Evaluation of ivermectin for treatment of hair loss syndrome in black-tailed deer

Since 1997, numerous Columbian black-tailed deer (Odocoileus hemionus columbianus) in western Washington (USA) have developed a hair loss syndrome that often preceded emaciation, debilitation, pneumonia, and death. To study this syndrome, eight affected free-ranging Columbian black-tailed deer fawns were captured from western Washington in February 1999 to determine the effect of ivermectin treatment. Fecal examinations indicated that the internal parasites were Dictyocaulus viviparus, Parelaphostrongylus sp., Trichuris sp., Moniezia sp., Eimeria spp., and gastrointestinal strongyles. Biting lice (Tricholipeurus parallelus) were observed on all deer, with up to 5 lice/cm(2) on the index areas counted. Three deer were treated with ivermectin subcutaneously at doses between 0.2 and 1.3 mg/kg of body weight monthly for four consecutive months, and five control deer received no anthelmintic treatment. Complete blood counts, parasite evaluations, weight gains, and hair loss evaluations were used to assess effectiveness of treatment. Two untreated deer died during the experiment compared with no deaths among the three treated deer. Treated deer gained significantly more weight (P<0.05) than the untreated deer (22.4 vs. 12.6 kg, respectively) that survived the experiment, had significantly fewer parasite eggs and larvae (P<0.05) in feces and significantly fewer nematodes (P<0.05) at necropsy, and regrew their hair at a faster rate than untreated deer. Lice and all nematode eggs and larval stages in feces were eliminated or greatly reduced following treatment. On the basis of these data, excessive louse populations, gastrointestinal nematodes, and the lung-worms Parelaphostrongylus sp. and D. viviparus, might be important predisposing factors for this hair loss condition and death of affected animals.     

Species-wide phylogeography of North American mule deer (Odocoileus hemionus): cryptic glacial refugia and postglacial recolonization

Quaternary climatic oscillations greatly influenced the present-day population genetic structure of animals and plants. For species with high dispersal and reproductive potential, phylogeographic patterns resulting from historical processes can be cryptic, overshadowed by contemporary processes. Here we report a study of the phylogeography of Odocoileus hemionus , a large, vagile ungulate common throughout western North America. We examined sequence variation of mitochondrial DNA (control region and cytochrome b ) within and among 70 natural populations across the entire range of the species. Among the 1766 individual animals surveyed, we recovered 496 haplotypes. Although fine-scale phylogenetic structure was weakly resolved using phylogenetic methods, network analysis clearly revealed the presence of 12 distinct haplogroups. The spatial distribution of haplogroups showed a strong genetic discontinuity between the two morphological types of O. hemionus , mule deer and black-tailed deer, east and west of the Cascade Mountains in the Pacific Northwest. Within the mule deer lineage, we identified several haplogroups that expanded before or during the Last Glacial Maximum, suggesting that mule deer persisted in multiple refugia south of the ice sheets. Patterns of genetic diversity within the black-tailed deer lineage suggest a single refugium along the Pacific Northwest coast, and refute the hypothesis that black-tailed deer persisted in one or more northern refugia. Our data suggest that black-tailed deer recolonized areas in accordance with the pattern of glacial retreat, with initial recolonization northward along a coastal route and secondary recolonization inland.     

Hair-loss epizootic in moose (Alces alces) associated with massive deer ked (Lipoptena cervi) infestation

Deer keds (Lipoptena cervi) are blood-sucking flies in the family Hippoboscidae; moose (Alces alces) are their main host in Scandinavia. There are no detailed reports of the negative impacts of deer keds on moose. In 2006 and 2007, hunters in southeastern Norway and midwestern Sweden found several moose cadavers with severe alopecia; numerous moose had extensive hair loss. Between February 2006 and June 2007, materials from 23 moose were submitted for laboratory examination and large numbers of deer keds were found in the coat of most animals. The body condition of the moose varied but was poor in animals with severe alopecia. The findings of enormous numbers of deer keds in the coat of the majority of the affected animals and a consistent histologic image (acute to chronic, multifocal to coalescing, eosinophilic to lymphocytic dermatitis), concurrent with the absence of any other lesions, trace element deficiencies, or dermal infections which are known to cause alopecia, suggest that the hair-loss epizootic was linked to massive infestations with deer keds. The emergence of this hair-loss syndrome implies that the dynamics between parasite and host have been disrupted by a currently unknown environmental or ecological factor. A high moose density, combined with extraordinarily mild weather June 2006-June 2007 and a particularly long period with the absence of night-frost in autumn of 2006, may have been ideal for deer ked development, survival, and optimal host acquisition.     

Experimentally induced Fasciola hepatica infections in black-tailed deer.

The susceptibility of black-tailed deer (Odocoileus hemionus columbianus) to the common liver fluke (F. hepatica) was studied. Two deer and one sheep comprised each of three experimental groups. Animals in each group were inoculated individually with 250, 500, or 1000 F. hepatica metacercariae. One deer and one sheep given 1000 metacercariae died with lesions consistent with black disease 7 weeks after inoculation. At necropsy 6 or 15 weeks postinoculation, the mean percentage recovery of the inoculum was 38.9% from the deer and 51.9% from the sheep. Fluke eggs recovered from the deer were viable and metacercariae cultured from the eggs were fully infective for sheep. Pathologic changes associated with F. hepatica infection were more severe in the infected deer; consequently, the deer were less resistant to the lethal effects of the parasite than sheep. Considering the experimental results and the fact that naturally acquired common liver fluke infection has been reported infrequently from black-tailed deer, it was concluded that black-tailed deer do not constitute a significant reservoir for F. hepatica in domestic livestock.     

Xenobiotic biotransformation in livers and lungs of adult black-tailed deer: comparison with domestic goat and sheep

1. The capacity of liver and lung tissue of black-tailed dear (Odocoileus hemionus columbianus) to biotransform xenobiotics was compared in vitro to the domestic sheep and goat. Donor animals were all females of varying ages. Tissues from the black-tailed deer were collected in the wild. A variety of biotransformation enzymes were measured in both microsomal and cytosolic fractions. 2. Deer liver was lower in total cytochrome P450 concentration, but mono-oxygenase activities were greater compared to sheep and goat. The opposite was true for the lung. 3. Epoxide hydrolase activities were significantly different in deer vs sheep and goat. 4. In general, both hepatic and pulmonary activities were more similar between sheep and goat than either species compared to the deer, however, the magnitude of the hepatic differences did not exceed 5-fold. 5. Based on these limited results, there is no reason to discredit the sheep or goat as a toxicity testing model for deer.     

Immune Phenotype and Body Condition in Roe Deer: Individuals with High Body Condition Have Different,Not Stronger Immunity

An efficient immunity is necessary for host survival, but entails energetic costs. When energy is limited, immunocompetence and body condition should co-vary positively among individuals and, depending on body condition, individuals should allocate more either in innate immunity or in adaptive response. We tested whether immune phenotype depends on body condition in large mammals, using data from two contrasted populations of roe deer Capreolus capreolus in France. Roe deer living at Chizé, a forest with poor habitat quality, were expected to show lower values for body condition and immune parameters than roe deer at Trois Fontaines, a forest with high habitat quality. From 285 blood samples collected between December 2009 and March 2011, we measured seven metabolic parameters and ten immunological parameters. A Principal Component Analysis showed that all indicators of body condition co-varied positively and were lowest at Chizé. Several immunological indicators correlated to body condition and differed between Trois Fontaines and Chizé. However, high body condition was not associated to a high average level of immunocompetence, but instead to high levels of indicators of acute inflammatory innate response, while low body condition was associated to high levels of monocytes and lymphocytes, possibly reflecting adaptive immunity. Limited data suggest that the difference between populations was not related to the presence of specific parasite species, however parasite exposure and stress have to be investigated to gain a more complete understanding of the determinants of immunity.     

Resource partitioning between sympatric columbian white-tailed and black-tailed deer in western Oregon

We studied resource partitioning between sympatric populations of Columbian white-tailed (CWTD; Odocoileus virginianus leucurus) and black-tailed (BWTD) deer (O. odocoileus hemionus columbianus) in western Oregon to understand potential mechanisms of coexistence. We used horseback transects to describe spatial distributions, population overlap, and habitat use for both species, and we studied diets with microhistological analysis of fecal samples. Distribution patterns indicated that white-tailed and black-tailed deer maintained spatial separation during most seasons with spatial overlap ranging from 5%–40% seasonally. Coefficients of species association were negative, suggesting a pattern of mutual avoidance. White-tailed deer were more concentrated in the southern portions of the study area, which was characterized by lower elevations, more gradual slopes, and close proximity to streams. Black-tailed deer were more wide ranging and tended to occur in the northern portions of the study area, which had higher elevations and greater topographical variation. Habitat use of different vegetative assemblages was similar between white-tailed and black-tailed deer with overlap ranging from 89%–96% seasonally. White-tailed deer used nearly all habitats available on the study area except those associated with conifers. White-tailed deer used oak-hardwood savanna shrub, open grassland, oak-hardwood savanna, and riparian habitats the most. Black-tailed deer exhibited high use for open grassland and oak-hardwood savanna shrub habitats and lower use of all others. The 2 subspecies also exhibited strong seasonal similarities in diets with overlap ranging from 89% to 95%. White-tailed deer diets were dominated by forbs, shrubs, grasses, and other food sources (e.g., nuts and lichens). Columbian black-tailed deer diets were dominated mostly by forbs and other food sources. Seasonal diet diversity followed similar patterns for both species with the most diverse diets occurring in fall and the least diverse diets in spring. High overlap in habitat use and diets resulted in high trophic overlap (81–85%) between white-tailed and black-tailed deer; however, the low spatial overlap reduced the potential for exploitative competition but may have been indicative of inference competition between the species. Diverse habitat and forage opportunities were available on the study area due to heterogeneous landscape characteristics, which allowed ecological separation between white-tailed and black-tailed deer despite similarities in diets and habitat use. We make several recommendations for management of CWTD, a previously threatened species, based on the results of our study. © 2011 The Wildlife Society.     

Fluorosis in black-tailed deer.

Marked dental disfigurement and abnormal tooth wear patterns were observed in black-tailed deer (Odocoileus hemionus columbianus) taken from an area near an industrial fluoride source in northwestern Washington. Fluoride levels in the bones of these deer were from 10 to 35 times higher than levels in the bones of normal animals. These levels are similar to those associated with fluorosis of cattle.     

日本梅花鹿与大丰麇鹿发情期反刍行为的差异

家养有蹄类动物的反刍行为已有大量研究,而受限于野外条件,野生有蹄类动物反刍行为的研究有限。以往研究认为,体型可能是影响动物反刍行为的重要因素。本研究以日本奈良公园日本梅花鹿Cervus nippon nippon和中国江苏大丰麋鹿Elaphurus davidianus为研究对象,观察记录并比较分析了发情期的日本梅花鹿与发情期的麋鹿在卧息时反刍行为的种内及种间差异。按照年龄性别差异,分5种类型(成年雄性、成年雌性、亚成雄性、亚成雌性和幼鹿)研究两物种食团咀嚼时间、咀嚼频率和咀嚼速率的差异。结果表明,1)日本梅花鹿的咀嚼速率和食团咀嚼时间受性别-年龄的显著影响:咀嚼速率为幼体>亚成雌性>亚成雄性>成年雌性>成年雄性,而食团咀嚼时间为成年雄性>亚成雄性>成年雌性>亚成雌性>幼体;2)性别-年龄对麋鹿咀嚼频率有显著的影响,成年雄性<成年雌性<亚成雄性<亚成雌性<幼体;3)两物种在咀嚼频率、食团咀嚼时间和咀嚼速率上的差异均有统计学意义,体型更大的麋鹿咀嚼速率更慢,食团咀嚼时间更长。与体型相关的性别及年龄显著影响了日本梅花鹿和麋鹿的反刍行为。     

Supplementary winter feeding of wild red deer Cervus elaphus in Europe and North America: justifications, feeding practice and effectiveness

1. Supplementary winter feeding of game animals, and particularly deer, is a common practice throughout northern (continental) Europe and parts of North America. Feeding is normally associated with maintaining high densities of animals for hunting, in terms of: (i) maintaining or increasing body weights and condition overwinter; (ii) improving reproductive performance and fertility; (iii) increasing overwinter survival; and (iv) reducing levels of damage caused to agriculture and forestry or the natural heritage. We consider the balance of evidence on the effectiveness of winter feeding of red deer Cervus elaphus in achieving these objectives. Where that evidence is equivocal, we attempt to reconcile apparent contradictions to evaluate the circumstances under which winter feeding may or may not be effective. 2. In general, feeding of red deer on open range appears to have relatively little effect on body weights or fecundity. Effects on increasing antler size and quality are variable and seem to depend on the degree to which animals may be mineral limited on native range. Effects on survival are similarly ambiguous. It is apparent, however, that to be effective in reducing mortality, any supplementation is required early in the season and not simply when heavy mortalities are already being experienced. If provision of supplementary foods is delayed until animals are perceived already to be in poor condition, such feeding may have little effect. 3. One of the primary goals of winter feeding in both Europe and the USA has become the prevention of environmental damage, particularly damage to commercial and native forests, while maintaining deer populations at densities suitable for hunting. Again, empirical evidence for effectiveness in this regard is inconclusive, with some studies showing a decrease in damage caused, some showing no effect and others showing a significant increase in local impact. 4. There are equally a number of problems associated with the provision of supplementary feeds overwinter. Those animals which come to the feeding stations may develop a reliance on the food supplement provided, reducing intake of natural forages to near zero; where feed provided is less than 100% of daily requirement, such animals may regularly lose, rather than gain condition. Feed provision is also extremely uneven at such feeding stations; dominant stags displace younger stags and hinds from the feed provided until they have themselves finished feeding. Concentrations of high densities of animals around small feed‐areas may also increase the risk of infection and lead to development of high parasite burdens. 5. In an attempt to assess the current status and distribution of supplementary winter feeding in Scotland, a questionnaire was circulated to a number of individual across the country. Results of this survey are summarized and conclusions presented on the likely effectiveness of current feeding practices in achieving their aims.     

Epizootiology of spirorchiid infection in green turtles (Chelonia mydas) in Hawaii

We describe the epizootiology of spirorchiid trematode infections in Hawaiian green turtles (Chelonia mydas) by quantifying tissue egg burdens in turtles submitted for necropsy and by assessing antibody response to crude adult worm and egg antigens among a variety of age groups. Hapalotrema sp. and Laeredius sp. predominated in turtles infected with spirorchiids. Tissue egg burdens decreased with increasing size and increased with deteriorating body condition of turtles. No relationship was found between tissue egg burdens and sex or fibropapillomatosis status. Tissue egg burdens increased in turtles from southeast to northwest in the main Hawaiian Islands (Hawaii to Kauai). Hatchling and captive-reared turtles had significantly lower levels of antibodies against crude worm and egg antigens. Based on tissue egg burdens and antibody status, we hypothesize that immature turtles become infected with spirorchiids shortly after recruiting into coastal foraging pastures from the pelagic environment, that infection levels decrease with age, and that spirorchiids detrimentally affect the body condition of sea turtles independent of tumor burden. The low intensity of infection in turtles with the endemic trematode Carettacola hawaiiensis suggests either that turtles are less susceptible to infection with this parasite or that the parasite is outcompeted by species of Hapalotrema and Laeredius. Given that the 2 latter species are found in the Pacific and other oceans, they are not likely endemic and were probably introduced into Hawaii through an undetermined route.     

Demodicosis in a mule deer (Odocoileus hemionus hemionus) from Saskatchewan, Canada

Infestation of deer with Demodex spp. mites has been described in white-tailed deer (Odocoileus virginianus) and in Columbian black-tailed deer (Odocoileus hemionus columbianus) in North America, as well as in four species of deer in Europe. We describe Demodex sp. infestation in an adult female mule deer (Odocoileus hemionus hemionus) with skin lesions found dead near Saskatoon, Saskatchewan, Canada. This is believed to be the first report of demodicosis in mule deer.     

Abomasal nematodes of the red deer Cervus elaphus in north-eastern Italy

The composition of the abomasal helminth fauna and parasite diversity were studied in 298 red deer collected during 1997-2000 from three different sectors (Bolzano, Trento and Sondrio provinces) of the Stelvio National Park, one of the main protected areas of north-eastern Italy. The association between parasite burdens and geographical areas of the hosts was assessed using the negative binomial regression. A variety of abomasal helminths, both host specific and generalist, was found in all sectors. The most commonly observed parasites were the Spiculopteragia spiculoptera morph spiculoptera and Ostertagia leptospicularis morph leptospicularis, with prevalences of 79.5% and 40.9%, respectively. The minor morphs S. spiculoptera morph mathevossiani (prevalence 31.9%) and O. leptospicularis morph kolchida (18.8%) occurred at lower prevalences. Teladorsagia circumcincta morph circumcincta, Marshallagia marshalli morph marshalli and Haemonchus contortus were rarer, at prevalences of 1, 1.3 and 1.3%, respectively. Deviance analysis of the negative binomial regression model shows that the geographical area is significantly related to parasite burdens (P = 0.001). Prevalences of hosts with parasites were greater in the Sondrio (odds ratio = 1.31; 95% confidence interval: 0.16-10.85) and smaller in the Trento (odds ratio = 0.62; 95% confidence interval: 0.20-1.96) sectors with respect to Bolzano, but these differences were not statistically significant. Possible cross-infections by more generalist parasites between wild and domestic animals were also suggested, as deer and domestic ruminants (Bovinae, Caprinae and Ovinae) used the same feeding areas of the park sectors.     

Sex-Age Related Rumination Behavior of Père David’s Deer under Constraints of Feeding Habitat and Rainfall

Extensive studies have been conducted on the rumination behavior of domestic herbivores. However, studies on wild animals are limited, particularly wild animals with specific ruminating parameters. In this study, Père David’s deer, a previously extirpated species, was observed to analyze the effects of sex-age, feeding habitat, and rainfall on rumination behavior in the Dafeng Nature Reserve, China. Rumination behavior was investigated based on four parameters: proportion of bedding time spent chewing, bolus processing time (s/bolus), chewing frequency (chews/bolus), and chewing rate (chews/s). Results showed that all three factors affect rumination behavior. The extent of their effects varied based on the four rumination parameters. Chewing rate and frequency decreased based on sex–age levels, i.e., from fawns to juvenile female, juvenile male, adult female, stag, and harem holder. Therefore, body size played a major role in shaping rumination behavior. Deer found in grasslands could chew faster compared with deer found in woodlands. This result might be caused by the effects of dietary composition and sunlight intensity. A deer spends a longer time ruminating while bedding during rainy days compared with rainless days to maximize energy and nutrition intake and compensate for the loss of feeding time during rainy days. Therefore, rumination behavior is plastic and is shaped by intrinsic and extrinsic factors.     

A Spatially Explicit Model to Predict Radiocesium Body Burdens of White-Tailed Deer on the U.S. Department of Energy's Savannah River Site

We developed a spatially explicit exposure model to interpolate and predict radiocesium (¹³⁷Cs) body burdens found in white-tailed deer (Odocoileus virginianus) on the U.S. Department of Energy's (USDOE) Savannah River Site (SRS) to gain insight into and differentiate between the main contributing sources of this radionuclide for use in harvest management strategies that focus on minimizing human risk. Hunting has been allowed from permanent stands as a mechanism to manage the deer herd since 1965. All animals are monitored in the field for gross beta and gamma activity levels, providing a spatially explicit dataset. The models described here use the relative locations of the hunt-stands to predict ¹³⁷Cs exposure distributions. We used kriging to create an interpolation surface using average white-tailed deer body burdens. Cross-validations of the kriged surfaces differentiated between sources of ¹³⁷Cs and where deer reside on the SRS. The kriged surfaces, coupled with additional regression analyses, provide a comprehensive assessment of deer's ¹³⁷Cs body burdens with predictive capability that quantifies the scale at which such investigations can be conducted. Although the models are local in scale, the methods presented here can be used as a template for other large areas that are being monitored for radioactive fallout.     

Winter fawn survival in black-tailed deer populations affected by hair loss syndrome

Overwinter fawn mortality associated with hair loss syndrome (HLS) is anecdotally thought to be important in declines of Columbian black-tailed deer (Odocoileus hemionus columbianus) populations in Washington and Oregon (USA). We determined prevalence of HLS in black-tailed deer, September and April fawn:doe ratios, and minimum overwinter survival rates of fawns for selected game management units (GMUs) in western Washington from 1999 to 2001. Prevalence of HLS ranged from 6% to 74% in fawns and 4% to 33% in does. Minimum fawn survival ranged from 0.56 to 0.83 and was unrelated to prevalence of HLS in either does (r=0.005, P=0.991) or fawns (r=-0.215, P=0.608). The prevalence of HLS in either does or fawns was also unrelated to either fall fawn:doe ratios (HLS does: r=-0.132, P=0.779; HLS fawns: r=0.130, P=0.760) or spring fawn:doe ratios (HLS does: r=-0.173, P=0.711; HLS fawns: r=-0.020, P=0.963). However, the prevalence of HLS in does and fawns was strongly related (r=0.942, P=0.002), and GMUs with high prevalence of HLS had lower deer population densities (fawns: r=-0.752, P=0.031; does: r=-0.813, P=0.026). Increased overwinter mortality of fawns because of HLS was not supported by our data. Decreased production of fawns, increased summer mortality of fawns, or both were seen in six of eight study GMU-year combinations. Observed rates of productivity and minimum fawn survival were inadequate to maintain population size in five of eight study GMU-year combinations, assuming an annual doe survival rate of 0.75. The influence of deer condition and population health on adult survival, fawn production, preweaning fawn survival, parasitism, and prevalence of HLS in both fawns and adults need to be clarified to identify what factors are limiting black-tailed deer productivity.     

Spirochetes in mammals and ticks (Acari: Ixodidae) from a focus of Lyme borreliosis in California

In northern California, antibodies to Borrelia burgdorferi were detected in 58 of 73 (79%), and spirochetemias in one of 26 (4%) black-tailed jackrabbits (Lepus californicus californicus), by indirect and direct immunofluorescence, respectively. Five species of ticks (Dermacentor occidentalis, D. parumapertus, Ixodes neotomae, I. pacificus, and Haemaphysalis leporispalustris) were collected from rabbits. Two of these species of ticks were found to contain spirochetes; two of 10 (20%) I. neotomae and two of 174 (1%) H. leporispalustris. A strain of B. burgdorferi was recovered from I. neotomae. One infected H. leporispalustris female passed spirochetes via eggs to about 67% of her progeny. The widespread distribution of the black-tailed jackrabbit, its infestation by at least four ticks (D. occidentalis, D. parumapertus, I. neotomae, and I. pacificus) known to be infected naturally with B. burgdorferi, and the high prevalence of spirochetal antibody in this lagomorph suggest that it might be useful as a sentinel for surveillance of Lyme borreliosis. Spirochetes were detected in 15% of 40 Columbian black-tailed deer (Odocoileus hemionus columbianus) by direct immunofluorescence bound with a Borrelia-specific monoclonal antibody (H9724), but not with a monoclonal antibody (H5332) specific for B. burgdorferi. The geographical overlap of different borreliae in ticks that bite wildlife such as deer may confound spirochetal serosurveys, and underscores the need for more specific serologic tests than those currently available.     

Parelaphostrongylus odocoilei: Life cycle in experimentally infected cervids including the mule deer, Odocoileus h. hemionus

The life cycle of a metastrongyloid nematode, Parelaphostrongylus odocoilei, was successfully completed in three members of the Cervidae: mule deer (Odocoileus h. hemionus), black-tailed deer (O. h. columbianus), and moose (Alces alces andersoni). The terrestrial gastropod, Triodopsis multilineata, was the experimental intermediate host. White-tailed deer (O. virginianus dacotensis) were refractory to infection. The prepatent period of P. odocoilei was significantly shorter in mule deer (X = 53 days) than in the black-tailed deer or moose. There was an inverse relationship between the size of the infective inoculum and the duration of the prepatent period of P. odocoilei in mule deer, but not in black-tailed deer. The duration and intensity of larval production of P. odocoilei were higher in mule deer than in the other hosts. Peak larval production in the feces (approximately 14,000 larvae/g) of mule deer was in excess of previous reports for elaphostrongyline nematodes, regardless of the size of the infective inoculum. Daily larval production, estimated at 3 to 4 × 10⁶ larvae/day, was six times higher than estimates for other elaphostrongylines. The duration of patency was not clearly established, but three mule deer and one black-tailed deer passed larvae for 12, 18, 24, and 18 months, respectively. On the basis of the reduced prepatent period and increased length and intensity of larval production, O. h. hemionus is considered the primary host of P. odocoilei.