People keep talking about this weapon being a device to euthanize animals but I've also heard talk of other types of weapons. But nothing verifying the claim it truly is a device used by vets. I always like to read comments in the news articles that generate a lot of responses and I really like this response from a person who is very familiar with weapons. From a NYPost article dated December 7, 2024
There are two components to suppressing a firearm. The first is to use "quieter" ammunition which is that below about 1000 fps (varies depending on altitude, humidity, etc.) and the second is to "muffle" the burning gas, like with a suppressor.
The suppressor doesn't (typically) slow down a bullet, so if it is super-sonic, it'll still make the "crack" sound. If you use sub-sonic ammunition, you still have the explosive "pop" of gasses as the bullet leaves the barrel.
For a "silenced" firearm, you need sub-sonic ammunition and a suppressor to muffle it.
And sub-sonic ammunition (like 9mm) uses less powder so the bullet flies slower, but this also means reduced power to cycle the action (fling the slide back) so you either "stovepipe" it requiring clearing, or just won't feed the next round. Either way, you cycle the gun to clear and chamber the next round