Functional anatomy of the omasum in high Arctic Svalbard reindeer (Rangifer tarandus platyrhynchus) and Norwegian reindeer (Rangifer tarandus tarandus)

The structure and fill of the omasum was investigated in summer and in winter in adult female reindeer living on the polar desert and tundra of the high Arctic archipelago of Svalbard and in sub-Arctic mountain habitats in northern Norway. The mean total mass of the omasum in non-lactating adult female Svalbard reindeer was 467 g (0.65 g per 100 g live body mass (BM)) in September and 477 g (1.03 g per 100 g BM) in April. By contrast, the mean mass of the omasum in non-lactating adult reindeer in northern Norway was 534 g (0.83 g per 100 g BM) in September but only 205 g (0.35 g per 100 g BM p < 0.05) in late March, owing to a decrease in both tissue mass and the wet mass of the contents of the organ. The mean absorptive surface of the omasum in Svalbard reindeer was 2300 cm2 in September and 2023 cm2 in April. In Norwegian reindeer, by contrast, the absorptive surface area decreased from 2201 cm2 in September to 1181 cm2 (p < 0.05) in late March. The marked seasonal decline of omasal tissue and contents in Norwegian reindeer probably results from intake of highly digestible forage plants, including lichens, in winter. Svalbard reindeer, a non-migratory sub-species, survive eating poor quality fibrous vascular plants in winter. The absence of any marked seasonal change in the mass, total absorptive surface area or filling of the omasum in Svalbard reindeer in winter despite a substantial decline in body mass presumably reflects their need to maintain maximum absorption of nutrients, including volatile fatty acids, when feeding on such poorly fermentable forage.     

Systemic nocardiosis in a reindeer (Rangifer tarandus tarandus).

Systemic infection by Nocardia asteroides was diagnosed in a reindeer (Rangifer tarandus tarandus). At necropsy, the animal had enlarged tracheobronchial lymph nodes, pleural and peritoneal effusions, and numerous, multifocal to coalescing, yellow, firm nodules with inspissated pus in the lung, pleura, omentum, liver, heart, adrenal glands, and left kidney. Microscopically, the nodules consisted of foci of pyogranulomatous inflammation. Microscopic lesions were present in the grossly affected organs as well as spleen and brain. Sections stained with Gram and modified Fite-Faraco histochemical stains had numerous gram-positive, variably acid fast, beaded and branching filamentous organisms in the necrotic centers. N. asteroides was isolated from the lung, bronchial lymph nodes, liver, and left kidney. To the authors' knowledge, this is the first report of systemic N. asteroides infection in a reindeer.     

Transplacental toxoplasmosis in a reindeer (Rangifer tarandus) fetus

Toxoplasma gondii infection was diagnosed in a full term stillborn reindeer (Rangifer tarandus) fetus. The fetus had encephalitis and placentitis associated with T. gondii. Tissue cysts were identified histologically in sections of brain and tachyzoites were present in placenta and the myocardium. Protozoa in the brain, heart, and placenta stained positively with T. gondii antibodies, but not with Neospora caninum antibodies in an immunohistochemical test. The dam of the fetus had a 1:12,800 titer to T. gondii in the modified agglutination test employing whole tachyzoites and mercaptoethanol. This is the first confirmed report of T. gondii infection in reindeer.     

Prevalence of echinococcosis in reindeer (Rangifer tarandus) in Sweden

In Sweden echinococcosis is uncommon in domestic animals. In reindeer in the most northern part of the country echinococcosis was found. Of 1453 pairs of lungs, 23 pairs (1.6 %) were infected with hydatid cysts. These were of two types: typical well-developed hydatid cysts, which were found in nine of the 23 infected lungs, and collapsed hydatid cysts, which were found in 13 of the lungs. In only one lung pair both types of cysts were seen.     

Theileriosis in a reindeer (Rangifer tarandus tarandus) associated with a potentially novel Theileria sp

A 5‐year‐old male neutered reindeer (Rangifer tarandus tarandus) from Missouri was presented with a 3‐week history of anorexia, respiratory distress, lethargy, and weight loss. Blood smear review revealed that a small percentage of RBCs contained small (1–2 μm in length) pleomorphic piroplasms (signet ring, rod‐ or pear‐shaped, and elongate forms) with an eccentric magenta nucleus and basophilic cytoplasm. Nested PCR to specifically amplify a portion of the piroplasm small subunit ribosomal RNA (SSU rRNA) gene was performed on DNA extracted from an EDTA specimen of whole blood. Subsequent sequence analyses showed similarity between the reindeer hemoparasite and Theileria spp SSU rRNA gene sequences in the GenBank database, with highest similarity to those of a Theileria sp in a White‐tailed deer from North Texas (AY735132, AY735133). The reindeer and North Texas Theileria sp are genetically distinct from, albeit closely related to, the White‐tailed deer Theileria sp (subsequently referred to as T cervi). To the authors' knowledge, this is the first identification of Theileria of this genotype in a reindeer. Historically, T tarandirangiferis infection was found with associated mortality in reindeer in Russia, but reports predate molecular characterization. Hence, the relationship of T tarandirangiferis with either T cervi or this agent remains unknown. T cervi is not typically pathogenic in White‐tailed deer in the US unless the animal is immune‐compromised by stress or disease; however, mortality from T cervi infection in reindeer has been reported.     

Pestivirus and alphaherpesvirus infections in Swedish reindeer (Rangifer tarandus tarandus L.)

Herding semi-domesticated reindeer has economic and social value for Sami people in the northern territories of Fennoscandia. However, with the intensification of reindeer husbandry, interspecies transmission of pathogens between reindeer and domestic animals may become a problem, especially for countries such as Sweden, Norway, and Finland where pestivirus and alphaherpesvirus have been eradicated in domestic ruminants. This study, which included 1158 Swedish reindeer, showed relatively high prevalence of antibodies against bovine viral diarrhoea virus (BVDV) (32%) and bovine herpesvirus-1 (BoHV-1) (53%). Adult animals were more often seropositive for BVDV and BoHV-1 (50% and 78%, respectively) than were calves (18 and 11%, respectively). While the seroprevalence of alphaherpesvirus was similar in different herding districts, pestivirus seropositivity was highest in the South and diminished towards the North of the Swedish reindeer herding area. High correlation of the seropositivity against both pathogens at both individual and herd levels may indicate possible mutual synergetic effects and may be explained by the immunosuppressive nature of the viruses. While alphaherpesvirus seroprevalence was probably related to putative cervid herpesvirus 2 (CvHV-2), the pestivirus infecting reindeer remains undefined. The virus neutralisation test of reindeer sera using different pestivirus strains, revealed higher titres against Border disease virus strains like 137/4 (BDV-1) and Reindeer-1 (BDV-2) than against BVDV-1. However, the virus was not identified by real time RT-PCR in any of the samples (n=276) from seronegative reindeers. The study showed that pestivirus and alphaherpesvirus infections are endemic in the Swedish reindeer population.     

Wintertime pharmacokinetics of intravenously and orally administered meloxicam in semi-domesticated reindeer (Rangifer tarandus tarandus)

ObjectiveTo investigate the pharmacokinetics of orally and intravenously (IV) administered meloxicam in semi-domesticated reindeer (Rangifer tarandus tarandus).Study designA crossover design with an 11 day washout period.AnimalsA total of eight young male reindeer, aged 1.5–2.5 years and weighing 74.3 ± 6.3 kg, mean ± standard deviation.MethodsThe reindeer were administered meloxicam (0.5 mg kg^–1 IV or orally). Blood samples were repeatedly collected from the jugular vein for up to 72 hours post administration. Plasma samples were analysed for meloxicam concentrations with ultraperformance liquid chromatography combined with triple quadrupole mass spectrometry. Noncompartmental analysis for determination of pharmacokinetic variables was performed.ResultsThe pharmacokinetic values, median (range), were determined. Elimination half-life (t_½) with the IV route (n = 4) was 15.2 (13.2–16.8) hours, the volume of distribution at steady state was 133 (113–151) mL kg^?1 and clearance was 3.98 (2.63–5.29) mL hour^–1 kg^–1. After oral administration (n = 7), the peak plasma concentration (C_max) was detected at 6 hours, t_½ was 19.3 (16.7–20.5) hours, C_max 1.82 (1.17–2.78) μg mL^–1 and bioavailability (n = 3) 49 (46–73)%. No evident adverse effects were detected after either administration route.Conclusions and clinical relevanceA single dose of meloxicam (0.5 mg kg^–1 IV or orally) has the potential to maintain the therapeutic concentration determined in other species for up to 3 days in reindeer plasma.     

Haematology of clinically normal and sick captive reindeer (Rangifer tarandus)

A retrospective analysis of haematological values from clinically normal captive reindeer (Rangifer tarandus) showed that the red cell count, haemoglobin level, packed cell volume and lymphocyte count were higher and the erythrocyte sedimentation rate and eosinophil count were lower in juveniles than in adults. Newborn animals were anaemic compared with juveniles and adults and had high reticulocyte counts. The values from healthy reindeer were used to identify abnormal haematological variations in a number of sick animals. It was shown that reindeer exhibit similar haemopathological responses to those of other artiodactyla, with increases in the erythrocyte sedimentation rate and fibrinogen level being of particular diagnostic significance. Eosinophilia was the only abnormal haematological finding in individuals with subclinical infections of intestinal parasites.     

West Nile virus infection in reindeer (Rangifer tarandus).

West Nile virus (WNV) infection in 4 reindeer (Rangifer tarandus) resulted in lymphohistiocytic encephalomyelitis within the medulla oblongata and cervical spinal cord. Immunohistochemistry revealed WNV antigen within neurons and among mononuclear cell infiltrates. These represent the first known cases of clinical WNV infection in Cervidae. Clinical signs and lesions were similar to those described in horses. Nucleotide sequence of a 768-bp region of the WNV E-glycoprotein gene revealed 1 nucleotide mutation, which resulted in a single amino acid substitution from a serine to a glycine (position 227 of E-glycoprotein) when compared with the prototype WNV-NY99 strain (isolated from Bronx zoo flamingo 382-99).     

Papillar morphology of the rumen of forest reindeer (Rangifer tarandus fennicus) and semidomesticated reindeer (R. t. tarandus)

The papillar morphology of the ventral and dorsal rumen of the wild forest reindeer (Rangifer tarandus fennicus Lönn.) and semidomesticated reindeer (R. t. tarandus L.) was studied in October and November 1996. The morphological measurements which were carried out were: the lengths of the papillae, the number of the papillae per square centimetre, the cross‐sectional area and perimeter of sections cut from the middle of papillae. From these measurements mean papillar volume, areal papillar volume, mean papillar (epithelial) surface area, areal papillar surface and surface enlargement factor were calculated. No differences in these measurements between ventral and dorsal walls of the rumen were evident. The semidomesticated reindeer had longer papillar perimeters, larger mean and areal papillar surface areas, larger mean papillar volumes, and a larger surface enlargement factor in the ventral rumen than did forest reindeer. This may be a result of differences between feeding habits, the semidomesticated reindeer preferring a diet including more plants rich in carbohydrates e.g. lichens, which has resulted in a high production of volatile fatty acids and thus stimulation of papillar growth.     

Medetomidine-ketamine in reindeer (Rangifer tarandus tarandus): effective immobilization by hand- and dart-administered injection.

Twelve reindeer (Rangifer tarandus tarandus) were immobilized by hand injection in indoor stalls with established optimal hand-injection doses of medetomidine-ketamine and then moved to outside paddocks where they were immobilized again with the same dose by dart. The reindeer in paddocks were immobilized a second time with a 50% higher dose, hereafter referred to as the optimal darting dose. Mean time to first sign of sedation was longer and mean induction time was significantly longer (55% and 79%, respectively) when the optimal hand-injection dose was dart injected versus hand injected. Mean time to first sign of sedation was not significantly shorter (although 21% shorter, numerically) but mean induction time was significantly shorter (30%) when animals were darted with the optimal darting dose versus darted with the optimal hand-injection dose. There were no significant differences in respiratory rate, rectal temperature, and relative arterial oxygen saturation in animals injected with different doses and by different routes. but there was a significantly lower heart rate in animals dart injected with the optimal darting dose versus dart injected with the optimal hand-injection dose. All animals responded at similar rates to atipamezole injection.     

Clinical evaluation of established optimal immobilizing doses of medetomidine-ketamine in captive reindeer (Rangifer tarandus tarandus)

OBJECTIVE: To evaluate clinical effects and repeatability of clinical effects for an optimal immobilizing dose of a combination of medetomidine hydrochloride (MED) and ketamine hydrochloride (KET) in reindeer (Rangifer tarandus tarandus). ANIMALS: 12 healthy 6- to 8-month old reindeer. PROCEDURE: Each reindeer was immobilized once with an initial dose (combination of 0.06 mg of MED/kg of body weight and 0.3 mg KET/kg) and twice with an optimal dose of MED-KET. Reversal was achieved with 5 mg of atipamezole/mg of MED injected 45 minutes after MED-KET administration. Observational variables were recorded. Oxygen saturation of arterial hemoglobin measured by pulse oximetry (Spo2), respiratory rate (RR), heart rate (HR), and rectal temperature (RT) were recorded 10, 25, and 40 minutes after immobilization. RESULTS: Mean time to first sign of sedation and time until a recumbent animal lifted its head were significantly reduced for reindeer given the optimal dose, compared with the initial dose. Mean Spo2 remained > 90% during initial immobilization; this value was significantly lower for the optimal dose, but increased during immobilization from 85 to 89%. At all doses, RR increased significantly throughout the recorded period; however, RT and HR were constant. Except for time until reindeer stood, all time variables, Spo2, RR, RT, and HR were repeatable. CONCLUSION AND CLINICAL RELEVANCE: mmobilization of captive reindeer achieved by use of the optimal dose established here is clinically acceptable, although Spo2 should be carefully monitored. Administration of the optimal dose produced the same clinical effect during repeated immobilization of the same reindeer.     

Experimentally induced infection of reindeer (Rangifer tarandus) with Mycobacterium bovis.

In the USA, all species of Cervidae are included in the USDA's uniform methods and rules for the eradication of bovine tuberculosis and, therefore, are subject to regulations regarding intradermal tuberculin testing. In reindeer (Rangifer tarandus), infection with Mycobacterium bovis is exceedingly rare and the response of reindeer to infection with M. bovis in pathologic and immunologic terms is unknown. The objectives of the study reported here were to describe the pathologic changes associated with M. bovis infection in reindeer and evaluate the effectiveness of intradermal tuberculin testing as a means of diagnosis of tuberculosis in reindeer. Thirteen reindeer were inoculated intratonsilarly with 10(5) colony-forming units (CFU) of M. bovis, and 4 noninoculated reindeer served as negative controls. The comparative cervical test (CCT) was done on all reindeer 90 and 240 days after inoculation. Thirteen months after inoculation, all reindeer were euthanized and examined. All experimentally inoculated reindeer developed lesions in the medial retropharyngeal lymph nodes. The CCT accurately identified all M. bovis-inoculated reindeer, but false-positive results were common among negative-control reindeer. Modifications of the method for interpretation of the CCT decreased false-positive results without increasing false-negative results. Reindeer are susceptible to infection with M. bovis; however, lesions are fewer in number, less severe in nature, and less widely disseminated than are those seen in white-tailed deer (Odocoileus virginianus). Comparative cervical skin testing of reindeer can be highly sensitive, but has low specificity. Specificity can be improved by modification of criteria for interpretation of the CCT.     

Ultrastructure of the cysts of Sarcocystis tarandivulpes from skeletal muscle of reindeer (Rangifer tarandus tarandus)

The cysts of S. tarandivulpes were found to be limited by a unit membrane which has been called the cyst membrane. The surface of the cysts was covered by closely packed and hexagonally arranged knob-like protrusions. The protrusions were 0.6–1.2 μm long and had an elliptical cross section. At the base of and between the bases of the protrusions the cyst mem brane was raised into low anastomosing folds which delineated shallow compartments. Between the folds the cyst membrane formed small vesicle-like invaginations into the cyst. On the apical part of the protrusions the cyst membrane had a smooth contour and was underlined by 2 layers of electron-dense material. Cyst ground substance divided the interior of the cyst into compartments containing either metrocytes or cystozoites. Cystozoites undergoing endodyogeny were present among the nondividing cystozoites. Some new terms were introduced to denote structures at the border of the cyst. The old terms are reviewed and the structural resemblance between S. tarandivulpes and S. odocoileocanis from Odocoileus virginianus is discussed.     

The effect of blood sampling method on indicators of physiological stress in reindeer (Rangifer tarandus tarandus)

The effects of manual blood sampling and remote blood sampling using automatic blood sampling equipment (ABSE) on plasma cortisol and catecholamine concentrations were studied on eight adult female reindeer (Rangifer tarandus tarandus). Contemporary body temperatures and heart rates were also recorded to determine their utility as other possible stress indicators. The animals were blood sampled once every hour with ABSE on 9-10 May and then by manual blood sampling on 13-14 May. Animals were also fitted with equipment to record heart rate and body temperature. Heart rate and body temperature were also recorded continuously without blood sampling on 17-18 May in undisturbed control conditions. Plasma cortisol concentrations were five-to-six fold greater during manual blood sampling compared to sampling with ABSE (F(1,3) = 13.34, P < 0.05). Plasma noradrenaline concentrations were significantly higher (F(1,3) = 22.98, P < 0.05) during manual blood sampling compared to sampling with ABSE, whereas plasma adrenaline concentrations did not differ. Heart rate was higher during manual blood sampling compared to control values. Body temperature was significantly higher during manual sampling compared to values recorded without blood sampling (F(1,4)= 31.65, P < 0.01). In conclusion, plasma cortisol concentration provides an excellent indicator of handling stress in reindeer. The use of ABSE for blood sampling enables measurements of plasma cortisol levels close to basal concentrations that may be used for reference values in studies where indicators of physiological stress are required.