It has long seemed that one of the biggest challenges of keeping orcas healthy in captivity is dental care. Many captive orcas wear down and break their teeth by fighting, and chewing on concrete or the gates between pools. If the damage is bad enough SeaWorld and other facilities drill out the teeth and then flush them daily. Even so, the damaged teeth become prone to infection, infections which can lead to serious health problems.
To more fully gauge and understand the extent of this threat, John Jett and Jeff Ventre, two former SeaWorld trainers, along with other researchers, studied dental damage in captive orcas, using photography to catalogue and evaluate the problem. The result, “Tooth Damage In Captive Orcas, which appears in the Archives Of Oral Biology, is a comprehensive, scientific, assessment that reveals how common and extensive tooth damage in captivity really is.
Highlights of the paper include:
- Mouth images of 29 orca held in captivity were evaluated for tooth damage. Individual teeth in the mandible and maxilla were scored for coronal wear, wear at or below the gum line, fractures, bore holes and missing.
- Dental damage was present in all whales examined, and the various pathologies were observed across animals with different durations of captivity, across both sexes, in captive-born and wild-captured whales as well as whales kept in each facility. Dental pathology was especially prominent for mandibular teeth.
- Forty five percent of whales exhibited “moderate” mean mandibular coronal wear, and an additional 24% exhibited “major” to “extreme” wear.
- Bore holes were observed primarily within anterior mandibular teeth, with more than 61% of tooth 2 and 3 and 47.27% of tooth 4 bearing evidence of having undergone the modified pulpotomy procedure.
- Dental damage begins early in a captive whale’s life.
- Both conspecific aggression among captive whales and oral stereotypies such as biting and chewing on concrete and steel tank surfaces likely contributed to the tooth pathology observed.
Keeping any animal captive–especially a highly evolved, free-ranging, top predator–presents unusual health issues, both mental and physical. It is unlikely many marine park visitors suspect that tooth damage is one of the leading health challenges for captive orcas. But this paper makes clear how common the problem is, and how severe the damage can be. That is important, because the more we understand the negative side-effects of keeping animals captive for entertainment, the better we can weigh the ethical question of whether it is justified.
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