my shihtzu adoption

I have read so much info that recommends that small breed dogs not get the lepto vaccine. My dogs are 5.6lbs (biscotti) and 11.4 lbs (isabella). I had Izzy at the vet today to get her 3yr rabies, bordetella, heartworm antigen test and the dhpp shot. After the exam and shots I was at the front desk watching the girl get my receipt ready and I noticed on it was listed Leptovax vaccine. I questioned her on it and told her that I didn't want Izzy to have that and that I was not told she was getting it. She said that it's always given to dogs over 10lbs (Izzy was 10lbs 4oz just last month when she was in for loose stool). I told her that if I would have never agreed to it if I was told about it and that I was only told about the 3 shots. She said that it was included with the adoption of shih tzu.
http://www.shihtzupuppiesforsale.xyz/shih-tzu-adoption/