Functional limb anatomy in a refugee species: The endangered Patagonian huemul deer (Hippocamelus bisulcus).

Early naturalists already considered huemul rare, refuged and a stocky, short-legged mountain deer, 163 years before declared endangered (1972). Anatomically, huemul do not overlap with rock-climbers previously considered analogous, as corroborated in this paper by including additional huemul cases. Assertions that population declines are caused principally via livestock infections remain unfounded. Instead, osteopathology in multiple populations across 1,000 km, affecting 57% among dead and 86% among live specimens, may relate to micronutrient deficiencies. Historically classified a mountain deer, widespread osteopathology, micronutrient deficiencies and lack of recovery qualify huemul as a refugee species. Recovery strategies thus must include repopulating historical distribution sites.

Nutrition as an etiological factor causing diseases in endangered huemul deer.

OBJECTIVES: Distinct diseases prevent endangered huemul deer (Hippocamelus bisulcus) recovery. Fundamental etiological factors include nutriments, a mayor component of habitat quality. Undernutrition affects growth, skeletal development, osteopathology, reproduction and immunocompetence: this paper amplifies data corroborating micro-nutrient deficiencies among huemul. RESULTS: In Argentina, 57% huemul cadavers exhibited osteopathology, with new cases reported here. Recently, 86% live huemul had osteopathology: cranial lesions involved antemortem tooth loss, reducing feeding efficiency and body condition, with starvation deaths. This population had tissues well deficient compared to other cervids, averaging 0.28 ppm selenium, 4.98 ppm copper, whereas for manganese 55% were deficient (2.52 ppm) and 45% adequate (42.79 ppm). Recently, lesions in one Chilean huemul were interpreted to stem from parapoxvirus. That population also has cases with cranial osteopathologies, high disease susceptibility (parapoxvirus, parasitism, foot lesions), crippled antlers, and low density, indicative of marginal habitat and primary etiological factors like undernutrition and immunosuppression. The reported atypical symptoms attributed to parapoxvirus may relate to probable diagnostic limitations, but does support presence of nutritional deficiencies. Patagonia has selenium deficient plants and livestock, including severe muscular dystrophy, and soil levels in extant huemul areas considered very deficient. Moreover, 73% of Chilean huemul were selenium deficient and 64% severely deficient with concomitant cranial osteopathology.

Elusive cranial lesions severely afflicting young endangered Patagonian huemul deer.

OBJECTIVES: Most subpopulations of endangered huemul deer (Hippocamelus bisulcus) fail to recover, frequently due to osteopathology. Equivalent pathology was detected only postmortem in an additional deer 365 km further north, stressing the need to improve clinical evaluations of live huemul. RESULTS: Captured on a farm and attended by authorities in charge of huemul, the deer was considered apt for relocation and release. Delays with attendance and lack of reversal drugs resulted in his death. The subsequent necropsy revealed severe osteopathology particularly in mandibles and maxillae. Such disease in another southern population affected 57+ % among dead adults, and 86% among live adults. The present case stems from a new subpopulation, isolated 365 km further north. Such severe pathology demands that individuals be rehabilitated, especially relevant with severely endangered species, because liberations will cause premature death and loss of reproductive lifetime. Live huemul must be examined utmost professionally especially regarding this pathophysiognomy. This incidence represents the typical situation of extant huemul, being displaced from their traditional migratory behavior to utilize fertile low-elevation habitat. This young male may have been dispersing, but reaching valleys usually leads to death due to locally intense anthropogenic activities.

Troubling disease syndrome in endangered live Patagonian huemul deer (Hippocamelus bisulcus) from the Protected Park Shoonem: unusually high prevalence of osteopathology.

OBJECTIVE: The last 1500 endangered Patagonian huemul deer (Hippocamelus bisulcus) exist in > 100 groups which are not recovering. Prevalence of osteopathology in dead huemul was 57+% (Argentina), whereas similar cases in Chile were accompanied by selenium deficiency. The first clinical cases from live wild huemul confirm widespread osteopathology which explains short life spans, low recruitment, and thus absence of population recovery. RESULTS: The first-ever radio-collaring of 3 male huemul in Argentina and 3 females, plus a fresh female carcass allowed examination of 7 huemul. Of these, 86% were diseased and clinical pathophysiognomy included lameness, affected hoof, exfoliation of 2-7 incisors, other cranial osteopathologies, and muscle atrophy. The parsimonious explanation for absent population recovery is high prevalence of osteopathology as evidenced earlier in carcasses, and now by these clinical cases. Areas currently used by huemul have reduced selenium bioavailability, very deficient soil levels, and overt selenium deficiency in local livestock and plants. These areas are known to result in primary iodine deficiency which is aggravated by selenium deficiency. The nexus to nutritional ecology of huemul likely is inaccessibility to most fertile lowlands and traditional winter ranges, elimination of migratory traditions, and concomitant elimination of source populations.

Osteopathology and selenium deficiency co-occurring in a population of endangered Patagonian huemul (Hippocamelus bisulcus).

BACKGROUND: About 1,000 endangered Patagonian huemul deer (Hippocamelus bisulcus) remain in Chile and 350-500 in Argentina. Most groups (>100) are not recovering, and prevalence of osteopathology in Argentina was at least 57%. Here I describe relevant cases of osteopathology from a Chilean population which, however, recently also provided data on trace mineral status, supporting the initial hypothesis that nutrition may be a primary etiologic factor. Additionally, recent data on bone chemical composition of Argentine cases and soil analyses are discussed. RESULTS: Fluoride levels in Argentine cases with osteopathology were low and fluorosis was discarded as an etiological factor. Selenium deficiency occurred in 73% of huemul from the Chilean population which exhibited several cases with osteopathology. The pathophysiognomy included extensive erosion; tooth loss; porosification; perforations of palate, maxillar and mandibular bone with frequent exposure of tooth roots; and fractured mandibula. Areas currently used by remaining huemul have mainly acidic volcanic soils, which reduces selenium bioavailability: mean soil selenium levels from areas typically used by extant huemul were very deficient (0.19 ppm), corroborating documented overt selenium deficiency in local livestock and plants. The area of extant huemul is known to result in primary iodine deficiency in livestock which is aggravated by selenium deficiency. CONCLUSIONS: Currently the most parsimonious explanation for frequent osteopathology and lack of numerical recovery are the combined effects of selenium and iodine deficiencies based on: osteopathology in a population of selenium deficient huemul; selenium deficient livestock, plants and soils; acidic soils; and regional primary iodine deficiency. The nexus between mineral nutrition and population dynamics of huemul may be due to constraints on their movements to fertile lowlands, including the elimination of historic migratory traditions, and concomitant elimination of source populations.

Severe dental fluorosis in juvenile deer linked to a recent volcanic eruption in Patagonia.

The Puyehue-Cordon Caulle volcanic eruption deposited large amounts of tephra (ashes) on about 36 million ha of Argentina in June of 2011. Tephra was considered chemically innoxious based on water leachates, surface water fluoride levels were determined to be safe, and livestock losses were attributable to inanition and excessive tooth wear. To evaluate effects on wild ungulates, we sampled wild red deer (Cervus elaphus) at 100 km from the volcano in September-November 2012. We show that tephra caused severe dental fluorosis, with bone fluoride levels up to 5,175 ppm. Among subadults, tephra caused pathologic development of newly emerging teeth typical of fluorosis, including enamel hypoplasia, breakages, pitting, mottling, and extremely rapid ablation of entire crowns down to underlying pulp cavities. The loss of teeth functionality affected physical condition, and none of the subadults was able to conceive. Susceptibility to fluorosis among these herbivores likely resides in ruminant food processing: 1) mastication and tephra size reduction, 2) thorough and repeated mixing with alkaline saliva, 3) water-soluble extraction in the rumen, and 4) extraction in the acidic abomasum. Although initial analyses of water and tephra were interpreted not to present a concern, ruminants as a major component of this ecosystem are shown to be highly susceptible to fluorosis, with average bone level increasing over 38-fold during the first 15.5 mo of exposure to tephra. This is the first report of fluorosis in wild ungulates from a volcanic eruption. The described impact will reverberate through several aspects of the ecology of the deer, including effects on population dynamics, morbidity, predation susceptibility, and other components of the ecosystem such as scavenger and plant communities. We anticipate further impact on livestock production systems, yet until now, existence of fluorosis had not been recognized.

Age-independent osteopathology in skeletons of a South American cervid, the Patagonian huemul (Hippocamelus bisulcus).

The huemul (Hippocamelus bisulcus), an endemic Patagonian deer, has been endangered for decades. Although conservation in Argentina has been directed at the 350-600 remaining huemul, the population has not recovered. In initial studies on the potential effects of diseases on huemul population dynamics, skeletal remains collected between 1993 and 2007 in the Andes (41-45 degrees S, 71.5-72 degrees W) were examined macroscopically for osteopathologic changes. Bones from six huemul were free of lesions, findings were inconclusive in 13 huemul with less than three bones, and osteopathologic processes were detected in 13 adults. Considering the limited remains/case, the prevalence of osteopathy (52%) among adults probably is conservative; 63% showed mandibular, 100% maxillary, and 78% appendicular lesions. Although predation represented the actual cause of death, the observed skeletal lesions would affect predator avoidance, possibly explaining the low average adult age (3.1 yr) and lack of population recovery. Compared with other studies in ungulates, huemul were affected at a younger age, and they had more severe pathologic changes. Due to the chronic nature of disease, low huemul population density, physiognomy, and spatiotemporal pattern of lesions, we discard senescence; gender; fulminating infections; congenital anomalies; metabolic, endocrine, genetic, or neurologic disorders; parasitism or marasmus; and fluorosis as primary etiologic factors. We hypothesize that generalized secondary chronic alveolar osteomyelitis and osteoarthritis in huemul is related to the nutritional ecology of these animals. Selenium deficiency, which impairs bone metabolism and causes periodontitis in ruminants, occurs in the region and it is more prevalent at high altitudes. Traditional winter grounds at low elevations, sometimes far from high mountains, have been converted to livestock production, which has eliminated migratory behavior and keeps huemul in remote high-elevation refuges. Although this descriptive study contributes to huemul conservation, additional approaches are needed to investigate the etiology of this osteopathy and to close other gaps in knowledge on biology and ecology of huemul.

Potential existence of a sylvatic cycle of Taenia ovis krabbei in Patagonia, Argentina.

Red deer (Cervus elaphus) were introduced in southern Latin America about a century ago and characteristics of the invasion raise concerns over their epidemiological role for various diseases. We report on the possible occurrence of Taenia ovis krabbei established in a sylvatic cycle in Patagonia. Hook characters, size, appearance, and location of a cysticercus from a wild red deer are consistent with Taenia ovis ovis or T. o. krabbei. Although it is not possible to differentiate between T. o. ovis and T. o. krabbei on morphological grounds with certainty, several biological characteristics indicate the cysticercus may belong to T. o. krabbei. Red deer have been reported to be refractory to T. o. ovis infection whereas other potential intermediate hosts like cattle, goats, pigs and sheep have been shown to be refractory to T. o. krabbei. Other native ungulates sympatric with red deer in Patagonia include Lama guanicoe and the endangered huemul deer (Hippocamelus bisulcus). Possible or known definitive hosts include native felids like Puma concolor, Felis colocolo, F. guigna and canids like Dusicyon griseus, D. culpaeus, and domestic dogs.