Heartgard (Ivermectin) should be administered once a month year-round for the prevention of heartworm disease.
The usual dosage is:
- For dogs up to 11 kg: 68 mcg
- For 12-22 kg: 136 mcg
- For 23-45 kg: 272 mcg
For dogs over 45 kg, a combination of the chewables is recommended.