This drug is carefully administered intravenously through a series of injections. This treatment does potentially have many side effects. This appears to be a much safer approach to treatment of the disease and has fewer side effects. A few days after treatment, the worms die and are carried by the bloodstream to the lungs where they lodge in small blood vessels. There they decompose and are absorbed by the body over a period of several months.
Fatalities resulting from treatment are rare among dogs that are otherwise in good health.
The patient should be given a thorough physical and laboratory exam prior to treatment. These tests should include a blood count, blood chemistry analysis, and a chest x-ray as a minimum data base. Any other problems that might cause complications should be corrected before heartworm treatment begins. Following treatment, complete rest is required to prevent lung damage from the dead and decomposing worms. Excitement and exercise should be avoided for at least a month, followed by gradual return to normal activity.