Contraindicated in dogs hypersensitive to it. The manufacturer warns to only use the oral
product in dogs tested negative for heartworm infection. Adult heartworms and microfilaria
should be removed prior to therapy. If more than two months pass between dosages of this, or
other once a month heartworm preventative medications, the dog should be tested for heartworm
infection before receiving the next dose.
Reproductive studies have demonstrated no evidence of adverse effects on fertility,
reproductive performance, or offspring
