I run an automotive shop and I get people coming in wanting diagnostics on their vehicle and then want to supply their own parts. I flat out say “no”. I don’t want the headache of having to deal with warranties or the wrong part or anything like that. I also get people calling who did their own diagnostics and want me to install parts. Again I just say “no, might want to try another shop”.

I personally have never ran into the issue the OP had with a vet. The vet I see is fair and helpful with prices if needed. If I did run into the issue, I would just find a different vet and call it a day.

What a lot of people don’t understand is it costs a lot to run any business and trying to just make money off labor aka check ups and stuff just doesn’t cut it unless you overcharge on it to make up for the loss of parts aka medicine.

Anyways, good luck on whatever avenue you take and hopefully the animal gets better as that is the ultimate goal.