Researchers have discovered captive killer whales are likely suffering from toothaches as painful and distracting as they are for humans.
The international research team included a scientist from the University of Otago, which found 100 percent of the orcas examined had damaged teeth.
"We found that more than 65 percent possessed moderate to extreme tooth wear in their lower jaws, mostly as a result of chewing concrete and steel tank surfaces," Stetson University's Professor John Jett said.
The researchers found that more than 61 percent of the orca they studied had their teeth drilled to remove the soft pulpy tissue inside.
However the hole is not filled or capped and is instead left open for the rest of the animal's life.
"Once the tooth gets worn to the point where the pulp is exposed this opens up a channel for disease and infection, so the staff then drill the teeth," University of Otago's Dr Carolina Loch says.
Another scientist involved in the research, Dr Jeff Ventre adds that once a tooth is drilled, the tooth is much weaker and is prone to fractures.
"Teeth damage is the most tragic consequence of captivity, as it not only causes morbidity and mortality in captive orcas, but often leads to chronic antibiotic therapy compromising the whale's immune system," he said.
"We have documented more than 60 percent of the second and third teeth of the lower jaws were broken and this high number is likely linked to the drilling."
Dr Ventre adds during his time as a whale trainer he also witnessed whales breaking their teeth on steel gates while jaw popping.