Parasites, diseases, and health status of sympatric populations of sika deer and white-tailed deer in Maryland and Virginia

In July 1981, investigations on parasites, diseases, and herd health status were conducted on sympatric populations of sika deer (Cervus nippon) and white-tailed deer (Odocoileus virginianus) from Blackwater National Wildlife Refuge (Maryland) and Chincoteague National Wildlife Refuge (Virginia) on the Delmarva Peninsula. Five adult deer of each species were collected from each location and subjected to thorough necropsy examinations and laboratory tests. White-tailed deer at both locations harbored protozoan, helminth, and arthropod parasites typically associated with this species throughout the southeastern United States. In contrast, sika deer at both locations harbored only light burdens of ticks, chiggers, and sarcocysts. Serologic tests for antibodies to seven infectious disease agents revealed evidence of exposure to bovine virus diarrhea (BVD) virus, infectious bovine rhinotracheitis virus, and parainfluenza3 virus in white-tailed deer, but only BVD virus in sika deer. At both locations the general health status of sika deer was superior to that of white-tailed deer.     

Survey of haircoat fungal flora for the presence of dermatophytes in a population of white-tailed deer (Odocoileus virginianus) in Virginia

Before releasing rehabilitated wildlife, patients should be cured of all infectious agents that pose a risk to free-roaming wildlife or humans after release. Dermatophyte fungi, commonly known as "ringworm," have zoonotic potential and may be carried as normal flora on the haircoats of certain species. Outbreaks of ringworm are anecdotally reported to occur in white-tailed deer (Odocoileus virginianus) fawns, but no prevalence surveys have been conducted on the haircoat flora of free-roaming individuals. In November 2008, we tested 60 legally hunted white-tailed deer for dermatophyte flora by using a modified MacKenzie technique. Results indicate it is unlikely that wild, mature white-tailed deer in Virginia, USA, carry dermato-phyte fungi as normal haircoat flora. Therefore, wildlife rehabilitators and hunters are at low risk for dermatophyte infection by direct contact with this species. In addition, the RapidVet-D 3 Day Test for Veterinary Dermatophytosis was determined to have poor specificity for presence of dermatophyte fungi on asymptomatic white-tailed deer in Virginia.     

Parasitism among white-tailed deer and domestic sheep on common range

Parasitism was studied in white-tailed deer (Odocoileus virginianus) and domestic sheep (Ovis aries) which shared a common range in eastern West Virginia. Of 30 species of internal parasites, 11 were found in deer and 22 in sheep. Five parasites, Sarcocystis sp., Cysticercus tenuicollis, Oesophagostomum venulosum, Cooperia punctata, and Gongylonema pulchrum, occurred in both deer and sheep. An index of similarity of 17.2 suggests that the parasite faunas of these hosts are distinct, and that it is unlikely that white-tailed deer are reservoirs of common parasites of domestic sheep in the southern Appalachian region.     

An update on the distribution of Parelaphostrongylus tenuis in the southeastern United States

An update is presented on the distribution of the meningeal worm (Parelaphostrongylus tenuis) of white-tailed deer (Odocoileus virginianus) in the southeastern United States. The parasite is widely distributed and common in all or much of Arkansas, Kentucky, Louisiana, Maryland, North Carolina, Tennessee, Virginia and West Virginia. It is also common in the northern half of Alabama and Georgia. In contrast, it is rare or absent along the Atlantic and Gulf coastal plains of Alabama, Georgia, Mississippi and South Carolina. It has been collected from a single deer in Florida.     

Acute sarcocystosis in a captive white-tailed deer in Virginia

A 19-mo-old female captive white-tailed deer in a public wild animal park in Richmond (Virginia, USA) was necropsied and evaluated histologically following spontaneous death after a 1 wk period of lethargy in a captive herd of 22 deer. An acute necrotizing pneumonia was associated with intraendothelial protozoal schizonts that were identified immunohistochemically as Sarcocystis spp. This is the first confirmed report of acute sarcocystosis in a wild ruminant.     

Apteragia pursglovei sp. n. (Trichostrongyloidea: trichostrongylidae) from the white-tailed deer, Odocoileus virginianus.

Two species of Apteragia were found in white-tailed deer (Odocoileus virginianus) from 152 counties in 13 southeastern states. Specimens previously reported as Skrjabinagia odocoilei were reidentified as belonging to 2 similar species of the genus Apteragia, A. odocoilei, and A. pursglovei sp. n. Apteragia pursglovei sp. n. is differentiated primarily by the length, conformation, and degree of sclerotization of the spicules. Of the 824 deer, A. odocoilei occurred in 76.5%, A. pursglovei in 13.8%, both species in 5.0%, and neither in 4.7%. Reassessment of distribution data revealed that only A. odocoilei was present in deer from 99 counties, only A. pursglovei in deer from 25 counties, and both species in deer from 28 counties. Both A. odocoilei and A. pursglovei were found in Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, and Virginia. Apteragia odocoilei also occurred in Maryland, Tennessee, West Virginia, Texas, Oklahoma, New Jersey, and the Virgin Islands.     

Parasites, diseases and health status of sympatric populations of sambar deer and white-tailed deer in Florida

From December 1983 to December 1984 a study on parasites, diseases and health status was conducted on sympatric populations of sambar deer (Cervus unicolor) and white-tailed deer (Odocoileus virginianus) from St. Vincent Island, Franklin County, Florida. Ten sambar and six white-tailed deer were examined. White-tailed deer had antibodies to epizootic hemorrhagic disease virus and bluetongue virus. Serologic tests for antibodies to the etiologic agents of bovine virus diarrhea, infectious bovine rhinotracheitis, vesicular stomatitis, parainfluenza 3, brucellosis, and leptospirosis were negative in both species of deer. White-tailed deer harbored 19 species of parasites; all were typical of the parasite fauna of this species in coastal regions of the southeastern United States. Sambar deer harbored 13 species of parasites, which apparently were derived largely from white-tailed deer. The only exception was Dermacentor variabilis which occurs frequently on wild swine on the island. The general health status of sambar deer appeared to be better than that of white-tailed deer. This was hypothesized to result from the sambar deer's utilization of food resources unavailable or unacceptable to white-tailed deer and to the absence and/or lower frequency of certain pathogens in sambar deer.     

Natural and experimental infection of white-tailed deer (Odocoileus virginianus) from the United States with an Ehrlichia sp. closely related to Ehrlichia ruminantium

An Ehrlichia sp. (Panola Mountain [PM] Ehrlichia sp.) closely related to Ehrlichia ruminantium was recently detected in a domestic goat experimentally infested with lone star ticks (LSTs, Amblyomma americanum) collected from Georgia, USA. The infected goat exhibited pyrexia and mild clinical pathologic abnormalities consistent with ehrlichiosis. At least two other Ehrlichia species (Ehrlichia chaffeensis and Ehrlichia ewingii) are maintained in nature by a cycle involving LSTs as the primary vector and white-tailed deer (Odocoileus virginanus) as a known or suspected reservoir. To investigate the possibility that white-tailed deer are potential hosts of the PM Ehrlichia sp., whole blood samples collected from 87 wild deer from 2000 to 2002 were screened with a species-specific nested PCR assay targeting the citrate synthase gene. In addition, two laboratory-raised white-tailed deer fawns were each infested with 120 wild-caught LST adults from Missouri, USA, and blood samples were periodically collected and tested for the PM Ehrlichia sp. Of 87 deer tested from 20 locations in the southeastern United States, three (3%) deer from Arkansas, North Carolina, and Virginia were positive for the PM Ehrlichia sp. Wild-caught ticks transmitted the PM Ehrlichia sp. to one of two deer fawns, and colony-reared nymphal LSTs acquired the organism from the deer, maintained it transstadially as they molted to adults, and transmitted the PM Ehrlichia sp. to two na?ve fawns. These findings indicate that white-tailed deer are naturally and experimentally susceptible to infection with an Ehrlichia sp. closely related to E. ruminantium and are able to serve as a source of infection to LSTs.     

Molecular characterization of Cryptosporidium sp. isolated from northern Alaskan caribou (Rangifer tarandus)

Cryptosporidium sp. was found in 3 out of 49 caribou (Rangifer tarandus) from northern Alaska. Segments of both the 18S ribosomal RNA and the heat shock protein genes were amplified from the caribou isolate and compared with that obtained from an isolate from a wild white-tailed deer (Odocoileus virginianus) in Virginia as well as other species and isolates available from GenBank. Analyses showed the white-tailed deer isolate to be identical with the C. parvum cattle genotype; however, the caribou isolate represents a new genotype closely related to C. serpentis, C. muris, and C. andersoni. Giardia sp. was not detected in any of the caribou samples nor was Cryptosporidium sp. or Giardia sp. detected in any of the 42 moose (Alces alces) samples examined.     

Survival,cause-specific mortality,and population growth of white-tailed deer in western Virginia

Understanding the role of recruitment in population dynamics of white-tailed deer (Odocoileus virginianus) is important for management. In the central Appalachian Mountains, deer are part of a largely forested ecosystem that supports 3 carnivore species thought to be capable of influencing white-tailed deer recruitment: black bears (Urus americanus), coyotes (Canis latrans), and bobcats (Lynx rufus). Yet little is known about predation, how other environmental factors influence recruitment, or the importance of neonate survival to white-tailed deer population performance in the region. Our objectives were to identify causes of mortality for neonates, analyze effects of landscape attributes on survival of neonates, estimate survival rates for neonates and adult female white-tailed deer, and to model population growth trends based on current vital rates and hypothetical harvest and neonate survival scenarios. During 2019–2020, we captured 57 neonate deer in Bath County, Virginia, USA, by monitoring 38 pregnant females equipped with global positioning system collars and vaginal implant transmitters and by conducting transect searches for recently born neonates. We observed 37 neonate mortalities and identified cause of death using field and genetic evidence. Mortalities included 28 predation events and 9 deaths from other causes (e.g., abandonment, malnutrition, disease). Black bears accounted for 48.6% of neonate mortalities, and 64.2% of predation events (n = 18), followed by bobcats (n = 5) and coyotes (n = 3). Annual survival for adult female deer was 0.871 and neonate survival to 12 weeks old was 0.310. Elevation was a significant predictor of neonate survival; mortality risk increased 20% for every 100-m increase in elevation. Models of annual population growth using observed vital rates predicted an increasing population (λ = 1.10). A 10% increase in female harvest would still result in a potential population increase of 2% (λ = 1.02), but a 20% increase in harvest rate would result in a potential 7% decline (λ = 0.93). Neonate survival was higher near fertile valley bottoms and lower along forested ridges characterized by shallow, infertile soils and limited edge or early successional forests. While predation, largely influenced by black bears, was the leading cause of neonate mortality and contributed to low neonate survival, we observed little evidence of population decline, and suggest there is opportunity for a modest increase in harvest of female deer.     

Establishment of adult Parelaphostrongylus tenuis, patent infections, and acquired immunity after experimental infection of white-tailed deer (Odocoileus virginianus) and red deer (Cervus elaphus elaphus)

Experimental Parelaphostrongylus tenuis infections were established in white-tailed deer (Odocoileus virginianus) and an atypical host, red deer (Cervus elaphus elaphus). Groups of deer were fed 10, 25, or 100 third-stage larvae (L3) of P. tenuis and received a single equivalent challenge exposure at varying intervals. Infections were monitored up to 6 yr in white-tailed deer and up to 2.8 yr in red deer. The prepatent period in white-tailed deer varied from 91 to 1,072 days (381 +/- 374) and in red deer from 105 to 358 days (167 +/- 77). Adult worms lived for up to 6 yr in white-tailed deer. Although most had patent infections until necropsy, latent periods were observed regardless of season. Adult worms lived for up to 2.8 yr in red deer, and patent infections persisted for 20-363 days (152 +/- 106). Patent infections were correlated with the presence of adult worms in blood vessels and sinuses of both deer species. Worms were restricted to the subdural space in all deer with latent and occult infections. Adult worm recovery in white-tailed deer fed 10 or 25 L3 corresponded to the mean intensities reported in natural infections of white-tailed deer Recovery from deer fed 100 L3 was not typical of natural infection intensities. Adult P. tenuis established in all groups of red deer, but neurologic disease was restricted to animals fed 100 L3. Acute neurologic disease was associated with subdural hemorrhage and occurred at 11 mo postinfection in 2 red deer. The absence of postchallenge patent periods and the persistence of occult infections indicated that challenge exposures did not establish. These data indicate that acquired immunity to P. tenuis was established by 6 mo postinfection in both white-tailed and red deer. Latent periods in white-tailed deer and latent infections in red deer reinforce the need for a reliable diagnostic assay.     

Hematology, blood chemistry and selenium values of captive pronghorn antelope, white-tailed deer and American bison

Pronghorn were observed to have a significantly higher whole blood selenium concentration than either the white-tailed deer or bison. Pronghorn colloid values were significantly less than those of the bison, and approached statistical significance for the white-tailed deer. Differential white blood cell counts for the white-tailed deer were markedly different from those of the pronghorn and bison. The American bison had significantly higher cortisol values and lower T3 values than either the white-tailed deer or pronghorn.     

Leptospiral antibodies in white-tailed deer of the southeastern United States

Serum samples from 1,544 white-tailed deer (Odocoileus virginianus) collected in nine southeastern states were examined for leptospiral antibodies. Significant titers of 1:100 or greater were found in 292 deer. The highest prevalence of leptospiral antibodies was in Virginia, where 108 of 351 deer had significant titers. The most frequently encountered serotypes of Leptospira interrogans were: grippotyphosa (210 positive), pomona (81), and canicola (26). Other serotypes disclosed were australis (15), icterohaemorrhagiae (10), pyrogenes (6), tarassovi (hyos) (5), georgia (4), ballum (4), sejroe (3), bataviae (2) and autumnalis (2).     

Parasites and condition of coexisting populations of white-tailed and exotic deer in south-central Texas.

We examined the parasites and physical condition of coexisting white-tailed deer (Odocoileus virginianus), axis deer (Axis axis), fallow deer (Dama dama), and sika deer (Cervus nippon) on the YO Ranch (Kerr County, Texas, USA) during December 1982 to January 1984. White-tailed deer harbored 12 species of parasites. Exotic deer were infected with nine species of parasites. All parasites recovered from exotic deer and white-tailed deer have been reported from white-tailed deer. Exotic deer had higher condition ratings than white-tailed deer.     

Prevalence of antibodies to Neospora caninum in white-tailed deer,Odocoileus virginianus,from the southeastern United States

Serum samples from 305 white-tailed deer (Odocoileus virginianus) from 14 states in the southeastern United States were examined for antibodies to Neospora caninum using a direct agglutination test. Positive agglutination titers were found in 145 (48%) of the white-tailed deer examined: 21 (7%) had titers of 1:25, 92 (30%) had titers of 1:50, and 32 (10%) had titers of > or = 1:500. These findings that antibodies to N. caninum are common in white-tailed deer support the concept that a sylvatic cycle might exist for this economically important parasite of domestic cattle.     

Correlates of variation in deer antler stiffness: age, mineral content, intra-antler location, habitat, and phylogeny

To test correlations between the stiffness of deer antler and aspects of cervid ecology, we measured the stiffness (in bending) of antler from white-tailed deer ( Odocoileus virginianus ) and compared our results to previous measurements from antlers of other cervid species. Stiffness of antler specimens did not correlate significantly with mineral content or the location within the antler from which specimens were taken in O. virginianus. However, antler stiffness in white-tailed deer decreased significantly between two- and three-year-old bucks, matching the time in O. virginianus life history when males shift from sparring with mostly larger individuals to sparring with mostly smaller individuals. Stiffer antlers may enable younger, smaller bucks to have a more effective lever through which their smaller muscular forces can be transmitted during sparring with older, larger bucks. The stiffnesses we measured for white-tailed deer antler are similar to values measured previously from other members of the odocoileine lineage, which are lower than those previously measured from the antlers of deer living in tropical habitats. However, confidence limits for maximum likelihood reconstructions of the ancestral stiffness of deer antler span the range of high stiffnesses found among tropical deer; furthermore, parsimony-based reconstructions of ancestral antler stiffness are equivocal. Thus, the high antler stiffnesses of tropical deer may reflect the retention of an ancestral condition, rather than adaptation to year-round antler use.     

Culture and serologic survey for Mycobacterium avium subsp. paratuberculosis infection among southeastern white-tailed deer (Odocoileus virginianus)

From July 1998 through October 2002, radiometric culture (ileocecal lymph node, mesenteric lymph node, and feces) and serologic testing by enzyme-linked immunosorbent assay (ELISA) were used to survey white-tailed deer (Odocoilens virgianus) from the soutlheastern United States for infection by Mycobacterium avium subsp. paratuberculosis (Mptb), the causative agent of paratuberculosis (Johne's disease). Mycobacterium avium subsp. paratuberculosis was isolated from the ileocecal lymph node of one of 313 deer (0.3%) originating from 63 populations in Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, and West Virginia (USA). Six deer (2%), all from different populations, had ELISA results above a 0.25 sample-to-positive cutoff value, but none of the ELISA reactors originated from the population from which the single Mptb isolation was made. These six deer were seronegative when tested by agar gel immunodiffusion (AGID). Collectively, these data indicate that white-tailed deer currently do not constitute a broad regional reservoir for Mptb; however, further study is warranted to clarify the significance, if any, of infected deer to the epizootiology of paratuberculosis on a local scale. Adaptation and validation of an ELISA or another serologic assay for use with deer and other wildlife would markedly enhance Mptb surveillanece among wild populations and would be a powerful tool for gaining information on the role of wild species in epidemiology of paratuberculosis.     

Survey of hepatic and pulmonary helminths of wild cervids in Alberta, Canada

During the 1988 hunting season, livers and lungs from 263 mule deer (Odocoileus hemionus hemionus), 198 moose (Alces alces), 147 white-tailed deer (Odocoileus virginianus), and 94 wapiti (Cervus elaphus nelsoni) from Alberta (Canada) were collected for parasitological examination. Most of the samples (89%) were submitted by big game hunters throughout the province. Giant liver fluke (Fascioloides magna) was found in 9% of 22 yearling and 29% of 65 adult wapiti; 4% of 161 adult moose; and 2% of 97 adult white-tailed deer. The intensity of infection generally was low; however, one wapiti had over 600 flukes in the liver. Infections were restricted to alpine and montane regions in southwestern Alberta (97%) as well as boreal uplands of the Cypress Hills in southeastern Alberta (3%). Other parasites recorded included Taenia hydatigena cysts in liver of 61% of 191 moose and 14% of 247 mule deer. Dictyocaulus viviparus was found in lungs of 14% of 50 moose, 14% of 118 mule deer, 12% of 41 wapiti, and 6% of 54 white-tailed deer. Echinococcus granulosus cysts were found in lungs (and occasionally liver) of 37% of 51 moose. Incidental infections of Thysanosoma actinoides, Orthostrongylus macrotis, and Taenia omissa were recorded. Adult Dicrocoelium dendriticum were collected from liver of two wapiti, one mule deer, and one white-tailed deer from the Cypress Hills.     

Meningeal worm in free-ranging deer in Nebraska

The meningeal worm (Parelaphostrongylus tenuis) was found in 22 (7%) of 300 white-tailed deer (Odocoileus virginianus) (257 adults, 43 fawns) examined from Nebraska (USA) during November 1996. None of 53 mule deer (Odocoileus hemionus) (47 adults and 6 fawns) examined were infected. Twenty-two white-tailed deer from 18 counties in eastern Nebraska were infected with Parelaphostrongylus tenuis. This is the first record of P. tenuis in white-tailed deer from this state.     

Prevalence and isolation of Toxoplasma gondii from white-tailed deer in Alabama

Nineteen white-tailed deer (Odocoileus virginianus) from 5 counties in Alabama were examined for infection with Toxoplasma gondii. Twenty-gram samples of heart tissue were bioassayed in mice, serum was examined for T. gondii antibodies using the direct agglutination test, and sections of heart muscle were examined histologically for tissue cysts. Toxoplasma gondii was isolated from 4 of 19 (21%) white-tailed deer hearts. Antibody titers of greater than or equal to 1:50 were found in sera from 7 of 16 (44%) white-tailed deer. Histological examinations of tissue sections from white-tailed deer hearts were negative for T. gondii.