What is the cycle of a heartworm, and how will this information be beneficial to my cat? - Animal Hospital of Statesville

The heartworm cycle in a cat is when a mosquito bites the cat and injects a baby worm into the cat’s skin. These worms then migrate through the skin into the bloodstream, and they arrive at the lungs, and that's when all the damage is done. Months later, when the worms start arriving at the lungs, the cat develops an intense inflammatory reaction to destroy these worms before they continue to mature. The cat has these asthma-like symptoms—coughing, open mouth breathing, vomiting, and labored breathing in general.