Heartworms are a type of parasitic organism that lives inside the heart and lung arteries of cats and dogs and grows by feeding on the surrounding blood. It’s an easily preventable, yet very costly and difficult disease to treat. In some severe cases, the parasite can grow to around 30cm long and around 2cm thick, with a population of more than 200 individuals. Heartworms offspring are also known as Microfilariae and can be found throughout the infected pet’s blood.
How does it spread?
Heartworm is spread via mosquitoes and can only affect cats and dogs. When a dog gets bitten by the infected mosquito, the larvae migrate through its body until they reach the heart and lungs. This process takes around six months and when they are fully mature the heartworms will start reproducing. If a mosquito bites an infected dog it can easily pick up Microfilariae and once they develop transfer them into another dog, continuing the heartworms life cycle.
Can people be affected?
Heartworm is a very specific parasite and can only affect mammals such as cats, dogs, wolves, foxes, coyotes, raccoons, ferrets, bears and some reptiles. The majority of human infections suspected to be heartworms have actually been caused by a closely related parasite, but there have been a few cases proven to be heartworm infections.
Can it be transferred from one dog to another?
This disease is only transferred via infected mosquitos. Even if a mosquito were to bite an infected dog and then bite another dog that same day, the parasite wouldn’t be transferred to the healthy dog. The heartworm needs to go through an incubation period inside the mosquito before it can be transferred to another animal.
What are the symptoms?
There are no symptoms during the initial stage of the disease. But as worms keep reproducing and growing inside the heart and lungs, the dog develops a dry and often times a persistent cough. Other symptoms include:
- Lack of stamina
- Inability to exercise
- Weight loss
- Dry coat
In the most severe cases, abnormal lungs sounds can be heard and some dogs will even pass out due to a loss of blood flowing to the brain.
Detection and treatment
There is a number of different products you can use for heartworm prevention like popular Advocate for dogs. It should always be given to dogs living in endemic regions, where the risk of developing this disease is at its highest.
If your veterinarian is suspecting heartworm disease, he will perform the necessary tests to establish the severity of the disease. He may use an electrocardiogram to detect disturbances in the heart rhythm or an enlarged right heart ventricle, and order additional tests such as blood and urine analysis, and an X-ray.
During the initial treatment, the pet is hospitalized and given adulticide, which is designed to eliminate adult worms. After that, a heartworm treatment for dogs includes a monthly prophylaxis which can be given at home. In some cases, a dog may have clots forming inside the blood vessels which tend to break off and travel through the blood and clot a completely different vessel. Situations such as these would require longer hospitalization times and in the most severe cases, surgical treatment.
Heartworm prevention should begin when the puppies are at least 3 months old. If your dog is older than three months, the veterinarian will have to perform some blood tests in order to check whether your dog is free of heartworm. The reason behind this is that the prevention therapy can produce some nasty side effects if given to an infected dog.