Heartworm Life Cycle Mosquitoes carry heartworm larvae and transmit them through biting. When a dog or cat is bitten by a heartworm carrying mosquito, the larvae travel through the bloodstream until they reach the pulmonary arteries and heart (this takes 3-4 months). Once the larvae reach there destination they begin the 3 month process of maturing and producing more larvae. Heartworm larvae can survive in the bloodstream for up to 2 years.                                                    Why Heartworm Prevention is so important........ Adult worms in the pulmonary arteries or heart cause inflammation as well as thickening of the blood vessel walls. Blood pressure then increases to compensate for the thicker blood vessel's movement through the cardiac system. This can lead to heart failure. See how big of a threat heartworm disease is in your area from Idexx (click here). Interactive maps require Flash version 8 or above.   Symptoms Coughing, difficulty breathing, vomiting, weight loss, fatigue, and sudden death.   Treatment Heartworm treatment is risky, lengthy, and expensive! A total of eight visits are required in order to treat the parasite as well as control symptoms. The patient will undergo x-rays, lab work, multipleinjections, day and overnight hospital stays, and weekly progress exams and parasite screening. In advanced cases it is possible that health will not be fully restored.   Prevention Heartworm prevention is simple, safe, and effective. All the animal needs is a heartworm test once a year to obtain prescription preventative medication. Ask the knowledgeable staff at Animal Medical Service about which products are best for your pet.