Even small amounts of alcohol (after all, cats are pretty small) can cause a range of nasty symptoms if your cat manages to take a drink. (preventivevet.com)
Unfortunately, many dried versions contain lots of chemical food preservatives that can cause nasty symptoms like itching or swelling. (bembu.com)
There's another factor that contributes to the widespread belief that teething causes nasty symptoms, and that's confirmation bias. (slate.com)