The immature worms» arrival into the
small arteries in the lungs initiates a severe inflammatory response that damages not only the arteries, but also the bronchioles (small airways) and alveoli (air sacs where gas exchange in the lungs takes place).
Vessels commonly blocked
include arteries in the lungs, which cause rapid breathing or panting, rapid heart rate and high body temperature, and the iliac arteries (which supply the back legs), which causes a blockage called a saddle thrombus, with sudden paralysis of the rear limbs.
For instance, many doctors routinely prescribe a powerful blood thinner called warfarin to prevent a pulmonary embolism, a potentially deadly blood clot that blocks
an artery in the lungs.
According to one study on mice, NAC can thus cause pulmonary arterial hypertension (PAH) at high doses, a dangerous disease when
the arteries in the lungs narrow and lung blood pressure rises.
The worms grow and multiply, infesting the chambers on the right side of the heart and
the arteries in the lungs.
Once they have established themselves in the dogs blood stream they migrate to
the arteries in the lungs, there they will continue to grow causing serious lung inflammation, eventually leading to heart failure.
The immature worms then enter a blood vessel and are carried to
the arteries in the lung where they cause an inflammatory reaction.
The larvae migrate to
arteries in the lungs and parts of the dog's heart, where they are able to feed freely and develop into adult heartworms.
A pulmonary embolism can be deadly because it blocks
the artery in the lung, cutting off the blood supply completely.
Pulmonary embolism can occur when a blood clot in the leg — called a deep vein thrombosis — breaks free from the location in the leg, travels through the blood and blocks
an artery in the lung.
Pulmonary Embolism:
The arteries in the lungs are blocked, usually by a blood clot that has traveled from other areas of the body.