I have a 15 lb bischon who is 3 1/2 yrs old and a new yorkie which is 5 months old she is only 4lbs now but I was wondering if any of you use the electric fence on your yorkie and if it is the petsafe brand?? I was reading on it and it says for dogs 8lbs or over?? I know she is way to small now but I was wondering maybe when she is older if this brand would work on both my dogs please let me know if any of you use this brand and if so what collar you use. Thanks