My koda is a 7 month old lab/shepard mix, just got her fixed 2 weeks ago. Housebroken at 3 months, and she is learning heeling and walking without pulling on the leash. She knows, sit, down, leave it, drop it, off, and is getting much better at not jumping up on people. I have been socializing her since i got her around other dogs and people, but today she was INSANE. Pulled up at the vet and another dog was coming out and she went nuts in the car, barking etc. Got her quieted down but when i took her out to go in there were a few more dogs inside and she just went nuts, biting, barking twisting, hackles up, etc had to put her back in the car until the dr could see her. Just a bad day or is she developing serious leash aggression? She is so much better off leash...
It is so discouraging to see your own dog behaving badly in a public place. I feel for you.
Vet offices are kind of unusual places; there are smell of medicines and dogs barking/whining, some dogs/cats and people looking nervous, sometimes crowded, etc.
The other dogs weren't totally relaxed either. Dogs can sense that nervousness and over-react sometimes.
I would recommend Koda to the vet on a weekly basis, without any specific reason but just to get her used to the place. You can just weigh her on the scale, ask the staff to give some treats to her, etc.
I have 3 dogs and they all love vet visits. I take all 3 of them even only one needs to be seen. By visiting there quite often (and every time, I take treats with me), they can be relaxed and behave well. If I see the waiting room too crowded or there are bully kind of dogs, I will wait in the car with my dogs until I find the place pretty manageable.
Don't get too discouraged and stop visiting the vet altogether. Look for a less crowded time and make your visit happy for Koda too
This is a somewhat common problem with young dogs - as MHN said, its just the new smells and multiple animals and sense of everyone else's nervousness, and it can be too much for some animals, resulting in berserk behaviour.
I cant add much, just to agree with MHN's advice to take her every week for a sit down, weigh, treats, and to take it all in and get used to it. Keep it up, it will pay off for sure!!