Using a 25mg pill, you'd give 1-2mg per pound of body weight....so for your kiddo, that would be 5.5-11mg. So, that'd be 1/4-1/2 of that pill. If there *was* ever a major sting, I would not hesitate for a millisecond in giving the larger dose.
In emergencies, keep in mind that pills can be tougher to force down - so you may also want to keep the Childrens Liquid Benadryl (or generic is fine) on hand. For that, the dose comes as 12.5mg/5 ml (which also translates to 2.5mg/1 ml). Per my Vet Dermatologist, the dose for UP TO a 10lb dog is 1 tsp....so for yorkies, I'd consider a dose of 1/2-1 tsp depending upon whether the situation is emergent.
Does that all make sense?
Also, here is a link for making a doggie ER kit:
http://www.yorkietalk.com/forums/sic...g-dosages.html