When I graduated the cascade was new and few people had even heard of it in practice. It filtered through quickly and now it’s part of automatic thinking about what drug to use when.
So much is it now integrated in to my thinking that I forget why I objected to it at the time.
I dislike monopolies on principle. I will say that some are necessary, but most are there to protect the interests of the holder, and I suspect there was some hard lobbying on this matter.
Prior to this vets had at least a notional freedom to use whatever drug they saw fit in a particular case and circumstances (I say notional because the vet in question would still be accountable for their decision if something went wrong) and generics were commonly used where the licensed form of the drug wasn’t considered any different. However, it was up to the drug company and their marketeers to justify their product over generic rather than using legal compulsion.
Then the cascade came along and made it a criminal offence to use an unlicensed drug where there was a suitably licensed form available. This is even where the two are the same. You have to have clinical grounds for using a generic or unlicensed drug. Relative costs are irrelevant.
The regulation is justified by apologists by saying that it encourages drug companies to continue developing drugs for the veterinary market. Before this, drug patents safeguarded the income of the developing drug company for a certain period after development. Metoclopramide was an example of a drug that had a licensed form, but because it was identical to the human generic that is what most vets used. I think they were in some ways happier times because it helped the vet keep costs as low as possible.
Now we have some companies who see a generic drug, put it through testing, and the law enforces the use of that branded drug. It’s more expensive for the client and less flexible for the vet.
There is no way of knowing its impact on animal welfare, but I suspect it has been a negative effect rather than the positive effect some would have us believe. The cost of some heart medication regimes for example can be breathtaking and I wonder how much is down to development costs and how much is actually down to the legally-enforced “monopoly” that exists?