Just like us, killer whales can suffer from painful tooth problems, an alarming side-effect of living in captivity. A new study examined 29 captive whales in the US and Spain and found that every single one had dental problems. Orcas have 48 large teeth each, and damage to them is likely to cause just as much pain and suffering as tooth problems do to us. The new findings are published in the journal Archives of Oral Biology.
Since the release of the controversial documentary Blackfish, a wave of criticism towards keeping orcas in captivity has surged. The Blackfish Bill, which illegalized captive breeding of killer whales and orca entertainment shows at SeaWorld in California was successfully passed in 2016. In May this year, France followed suit, banning the breeding of killer whales in captivity.
There are around 60 killer whales in captivity at the moment, in at least 14 marine parks in eight countries. The new research provides concrete evidence that the health of captive orcas is seriously being compromised.
“Every whale had some form of damage to its teeth,” said lead author Professor John Jett from Florida’s Stetson University. "We found that the 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."
Over 61 percent of the whales in the study had reportedly “been to the dentist” to have holes drilled in their teeth. This procedure is called a modified pulpotomy and involves removing the tooth’s soft pulpy tissue.
If we have this kind of treatment at the dentist, the hole gets sealed up. This isn’t the case for the whales. The hole stays open forever, having to be treated with chemicals every day to prevent infections. The drilling weakens the teeth, which can lead to them breaking.
"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," said Dr Carolina Loch, a specialist in whale and dolphin dentition at the University of Otago, New Zealand.
Sadly, the need for daily cleaning of drilled dental holes means that if they were to be rehabilitated in future, captive whales probably wouldn’t be able to be released into the wild.
"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, as we saw recently with the orca known as Kasatka," added co-author Dr Jeff Ventre, an ex-orca trainer turned medical doctor.
Kasatka was an orca at SeaWorld that died from pneumonia earlier this year.
“The results of our study should raise serious concerns for the health and welfare of captive orca," said Jett.