The following adverse reactions have been reported in dogs after administration of milbemycin oxime or praziquantel: vomiting, diarrhea, depression/lethargy, ataxia, anorexia, convulsions, weakness, and salivation.
Prior to administration of Interceptor Plus, dogs should be tested for existing heartworm infections. At the discretion of the veterinarian, infected dogs should be treated to remove adult heartworms. Interceptor Plus is not effective against adult D. immitis. Mild, transient hypersensitivity reactions, such as labored breathing, vomiting, hypersalivation and lethargy have been noted in some dogs treated with milbemycin oxime carrying a high number of circulating microlariae. These reactions are presumably caused by release of protein from dead or dying microlariae.