Xylazine hydrochloride for immobilizing captive white-tailed deer (Odocoileus virginianus)

White-tailed deer (Odocoileus virginianus) were immobilized with intramuscular doses of xylazine hydrochloride to facilitate blood sampling. Injection was either remotely by modified dart syringe or manually by hand syringe. In 86 attempts to immobilize female deer (aged 2, 5–6 yr) 73.3% were effectively immobilized for 90 min while 108 attempts to immobilize male deer (aged 2–3 yr) for at least 30 min resulted in 94.4% effective immobilization. Induction times averaged approximately 10 min for both sexes. Treated deer exhibited sedation, hypothermia, reduced respiration rates, anorexia, salivation, tongue paralysis and diarrhea. Deer also showed a loss or partial loss of pedal, palpebral, corneal, and swallowing reflexes during immobilization. Side effects of xylazine and length of immobilization appeared to be dose dependent. Mortality as a result of xylazine immobilization was four male deer out of a total of 194 immobilizing attempts on both sexes. Recommendations are given concerning care of deer during immobilization and recovery.     

Rumen Ciliate Protozoa in Ohio White-tailed Deer (Odocoileus virginianus)

ABSTRACT. Rumen contents were obtained from 23 white-tailed deer (Odocoileus virginianus), located in the eastern portion of central Ohio. Samples were taken during late fall and winter over a 4-yr period, 1986–1990. Protozoan numbers ranged from 0.002 to 7.25 × 10⁶ per ml of rumen contents, with a mean of 2.96 × 10⁶. Six deer had protozoan concentrations higher than any values previously reported in ruminants. In all 23 animals, Entodinium dubardi was the only ciliate protozoan species present.     

Congenital osteopetrosis in white-tailed deer (Odocoileus virginianus)

Inferior brachygnathia in neonatal fawns occurred sporadically over a 10 yr period in a captive herd of white-tailed deer (Odocoileus virginianus) in southern Ontario. Two fawns submitted for necropsy had marked inferior brachygnathia, protruding tongues, and fractured long bones. Radiographs of the limbs revealed longitudinal striations of relatively translucent immature woven bone that caused loss of distinction between medullary cavities and cortices. Microscopically, there was failure of remodelling of the primary spongiosa and filling of the medulla by cone-shaped chondro-osseous cores. The findings supported a diagnosis of osteopetrosis, usually a hereditary disease characterized by absence of marrow cavities as a result of defective bone remodelling. Osteopetrosis has not been reported previously in deer.     

White-tailed deer (Odocoileus virginianus) fecal pellet decomposition is accelerated by the invasive earthworm Lumbricus terrestris

Exotic European earthworms have expanded into worm-free forests of the United States. Concurrently, populations of the white-tailed deer, Odocoileus virginianus, have also increased. During winter, deer use hemlock stands for cover while browsing elsewhere, creating a net organic matter flux into these stands. Deer fecal pellets can provide annual inputs of 48.1 kg C, 1.4 kg N, and 1.3 kg Ca per hectare. We tested the hypothesis that these pellets were readily consumed by invading earthworms. The litter-feeding anecic earthworm Lumbricus terrestris redistributed fecal pellets and accelerated mass and nutrient loss rates. These losses are likely due to the combination of enhanced fragmentation and decomposition as earthworms drag pellets into their burrows for consumption. This nutrient subsidy may be an important source of high quality “litter” input to hemlock stands, which may in turn facilitate the invasion of these stands by earthworms under high deer densities.     

Hyperkalemia in free-ranging white-tailed deer (Odocoileus virginianus)

Sixty adult and yearling female white-tailed deer (Odocoileus virginianus) were collected in July 2008 (n=30) and March 2009 (n=30) from eastern North Carolina as part of a population health assessment. During July 2008, standard serum analyses revealed hyperkalemia in all deer sampled. In March, the effect of processing time as a possible source of the hyperkalemia was investigated. For a subset of deer (n=10), blood tubes were centrifuged and processed at four time points (0, 30, 60, and 120 min) postcollection. Delayed centrifugation and plasma separation did not affect potassium (K(+)) concentration over time, indicating that a shift in intracellular K(+) did not occur and the hyperkalemia was not due to improper sample handling. Potassium levels were negatively correlated with age and varied across collection periods. Also, K(+) levels were positively correlated with glucose and not correlated with creatine kinase (CK). No single variable indicated a strong enough relationship to explain the hyperkalemia in the study.     

Paratuberculosis in key deer (Odocoileus virginianus clavium)

Paratuberculosis was diagnosed in an endangered Key deer (Odocoileus virginianus clavium) in November 1996. Between 10 April 1997 and 28 September 2000, the Key deer population was monitored for infection with Mycobacterium avium subsp. paratuberculosis by necropsy of available carcasses (n = 170), fecal cultures, and serology. One additional clinically affected Key deer was discovered in July 1998, and M. avium subsp. paratuberculosis was cultured from the feces of one live, asymptomatic deer. The results of this study provided sufficient evidence to consider the Key deer herd infected with M. avium subsp. paratuberculosis at very low prevalence.     

Pulmonary mycoplasmosis in farmed white-tailed deer (Odocoileus virginianus)

An outbreak of respiratory disease at a farmed cervid facility resulted in isolation and identification of Mycoplasma boris in four affected white-tailed deer (Odocoileus virginianus) fawns. Microscopically, pulmonary lesions similar to those associated with M. bovis infections in calves, inclulding lymphoplasmacytic peribronchiolar cuffing and caseonecrotic bronchiectasis, were present. Arcanobacterium pyogenes was recovered from lung tissue as well. This report indicates that M. bovis can be associated with respiratory disease in white-tailed deer.     

Theileriosis in a white-tailed deer (Odocoileus virginianus) fawn

A white-tailed deer (Odocoileus virginianus) fawn was collected in Missouri (USA) and submitted for diagnostic evaluation. Necropsy and histologic examination revealed severe Amblyomma americanum infestation, pronounced icterus, and marked hemosiderin deposition in the liver and spleen. Whole blood evaluation revealed a normocytic normochromic anemia and a piroplasm parasitemia of approximately 70%. The piroplasm was identified as Theileria cervi by polymerase chain reaction and sequencing of the V4 variable region of the 18S rRNA gene from a paraffin-embedded section of lung. Although T. cervi parasitemias have been commonly reported in healthy white-tailed deer, the severe parasitemia in this fawn may have contributed to overt clinical disease, perhaps as part of a combined malnutrition and parasitemia syndrome.     

Maxillary lymphosarcoma in a white-tailed deer (Odocoileus virginianus)

In 1996, lymphosarcoma was observed in a captive adult female white-tailed deer (Odocoileus virginianus) from northeastern Kansas (USA). A subcutaneous mass on the deer's left cheek was surgically removed and lymphosarcoma was diagnosed. The mass recurred within 3 wk. A second surgical removal was attempted but the tumor had grown much larger, had become intimately involved with the buccal mucosa, and was beginning to interfere with mastication. For these reasons, the deer was euthanized. At postmortem examination the only abnormal findings were the primary tumor and enlarged ipsilateral parotid and mandibular lymph nodes. Histologically these tissues demonstrated changes characteristic of lymphosarcoma but no other organs had evidence of neoplastic disease. A diagnosis of focal lymphosarcoma with local metastasis was made. The organ distribution of lymphosarcoma in this deer differs from previously described cases of lymphosarcoma in cervids.     

Cranial suture complexity in white-tailed deer (Odocoileus virginianus)

Neurocranial expansion and mastication are commonly implicated as the two major biomechanical factors affecting suture morphology. In deer the antlers provide an additional source of biomechanical stress acting on the skull. Equivalent stresses are not found in females, who lack antlers. We analyzed the complexity and interdigitation of the interfrontal and coronal sutures that surround the antler-bearing frontal bones of (n = 67) white-tailed deer (Odocoileus virginianus) to 1) evaluate changes in suture morphology throughout ontogeny, and 2) test the hypothesis that male deer have more complex sutures than females. Two methods were used to quantify suture morphology: fractal analysis and length-ratios (actual suture length divided by direct straightline length). Both techniques produced similar results, although the two methods cannot be considered equivalent. Suture complexity increases markedly throughout ontogeny, but appears to level off after animals have reached adulthood. Cranial size in males, but not females, continues to increase in adults. No significant increase in suture complexity with age in the adult cohort was detected. While deer are highly dimorphic in size and the presence of antlers, no significant differences existed between males and females for any measure of suture complexity. No consistent patterns emerged between suture complexity and skull size or antler characteristics. The presence of antlers appears to have a minimal effect on suture complexity in white-tailed deer. Factors that may contribute to the lack of dimorphism in suture complexity are discussed.     

Staphylococcal arthritis in a white-tailed deer (Odocoileus virginianus)

A five and one-half year old deer (Odocoileus virginianus) developed an ankylosing periarticular hypertrophic arthritis due to a coagulase positive staphylococcus infection. Complete encasement of the tibio-tarsal (hock) joints with a hypertrophic, and porous osseous mass had occurred with complete loss of articular cartilage. The pathologic alterations of the tissues are compared to those occurring in swine due to Erysipelothrix insidiosa infection which produces a rheumatoid-like arthritis.     

Cranial osteochondroma in a white-tailed deer (Odocoileus virginianus)

A large osteochondroma of the skull was diagnosed in a young adult free-ranging white-tailed deer (Odocoileus virginianus) from Wyoming. The 4.8-kg neoplasm primarily involved the left frontal bone with extension into the cranial cavity. Microscopically, the neoplasm was composed of well differentiated trabecular bone and islands of cartilage. This neoplasm is rare in domestic species and has not been reported in cervids. Though benign in morphology, the location and size of the neoplasm was probably responsible for debilitation of the deer.     

Use of albendazole in feed to control Fascioloides magna infections in captive white-tailed deer (Odocoileus virginianus)

Thirty-six adult white-tailed deer (Odocoileus virginianus) naturally infected with Fascioloides magna were captured and randomly assigned to four groups. Each group was fed pelleted feed coated with albendazole for each of seven consecutive days to deliver the drug at a dose rate of approximately 0.0, 5.0, 8.5, or 16.5 mg/kg bodyweight/day. At 7 wk posttreatment, each animal was euthanized and necropsied. Effects of albendazole treatment included significant reduction (P less than 0.05) in parasite egg count per gram of feces and increase in serum albumin concentration (P less than 0.05). Smaller parasites or remains of dead parasites were seen at the end of migratory tracks in the treated groups. Efficacy of the drug was 82 to 84%.     

Atlantoaxial instability in a white-tailed deer fawn (Odocoileus virginianus)

On 14 March 2001, an 8 mo old, male white-tailed deer (Odocoileus virginianus) was found in lateral recumbency exhibiting neurologic signs including inability to rise, opisthotonus, paddling, and respiratory distress. There was evidence of minor cranial trauma. Postmortem examination revealed atlantoaxial instability with ventral deviation of the axis due to malformation of the caudal atlas and cranial axis. Given the age of the fawn, the instability was assumed to be congenital with minor trauma inducing severe, acute neurologic signs.     

Effects of fluoride ingestion on white-tailed deer (Odocoileus virginianus)

The effects of the addition of 25 or 50 ppm fluoride (F), as sodium fluoride (NaF), to the rations of 5-mo-old male white-tailed deer were similar to those observed in domestic cattle fed similar amounts of fluoride. The ingestion of 50 ppm F for 2 yr resulted in the accumulation of over 7,000 ppm F in bone ash. Accumulation of fluoride in antlers was extensive and occurred more rapidly than in skeletal tissue. Fluoride ingestion resulted in lesions on the developing incisors that were similar, but not identical to those seen in other species. Increased molar wear in the deer fed 50 ppm F was minimal, and no gross pathology of the mandible was observed. Only mild hyperostosis of the long bones was evident.     

Genetic consequences of white-tailed deer (Odocoileus virginianus) restoration in Mississippi

White-tailed deer (Odocoileus virginianus) were nearly extirpated from the southeastern USA during the late 19th and early 20th centuries. Recovery programmes, including protection of remnant native stocks and transplants from other parts of the species' range, were initiated in the early 1900's. The recovery programmes were highly successful and deer are presently numerous and continuously distributed throughout the southeastern USA. However, the impact of the recovery programmes on the present genetic structure of white-tailed deer remains to be thoroughly investigated. We used 17 microsatellite DNA loci to assess genetic differentiation and diversity for 543 white-tailed deer representing 16 populations in Mississippi and three extra-state reference populations. There was significant genetic differentiation among all populations and the majority of genetic variation (> or = 93%) was contained within populations. Patterns of genetic structure, genetic similarity and isolation by distance within Mississippi were not concordant with geographical proximity of populations or subspecies delineations. We detected evidence of past genetic bottlenecks in nine of the 19 populations examined. However, despite experiencing genetic bottlenecks or founder events, allelic diversity and heterozygosity were uniformly high in all populations. These exceeded reported values for other cervid species that experienced similar population declines within the past century. The recovery programme was successful in that deer were restored to their former range while maintaining high and uniform genetic variability. Our results seem to confirm the importance of rapid population expansion and habitat continuity in retaining genetic variation in restored populations. However, the use of diverse transplant stocks and the varied demographic histories of populations resulted in fine-scale genetic structuring.     

Gastro-intestinal helminths in white-tailed deer (Odocoileus virginianus) of Illinois.

Two deer populations, one in northern Illinois the other in southern Illinois, were examined by necropsy (n = 44 and 40 respectively) for helminth parasites of the gastro-intestinal tract and abdominal cavity. Both herds were parasitized by Apteragia odocoilei, Haemonchus contortus, Gongylonema pulchrum, Setaria yehi, Trichuris ovis, and Moniezia benedeni. Nematodirus sp. was found only in deer of northern Illinois. Ostertagia mossi, Capillaria sp., Cooperia sp., and Oesophagostomum sp. were found only in deer of southern Illinois.     

Morbidity and mortality factors in key deer (Odocoileus virginianus clavium)

The population health of endangered Key deer (Odocoileus virginianus clavium) was monitored from 10 February 1986 to 28 September 2000 by necropsy of animals that were killed by vehicles, euthanized because of terminal injuries or disease conditions, or found dead. The predominant mortality factor during the period was collision with motor vehicles; however, several infectious diseases were diagnosed, including infections with Arcanobacterium pyogenes, Haemonchus contortus, Salmonella spp., and Mycobacterium avium subsp. paratuberculosis. During the period monitored, the only infectious disease that was thought to have affected population dynamics was haemonchosis. Nevertheless, several of the observed diseases have potential to impact viability of the Key deer population under appropriate environmental conditions.