart, lungs, liver, and kidneys.
Warning Symptoms of Heartworm Disease
Heartworm disease in dogs can be a silent killer because it can take months before your dog shows symptoms. In the early stages of infection, most dogs show little to no symptoms at all; as the disease progresses, the more likely symptoms will develop. At Bark Avenue, we monitor our dog daycare and kennel boarding clients for any abnormal symptoms that could be a sign of possible underlying disease or sickness, and we ensure to report those concerns to our dog owners.
Even if your dog is on preventative heartworm medication, it’s still important to recognize the signs of this disease, so you can seek treatment as soon as possible in the unlikely event that your dog gets heartworm.
According to the FDA, there are four stages of heartworm disease, and symptoms appear differently in each stage:
- Class 1: No symptoms or mild symptoms such as an occasional cough.
- Class 2: Mild to moderate symptoms such as an occasional cough and tiredness after moderate activity.
- Class 3: More severe symptoms such as a sickly appearance, a persistent cough, and tiredness after mild activity. Trouble breathing and signs of heart failure are common. For class 2 and 3 heartworm disease, and heart and lung changes are usually seen on chest X-rays.
- Class 4: Also called Caval syndrome. There is such a heavy worm burden that blood flowing back to the heart is physically blocked by a large mass of worms. Caval syndrome is life-threatening and quick surgical removal of the heartworms is the only treatment option. The surgery is risky, and even with surgery, most dogs with caval syndrome are fatal.
Diagnosing Heartworm Disease
In most cases, one or more simple blood tests will diagnose heartworm disease, which detect antigens produced by the adult female heartworm. This is why testing usually starts around 7 months of age. Further diagnostic tests are often required in heartworm-positive dogs to determine if the dog can safely undergo heartworm disease treatment. Some or all of the following diagnostic procedures are recommended before treatment is started:
- Bloodwork (complete blood cell count, serum biochemistry). Blood tests may also be recommended prior to the treatment of heartworm disease, in order to assess for the presence of heartworm-associated organ damage.
- Serological test for antigens to adult heartworms (antigen test, ELISA). This test is performed on a blood sample. It is the most widely used test because it detects antigens (proteins) produced by adult heartworms.
- Radiographs (X-rays). Radiographs are often recommended in dogs with heartworm disease, to assess the extent of heart and lung damage present prior to beginning treatment.
- Echocardiography. An ultrasonic examination is used to see into the heart chambers and even visualize heartworms.
When To Test a Dog for Heartworms
Dogs should be routinely tested for heartworms during preventative vet visits. Puppies under the age of 6 months can receive their first heartworm prevention medication, without undergoing a heartworm test, since it takes 6 months for a dog to test positive for heartworms after its been infected. However, you should take your puppy to receive heartworm testing again 6 months afterward, then once a year to guarantee they continue to test negative for heartworms.
Adult dogs over the age of 6 months who haven’t taken preventative medication should be tested for heartworms, before beginning a year-round preventative regimen, then testing again six months later, then once a year to guarantee continued negative tests for heartworms.
Preventing Your Dog from Getting Heartworms
Make sure you are taking your dog to the vet for regular checks ups at least once every year. Your vet will be able to perform a full physical and check for signs and symptoms of heartworms. If you are looking for dog care near me and are in need of a veterinarian in the Bartlett, Illinois area, you can check out our list of recommended Animal Hospitals.
You will want to use preventative heartworm medication that is provided by your veterinarian that will ward off and kill heartworm larvae if it ends up infecting your dog.
It is essential to keep your dog on a year-round administration of heartworm prevention medication. There are many options, not only used for prevention but are also effective against other parasites such as roundworms, hookworms, fleas, and tapeworms. Here is a list of some common heartworm prevention medications: