graham law wrote: Has anyone out there had similar experience with Bayvarol/Apistan treatments? If there is anything in this suspicion then Spring treatments should be avoided if not absolutely necessary. see http://www.nalusda.gov/ttic/tektran/data/000009/21/0000092180.html and http://www.nalusda.gov/ttic/tektran/data/000009/83/0000098333.html