Unless there are a huge number of worms (as in a dog that has died from the disease, which would be the picture at the top of the post), they really aren't in the heart , but rather in the pulmonary arteries, those vessels coming from the right side of the heart to the lungs (to get oxygen).  If the dog is athletic and active, a more turbulent flow of blood is generated in the arteries by the higher blood pressure and more rapid heart rate.  This beats up the inside of the arteries by whipping the worms around.

The blog below has more details on where we are at and I really do hope to say more by the end of the week. Every little helps and I appreciate £50 is far too much for most but hopefully £50 man will do his bit. It doesn’t even need to be a donation as a voucher purchase helps with cash flow too. I’m certain that once open the support will be there as it was with the Fruitmarket Gallery exhibition but this last bit is proving tricky. 

The microfilariae circulate in the bloodstream for as long as two years, waiting for the next stage in their lifecycles in the gut of a bloodsucking mosquito. When ingested by a mosquito, the microfilariae undergo a series of molts to the infective third larval stage, and then migrate to the salivary glands of the mosquito, where they wait to infect another host. The incubation period required to reach the stage where the microfilariae become transmittable to another host can be as little as two weeks or as long as six weeks, depending on the warmth of the climate, and the larval lifecycle ceases entirely if the ambient temperature drops below 14°C (57°F).

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