Kahana And Kenau: Two Orca Deaths Deconstructed

The analysis of how and why orcas die in captivity provides interesting and often surprising insights into how they lived. So orca necropsies (which are the equivalent of human autopsies) can make for interesting reading. However, you need a specialist to interpret their meaning. So when I saw that the FOIA document dump from NMFS that Russ Rector secured contained two full orca necropsies, I sent them on to veterinarian Jon Zern for comment.

Zern is a straight shooter, and always has something interesting to say when asked about marine mammal health issues. Here is a brief summary of his background:

 I have been a small animal veterinarian for 20+ years with 14 years of critical care experience and perform a variety of soft tissue and orthopedic surgeries.  I have a keen interest in evolutionary and marine biology.  Years of scuba diving have provided me with a great appreciation for the marine environment.  I am not a marine mammal specialist, whatever that means, but am very knowledgeable with disease and disease processes.

The two orca necropsies were contained in NMFS’ files on the Tilikum purchase and import from Sealand, because SeaWorld updated NMFS on the deaths of Kahana (5/14/1991 at SeaWorld Texas, six months after a miscarriage) and Kenau (8/6/1991 at SeaWorld Florida and 12 months pregnant) as part of the permit application process.

 Kahana’s death is the more mystifying, as she was found with skull trauma that SeaWorld posited had resulted from a collision with the pool wall that occurred as a consequence of Kahana thrashing around in agony from an intestinal tumor. But Kenau’s death is also revealing, in that it is an example of the sorts of infections that can threaten the health of captive orcas.

Here are the necropsies, and the analysis SeaWorld provided NMFS regarding the orca deaths:

Read on to see Jon Zern’s analysis of each death.

We’ll start with Kahana:

In over 20 years of practice–and 14 of them being in critical care–my experience with acute abdomens is quite extensive including gastric dilatation volvulus, intestinal tumors causing obstructions, gastrointestinal obstructions due to foreign bodies, hemoabdomens due to ruptured splenic and/or hepatic tumors, necrotizing pancreatitis, etc. and none of these patients were in such “agonal throes” of pain that they caused their own fatality.  Although, I do have to be careful crossing the species barrier and not compare apples to oranges.

There are several discrepancies on the reports so this review is more laborious.  The Sea World veterinarian has the cerebral trauma at the right cerebrum but the University of Texas veterinarian has the cerebral trauma at the left cerebrum.  Also the Sea World veterinarian states the mycotic (fungal) infection in the lung is focal and inactive whereas the University of Texas veterinarian states that this orca has granulomatous pneumonia (active fungal pneumonia) with chronic obstructive pulmonary disease. It is interesting that Sea World attempts to diminish the serious nature of mycotic pneumonia.  How and why does this orca have Aspergillosis?  Are the artificial insemination techniques employed not sterile and/or is chronic stress immunocompromising them making them susceptible to mycotic infections?

In regards to Kahana, and her intestinal mass: the million dollar question was whether an intestinal neurofibroma could cause such intense abdominal pain that the animal could cause its own fatality?  Researching this particular mass in humans has shown that it may cause tenesmus, constipation, abdominal discomfort (cramping) and in one particular case an intussusception but even in that case with the intussusception the patient did not thrust about in “agonal throes” where she was endangering herself.

The necropsy reports that are most objective are from Dr. Lois Roth at University of Florida, Dr. John Pletcher at Department of Defense, Dr. Sam Ridgway at NOSC, and Dr. Crawley at University of Texas.  The other reports are very subjective, especially Hammond’s report which is opinionated without facts.  Very unprofessional and unscientific.

The discrepancies between left cerebral hemorrhage (University of Texas) and right cerebral hemorrhage (Sea World) are a little concerning.  If Sea World is correct and the left mandible sustained the open, comminuted fractures and the right frontal, parietal, and occipital bones of the skull sustained the fractures then this suggests two traumatic events to the skull.  The first being at the mandible when she collided with the pool wall and possibly the second when the right side of the skull collided with the pool bottom.  The cause of death obviously was extensive meningeal hemorrhage in the cerebrum, vermis of the cerebellum and third ventricle.  My experience with acute abdomens and research in intestinal neurofibromas would lead me to believe that it is highly unlikely that the intestinal mass caused this orca to behave erratically causing its own demise.  Dr. Sam Ridgway makes a good point that rupturing of the granulomatous lung lesion could have resulted in violent, involuntary activity.  This is unfortunately one of those cases where you can ask 500 doctors and receive 500 different answers.  Some of the questions that Sea World may want to try and answer is why did this orca have a mycotic pulmonary infection and do intestinal neurofibromas have a viral etiology?

And here is what Zern had to say about Kenau’s death:

I have been reviewing the necropsies extensively and have completed most of the research on the orca that died from necrotizing, hemorrhagic pneumonia (Kenau).

There are a few oversights on the history, treatment protocol,  necropsy report(s) and culture and sensitivity.

Firstly, the orca was being treated for an “infected tooth” but the history does not specify the treatment.  Also, generally disregard any necropsy report from Kissimmee Animal Diagnostics Laboratory since their level of performance has been historically substandard and inaccurate (for example, “alveoli stuffed with blood”;  not a comment that a highly regarded pathologist would make on a report). Dr. Kintner with Kissimmee did state that a gastroduodenal ulcer was discovered but Dr. Osborn states they are not ulcers. Dr. Rhyan in Ames, Iowa stated that not only did this orca die from gram-negative bacilli pneumonia but it also suffered from chronic glomerulonephropathy.

Was this orca receiving any medications that could cause renal (kidney) damage (e.g. nonsteroidal anti-inflammatory drugs-NSAIDs, aminoglycoside antibiotics, high doses of enrofloxacin-Baytril)?  Those are the most common medications that cause renal damage in veterinary patients.

Dr. Kent Osborn appeared to have performed a complete, extensive necropsy as well.  He observed gram negative bacilli at the tonsils and an unspecified lymph node.  The lymph node location was not given but if this lymph node was a submandibular lymph node and with the concomitant discovery of the bacilli within the tonsils could be highly suggestive that the infected tooth is the etiology of the pneumonia.  Surprisingly, no culture and sensitivity was collected at the “infected tooth”.

Drs. Walsh and Campbell with Sea World remark that the patient died from DIC (Disseminated intravascular coagulopathy) since fibrin splitting products were elevated, but the splenic findings were normal,  and there is no evidence of abnormal red blood cells (schistocytes, acanthocytes), coagulopathy (clotting disorder), or thrombocytopenia (low platelet count), so it is therefore unlikely DIC was the cause of death.

Drs. Campbell, Walsh, Kintner, and Wright stated the renal damage was due to “anoxia caused by cardiovascular collapse just prior to death” and this indicates acute damage.  But this is contradictory to Dr. Rhyan’s remarks regarding the kidneys which states the renal issues were chronic.  I agree with the Drs. Osborn and Rhyan that severe, acute, necrohemorrhagic pneumonia was the cause of death.   The tooth could be the etiology but without culture of that site it would be negligent to state otherwise.

A few observations that are alarming.  Dr. Ruth Francis-Floyd remarks that Pseudomonas infections are the most common type of infections in captive cetaceans and bacterial pneumonia is the most common cause of mortality in captive dolphins.  That is rather disturbing since that is a nasty organism (obviously) and hopefully that is being addressed with solid research.

Also, the report from Hammond Consultants (Dr. Douglas “Ted” Hammond) makes remarks that are inaccurate. He stated that “45% of all orcas in the wild die within the first 18 months of life”.  Where did he acquire that information?  His other remarks stating that Sea World is by far the best breeding program of any facility worldwide and the low mortality rate(s) seems more like an advertisement than a necropsy report.

Based on Zern’s analysis, I would say the cause of Kahana’s death remains a big question mark. It seems possible she could have collided with the pool wall as a result of some sort of aggressive interaction with the other orcas, a la Nakai, even if no one saw (or was willing to report) any aggression. Or perhaps something else was going on with Kahana, a la Hugo at Miami Seaquarium, who essentially killed himself by repeatedly ramming his head into the pool wall.

Kenau’s death suggests another sort of captive mortality, the risk from infections that are endemic to the captive environment, whether the infection originated from a tooth issue or some other source.

You can see how revealing these necropsies are. Which is why the marine park industry pulled a slick maneuver in 1994, and managed to change to laws governing their distribution. Naomi Rose of the Animal Welfare Institute was there as it happened, and explains:

Prior to 1994 under the MMPA (Marine Mammal Protection Act), facilities with captive marine mammals were required to send necropsy reports to APHIS (USDA’s Animal, and Plant Health Inspection Service), which kept them on file. They were thus subject to FOIA and several such necropsy reports were used to good effect in policy campaigning by NGOs. The industry didn’t like that, so they made that requirement a specific target of their MMPA amendments in 1994. After those amendments passed, necropsy reports were no longer required to be submitted to APHIS, but had to be kept on file for at least three years (I think – some number of years, anyway) at the facility, subject to submission to APHIS only upon request. And APHIS never requests.

Thus necropsy reports went from public documents to proprietary ones. All the public gets now is a one line or even one word “cause of death” from the Marine Mammal Inventory Reports.

Regarding the debate about orca captivity, I’ve long thought that the medical records and necropsy reports of SeaWorld’s orcas would tell us more about how captive orcas fare in the captive environment than any other source. And that if all is well, and orcas thrive at SeaWorld and in other marine park pools, then SeaWorld should release its medical records to show that. But they don’t. And presumably there is a very good reason that SeaWorld doesn’t share that information (and that reason is not maintaining the medical privacy of the orcas!).

So for all the reformers out there, in Congress and among the grassroots, here’s an idea that would help settle many of the questions regarding orca captivity, and most important benefit the animals themselves: require that all medical records and necropsies be submitted for federal or independent review. That would be huge.