The adult heartworm lives in the right chamber of the heart and pulmonary artery that routes blood through the lungs where carbon dioxide is removed and oxygen is added to the red blood cells.
Infected hearts sometimes, become so full of worms that only a trickle of blood can get through.
Mosquitoes are the main carriers of the disease.
A single mosquito bite may imply a heartworm infection.
Mosquitoes bite an infected dog and pick up some microfilaria from the blood meal.
The microfilaria lives for about two weeks in the salivary glands of the mosquito.
When the mosquito bites a dog or a cat, it punches a little hole with some pinchers.
It then releases some saliva which prevents the blood from clotting.
As the mosquito starts sucking blood, some microfilaria finds their way into the wound.
The microfilaria then begins to migrate through the tissue following veins to the heart.
As the larva migrates, they molt and continue growing in size (insects have a rigid exterior, they need to molt or shed the exterior to grow in size).
This process takes about six months in order to reach the adult size in the heart.
Then, they begin giving birth to offspring, the microfilaria.
The whole process then continues and is repeated over several times.
The offspring cannot grow into adults without coming out of the animal and spending time with the mosquito at cooler temperatures.
In other words, a mosquito is necessary.
If it releases one microfilaria into the wound, only one adult heartworm would lodge in the body of the pet.
The more times the pet is stung by infected mosquitoes, the more heart worms they acquire.
Treatment for heartworms in cats has a 70% treatment fatality rate.
Symptoms are controlled with drugs such as steroids and antibiotics.
Heartworm treatment in dogs is possible but it is very risky and expensive.
The number of heartworms extant in a dog's body can alter the outcome of treatment drastically.
Since treatment is risky or sometimes even fatal, prevention is the best course of action.
If you are in an area with mosquitoes, it is advisable that your dogs and cats take heartworm prevention.
