Heartgard (ivermectin) for Cats should be administered orally at monthly intervals at the recommended minimum dose level of 24 mcg of ivermectin per kg (10.9 mcg/lb.) of body weight. The recommended dosage schedule for prevention of feline heartworm disease and control of hookworm is as follows:
|Cat Weight ||HEARTGARD for Cats |
Chewables per month
|Up to 5 lbs ||1 ||55 mcg |
|5 to 15 lbs ||1 ||165 mcg |
For cats over 15 lb., use the appropriate combination of chewables. Heartgard for Cats is recommended for use in cats 6 weeks of age and older.
Remove only one chewable at a time from the foilbacked blister card. Return the card with the remaining chewables to its box to protect the product from light. Heartgard for Cats can be offered to the cat by hand or may be added to a small amount of cat food. If manual dosing is required, the chewable should be broken into pieces for administration. Food should be routinely available during the day of treatment administration. If cats are fasted, or if the chewable is not broken into pieces for manual dosing, then reduced absorption may result. A relationship between reduced absorption and reduced efficacy has not been established.
Care should be taken to see that the cat consumes the complete dose. Treated animals should be observed for a few minutes after administration to ensure that part of the dose is not lost or rejected. If it is suspected that any of the dose has been lost, redosing with a new chewable is recommended. Fragments of chewables have occasionally been observed in the feces of some cats; efficacy of the product was not adversely affected.
Heartgard for Cats should be given at monthly intervals when mosquitoes potentially carrying infective heartworm larvae are active. The initial dose must be given within a month (30 days) after the cat's first exposure to mosquitoes. The final dose must be given within a month (30 days) after the cat's last exposure to mosquitoes. For optimal performance, Heartgard for Cats must be given once a month on or about the same date. If treatment is delayed, whether by a few days or many, immediate treatment with Heartgard for Cats and resumption of the recommended dosing regimen will minimize the opportunity for development of adult heartworm.
It is recommended that cats should be tested for existing heartworm infection prior to starting treatment with Heartgard for Cats. Cats already infected with adult heartworms can be given Heartgard for Cats monthly to prevent further infections. Monthly treatment with Heartgard for Cats also provides effective removal and control of adult and immature hookworms (A. tubaeforme and A. braziliense).