Please call your vet about this. If you don't have one, get one. Call friends who have pets and ask them who they recommend.
If you can get a 'fresh' sample, take it in to the vet. Use a clean sandwich baggy on your hand like a glove, and pick some up wearing the 'baggy glove'. Then peel off the 'glove' and tie the top tightly.
Please keep us posted on how your kitty is doing.
"Common sense and a sense of humor are the same thing, moving at different speeds. A sense of humor is just common sense, dancing." -- William James