I'm sorry that your question wasn't answered in a timely manner. Here's the ASPCA synopsis for mum toxicity:
Additional Common Names: Chrysanthemum, Daisy
Scientific Name: Chrysanthemum spp.
Toxicity: Toxic to Dogs, Toxic to Cats, Toxic to Horses
Toxic Principles: Sesquiterpene, lactones, pyrethrins and other potential irritants
Clinical Signs: Vomiting, diarrhea, hypersalivation, incoordination, dermatitis
The toxicity doesn't have a specific antidote and so we treat symptomatically and supportively by giving supplemental fluids by needle if dehydration becomes a problem secondary to loss of fluid from either end of Cutie and we might dose with an antiemetic by needle if vomiting is excessive. In most cases, the tincture of time suffices to normalize cats who ate a few leaves of this mildly toxic plant. Please respond with further questions or concerns if you wish.