Therefore, it is recommended that a blood test for existing heartworm infection is conducted to assess the pet's current heartworm status, before beginning a prevention program. (primarycarevet.com)
It is important for your veterinarian to assess your dog's heartworm status prior to initiating a monthly heartworm disease preventive, or changing from one brand of preventive to another. (trifexis.com)
Testing such animals 3 - 4 months after initiation of Revolution would be necessary to confirm their negative heartworm status. (medi-vet.com)