How long does it take for immature dog heartworm stages to reach the heart?

The correct timeframe for immature dog heartworm stages, specifically the larvae, to reach the heart is between 90 to 120 days. After a dog is infected with heartworm larvae from a mosquito bite, it takes several months for the larvae to mature, migrate through the bloodstream, and ultimately establish themselves in the heart and pulmonary arteries. This duration is crucial for understanding the lifecycle of heartworms and the timing of treatments or preventive measures. Recognizing that this maturation period falls within the 90-120 day range underscores the importance of consistent heartworm prevention, as animals may not show symptoms until the worms have developed significantly.