Abstract

From 1992 through 1997, 20 wild Siberian tigers (Panthera tigris altaica) and seven wild Amur leopards (Panthera pardus orientalis) were captured, darted, and immobilized 36 times and 10 times, respectively, for radio-telemetry studies in the Russian Far East.² Initially, all 27 animals were captured with Aldrich spring-activated foot snares (Margo Suppliers, High River, Alberta, Canada), then immobilized and radio-collared. Subsequently, six of the 20 radio-collared tigers were re-darted and immobilized from a helicopter for re-collaring.

Tigers and leopards were darted for immobilization using 3-ml plastic darts and 1.5 mm × 38-mm collared needles projected from a CO₂ powered rifle (Telinject USA, Saugus, CA 91350 USA). Both species were immobilized with an initial dose of 6.6 mg/kg ketamine (Fort Dodge Laboratories, Inc. Fort Dodge, IA 50501 USA) mixed with 0.66 mg/kg xylazine (Bayer Corporation, Shawnee Mission, KS 66201 USA).¹ Anesthesia was maintained with supplements of 1.1 mg/kg ketamine. Seizures during immobilization were observed 22 times in 15 tigers, and once in one leopard, and were managed with 0.07–0.2 mg/kg diazepam (Roche Pharmaceuticals, Nutley, NJ 07110 USA) IV. Anesthesia was reversed in both species with 0.04–0.13 mg/kg yohimbine (Lloyds Laboratory, Shenandoah, IA 51601 USA). Blood and tissue samples were taken during each immobilization. Fecal samples were collected sporadically and yielded no evidence of gastrointestinal parasites. Ticks (Dermacentor and Ixodes spp.) were found on six tigers and two leopards.

Packed cell volumes were determined in the field using microhematocrit samples spun in a bench top centrifuge. Serum samples were frozen and transported to the United States for analysis using an automated analyzer (Hitachi 717 Automatic Analyzer, Roche Diagnostics, Indianapolis, IN 46250 USA). Serum chemistries for wild tigers were compared to results from captive tigers (Table 1). Sixteen of the 20 blood parameters tested between wild and captive tiger populations were significantly (p≤0.05) different. Serum chemistries for wild leopards were compared to results from captive leopards (Table 2). Eight of the 20 blood parameters tested between wild and captive leopard populations were significantly (p≤0.05) different.

Table 1. Serum chemistry values for wild Siberian tigers in the Russian Far East, and captive tigers

^aMedArks, International Species Inventory System, Apple Valley, MN 55124 USA.

Noticeable differences in hematocrit values between the wild and captive populations may be due to a number of things including the type of centrifuge used, centrifuge speed and cycle variations due to the use of a generator for wild samples, and environmental differences between captive and wild cats. In particular this difference may reflect that most captures were done in the winter when there is limited water availability for the wild populations as compared to the captive population which always has water freely available.

Infectious disease serology tests were performed (Washington Area Disease and Diagnostic Laboratory, Pullman, WA 99165 USA) for feline leukemia virus antigen (ELISA), and antibodies to feline enteric coronavirus/feline infectious peritonitis (FECV/FIP; IFA), feline immunodeficiency (ELISA), canine distemper virus (CDV; virus neutralization, and feline panleukopenia (IFA) viruses. Serology antibody tests for Bartonella henselae (Western Blot) were also performed (National Veterinary Laboratory, Inc., Franklin Lakes, NJ 07417 USA). Results are presented in Table 3.

Table 2. Serum chemistry values for wild Amur leopards in the Russian Far East, and captive leopards

^aMedArks, International Species Inventory System, Apple Valley, MN 55124 USA.

Table 3. Serologic tests performed on wild Siberian tigers and Amur leopards in the Russian Far East (number of positive animals and number of animals tested)

^aImmunofluorescent antibody test.
^bVirus neutralization test.

These data supply the first baseline information on free-ranging animals for comparison to captive populations of two highly endangered felids. Contrasts in serum chemistry results, or seroprevelance of disease may be indicators of potential conservation threats from human impacts requiring further investigation. The antibody titers to CDV, FECV/FIP, Bartonella henselae, and panleukopenia detected in these cats may reflect the endemic presence of these viruses in the wild population or may reflect exposure through predation on infected domestic animals. In either case these viruses may pose a significant threat to the wild populations,² and the presence of antibodies warrants further investigation.

Literature Cited

1.  Goodrich, J.M., L.L. Kerley, B.O. Schleyer, D.G. Miquelle, K.S. Quigley, Y.N. Smirnov, I.G. Nikolaev, H.B. Quigley, and M.G. Hornocker. 2001. Capture and chemical anesthesia of Amur (Siberian) tigers. Wildl. Soc. Bull., in press.

2.  Roelke-Parker, M.E., et al. 1996. A canine distemper virus epidemic in Serengeti lions (Panthera leo). Nature 379:441.