Hi All - I've been reflecting and tracing my steps for days now following Coco's episode of anaphylactic shock this past weekend. I had a revelation this afternoon. 1 day before each episode, I had administered her monthly dose of Frontline Plus. Now I've begun to think that this might actually be the cause since I didn't actually see a bug on either occasion. Today I looked it up on the internet and have read of others that have had the same experience using these preventative flea/tick medications. Your insights and perspectives are greatly appreciated. Mama Diane & Little Coco Chanel