The next frontier for recovering endangered huemul (Hippocamelus bisulcus): How to avoid recurrent misdiagnoses of health status and risks

Abstract

Context: The currently remaining 350-500 huemuls in Argentina are not recovering. We evaluated live huemuls, along with animals that died soon after confinement, or those that had died recently. Although information on the health status is highly valuable, repeated misdiagnoses of the health status indicate a need for other strategies. Aims:. Discrepancies between clinical and postmortem diagnoses are critical for improving subsequent management decisions. Methods: Initial clinical interpretations and risk assessments were reinterpreted on the basis of necropsies and other data. Results: Two debilitated huemul individuals examined by veterinarians died soon afterwards, supposedly one being intoxicated and one being without lesions. Necropsies showed osteopathology and fluorosis (fluorine concentrations of 2209 and 2979 mg/kg). Another male was tied up, with authorities and veterinarians arriving the next day. After being sedated, and judged healthy, the animal was translocated. Because there was no reversal, this animal died 22 h post-capture. Exhumation showed severe osteopathology. Elsewhere, huemuls were considered adequate in selenium because values below the detection limit were excluded. However, when all values were included, 75% of the animals were selenium-deficient; this population had numerous cases of osteopathology. Recently, specialists went to Torres del Paine Park suspecting caseous lymphadenitis, reporting of which has been obligatory since 1937. However, many cases documented in 1999-2007 have not elicited responses since that time by health professionals. Selenium deficiency negatively affects antibody responses against caseous lymphadenitis. One province had denied huemul capture (2012 and 2013) on recommendation of scientific advisors. Because of the right for transparency, it was found out in 2016 that authorities had requested advice from only one veterinarian who assessed that darting was too risky. Another 2016 project proposed to dart the first huemul in Argentina. Two weeks earlier, that same team was called to rescue a tied-up huemul; the team opted not to involve a laboratory with drugs and radios that was only 1 h away. This huemul died and was left in the woods. Finally, the first huemul enclosure in Argentina was proposed (1995), but the permission was denied. Again, in 2000, the first huemul centre with private funding secured for 30 years was proposed. However, the Regional Delegation for Patagonian National Parks prevented aerial surveys, and advised not to provide a permit for the centre. Conclusions: Future assessments should consider osteopathology. Risk assessments should be transparent and based on assessment by multiple qualified professionals. Implications: Clinical misdiagnoses may reduce life expectancy, in contrast to taking individuals to enclosures, which would also allow valuable reintroductions. Not permitting captures, censusses and enclosures has resulted in unwarranted delays in conservation progress.