It sounds to me that your vet saw you coming and is trying to take you for a ride. You should definitely stand up to him/her and not let them charge you for a bunch of unnecessary stuff. Have your dog's baby teeth pulled while he's being neutered and forget about the dental sealant. If you're brushing his teeth five times a week, he shouldn't have any problems with his teeth or gums later. Let the vet do a heartworm
test, and start your dog on a monthly heartworm pill. I use Iverheart Max, the 12 pound size. My vet told me to break the pill in half and only give half for a six pound dog. This saves me money because the six month supply now lasts a year.
As far as your dog changing after being neutered, I think he'll only change for the better. I've spayed and neutered many, many dogs and none changed for the worse. My yorkie was neutered at 6.5 months and he was fully house broken by then, and has never marked in my house or even lifted his leg outside. He is almost 1.5 years now.
I hope you will learn to stand up to your vet. I think they see you as an inexperienced owner (possibly a young owner too
and it sounds to me like they are charging you way more money than necessary. If the vet keeps this up, don't hesitate to ask questions here. It sounds to me like your vet is charging you for a whole lot of stuff you don't need.
