Louise Round, a marine animal medic, explained that “seal finger” is caused by the necrotic bacteria on their teeth. She said: “It’s a really nasty blood infection, it’s horrible.

Seal finger infections are caused by different kinds of Mycoplasma bacteria, which live naturally in the mouths of sea mammals like seals and sea lions, according to a 2009 published case report.

Before antibiotics, seal finger, also known as sealer's finger and spekk-finger (from the Norwegian word for blubber), was a serious threat to hunters or people handling untreated pelts. They ...