We took our 2 yr old sister Yorkies to the emergency room last night after applying Advantix - they were walking with their back end to the side and their back legs were weak. They are still having problems and we are applying Viatmin E oil to them - the vets bathed them to get rid of as much as they could. Still are a little lethargic but are eating ok. Has anyone had this problem and what Flea and Tick meds do you suggest?