What are the End stages of heart worms in dogs?

The end stages of heartworms in dogs, known as severe heartworm disease, occur when a large number of adult heartworms reside in the heart, lungs, and associated blood vessels. This can lead to significant cardiovascular damage, pulmonary hypertension, and organ failure. Symptoms may include severe coughing, difficulty breathing, lethargy, weight loss, and fluid accumulation in the abdomen. Without prompt treatment, end-stage heartworm disease can be fatal.