Conservation Medicine

Conservation medicine is the day-to-day medical care of the many species and individual animals at Omaha’s Henry Doorly Zoo and Aquarium. With this practice comes a wide range of sciences and disciplines.

The veterinary medical team at Omaha’s Henry Doorly Zoo and Aquarium works with vision and enthusiasm to advance the science of conservation medicine and to provide the information needed to ensure excellent care for the animals in zoos around the world as well as in their natural habitat. Along with an extensive preventative medicine and wellness programs for Omaha's Henry Doorly Zoo and Aquarium’s animal collection, ongoing research is an intrinsic part of conservation medicine and may, in the end, be one of the most important contributions to the conservation of endangered species.

The veterinary staff and their research counterparts at Omaha’s Henry Doorly Zoo and Aquarium have worked on a range of projects investigating such topics as West Nile vaccination protocols, successful reproduction techniques in big cats and nutrition requirements in amphibians.

Omaha’s Henry Doorly Zoo and Aquarium’s medical team is a leader in the investigation of new and currently unsolved disease issues in exotic and endangered species. An example of this is the ongoing study of heart disease in male gorillas. The Zoo, working with local collaborators in the medical community, as well as other zoological institutions, has significantly advanced our understanding of cardiac disease in gorillas. We have worked extensively with conservation initiatives in the field around the world, to help make those programs more effective in protecting animals in their native habitat. Much of this work has involved the development and evaluation of new anesthetic protocols in hoofstock and big cats. The team at Omaha’s Henry Doorly Zoo and Aquarium has been instrumental in the investigation of improved techniques for the immobilization of large ruminants such as gaur. We have worked extensively to improve anesthetic protocols for great apes, including gorillas and for big cats such as lions and tigers. Anesthetic techniques developed at Omaha’s Henry Doorly Zoo and Aquarium are utilized in field programs to immobilize Amur tigers in Russia and lions in Africa for radio collaring, blood sampling and for disease surveys and other conservation activities.

The conservation medicine team at Omaha’s Henry Doorly Zoo and Aquarium strives to provide the best medical programs possible for the animals in our care and to advance the science of conservation medicine whenever possible.

Medical Programs

Facilities

The Zoo's medical facilities opened in 1996. Included is the animal hospital with a treatment/prep area, small animal surgery, scrub room, radiology, dark room, pharmacy, clinical laboratory, animal quarantine and holding rooms, animal isolation, student housing quarters, offices and a nursery. A large animal surgery was added in 2005 through a donation from the Hubbard Family Foundation.

Preventative Health

Annual Exams: Many animals receive an annual examination similar to examinations humans receive. These examinations include an assessment of all major organ systems, blood work, a dental exam, nail or hoof trims and treatment for any health problems. Medical records are maintained and tests similar to those given to humans are made to monitor animal health.

Vaccination Program: Exotic animals can get the same diseases as domestic animals. To help prevent this occurrence, many of the animals at Omaha's Zoo get annual vaccinations just like dogs, cats, horses, cattle, etc. Several examples include rabies and tetanus vaccines for outdoor carnivores, primates and hoof stock and West Nile vaccines for birds and susceptible mammals such as elephants, rhinos, zebras and tapirs. Most canine and feline species receive the same or similar vaccines to those used in cats and dogs for diseases like distemper, parvovirus and feline leukemia.

Dental Health: Carnivores and primates often accumulate tartar on their teeth just like humans do. This requires that the animal's teeth be cleaned on a regular basis (the tartar removed and the teeth cleaned and polished). Occasionally, more serious problems require more complex procedures such as root canals.

Neonate Exam: Many newborn animals at Omaha's Henry Doorly Zoo and Aquarium are examined to check their health, to give them vitamins, their first vaccinations and some kind of individual identification such as an ear tag or microchip.

Procedures

Laparoscopies: This procedure is used to locate internal problems in the least invasive way possible.

Ultrasound: Ultrasound has many uses including determining pregnancy, viewing internal organs non-invasively and locating tumors or abnormal growths to assist in determining if a surgery is necessary rather than doing an exploratory procedure when it is not required.

Root Canals: A healthy set of teeth is important to all animals. Dental disease can cause discomfort, decreased appetite and can lead to disease in other organs including the heart and the kidneys. Rather than performing extractions of broken teeth, root canals are often performed to preserve a tooth and the surrounding gum tissue.

Electroejaculation: Semen can be collected from the males of some species to evaluate fertility and for long term storage. It can then be frozen and cryo-preserved for future use.

CT Scans: Modern technology in medical equipment has greatly assisted in the care of animals. An example of this is with the sea turtle. The sea turtle demonstrated problems in the ability to dive after being hit by a boat propeller. It is very important for turtles to be able to dive to feed, avoid predators and maintain their general health. In this case, the use of a high speed CT scanner assisted the medical team in the diagnosis of the problem which was gas buildup in the large intestine. Although the more elaborate and costly units such as the CT scanner are beyond the resources of Omaha's Zoo, this equipment can occasionally be accessed at human medical and veterinary regional facilities.

Emergencies: With such a large population of animals situations can arise that create medical emergencies. These can include trauma from a fall or conflict between exhibit mates, dystocias (difficulties delivering a baby), sudden illness due to infectious processes such as bacteria or viruses and toxicities from allergies or exposure to foreign substances such as items people may throw into exhibits.

Parasitology

Parasites are ubiquitous in any animal environment, regardless of the husbandry practices and the season or time of year. Just as in domestic cats and dogs, carnivores and other animals such as sea lions are susceptible to heartworm disease and must be placed on a monthly preventative. Hoofstock are at special risk for parasites in the environment since in most zoological institutions, they cannot be moved to other pastures due to lack of space. Medicated feed and other anti-parasitics are utilized to help with this problem.

Anesthesia

General Anesthesia: Most animals at Omaha's Zoo must be anesthetized or tranquilized in order for routine procedures to be performed safely for the people and for the animals.

Face Mask: This is a safe and effective way to anesthetize non-venomous reptiles, birds and small mammals quickly with minimal handling.

Endotracheal Tube: For animals that have a hard time breathing under anesthesia or for longer procedures, an endotracheal tube, like those used in human and small animal anesthesia, provides the anesthesic gas and oxygen directly into the lungs

Remote Darting: For large and dangerous animals or for animals in a big enclosure, remote darting by blow pipe, dart pistol or dart rifle provides a safe way to deliver the anesthetic drugs.

Fish Anesthesia: To anesthetize fish for x-rays or surgery, the anesthetic is put in the water and then pumped through the gills.

Venomous (Poisonous) Snake Anesthesia: Venomous or poisonous snakes periodically need to be handled for examinations and medical care. As the venom from a bite of these snakes may cause serious illness or death, special handling and anesthesia techniques are used for safe restraint. Snakes can be coaxed into a clear plastic tube for visual examination or they can be placed into a clear chamber (box) to anesthetize prior to examination.

Clinical Cases

Gorilla Cardiac Database: Heart disease is one of the leading causes of death in adult male gorillas. Procedures conducted in human medicine such as cardiac echocardiograms performed by cardiac ultrasound in addition to blood work and other diagnostic techniques can help determine the prevalence of this disease in the captive population. It can also help determine what animals need to be on medication, often the same medication used in humans with heart disease.

Sand Tiger Shark: It is common for Sand tiger sharks to develop problems in their vertebral columns resulting in a hump backed appearance. Even though it is known to occur frequently there is little information available on this syndrome and the cause is unknown. Multiple diagnostic tests were conducted including radiographs, ultrasound and blood work in an attempt to gather more information that might help find the answers. Although supportive care and analgesics were provided humane euthanasia was eventually elected due to reduced quality of life.

Publications

Walsh, E., D.L. Armstrong, J. Napier, L.G. Simmons, M. Korte and J. Mcgee. 2008. Acoustic communication in Panthera tigris: A study of tiger vocalization and auditory receptivity revisited. Acoustical Society of Amer. Miami, Fl.

Galeota, J., Napier, J.E., DVM, Armstrong, D.L., DVM and D. Rogers. 2007. Herpesvirus infections in rock hyraxes (Procavia capensis). Amer. Assoc. Vet. Lab. Diag. Reno, Nevada.

Napier, J.E. DVM, N. M. Loskutoff, PhD, S. M. Dankof, L.G. Simmons, DVM and D.L. Armstrong, DVM. 2007. Preliminary data for comparison of carfentanil-xylazine and thiafentanil-medetomidine in electroejaculation of captive gaur (Bos frontalis gaurus). Proc. Am. Assoc. Zoo Vet. Pp. 49 - 50.

Perpinan, D, LV, MSc., J. Martinez, LV., PhD., C. Lopez, LV., E. Carpintero, LV., F. Bargallo, LV., M. Reinacher, Dr. Med. Vet, Dipl. ECVP and A. Ramis, LV., PhD, Dipl ECVP. 2007. Novel viral syndromes in ferrets. Proc. Am. Assoc. Zoo Vet. Pp. 208 - 209.

Zurawka, Heidi S., DVM, Aimee L. Berliner, DVM, Mark L. Hofling, and Stephanie B. James, DVM, Dipl ACZM. Evaluation of three different anesthetic delivery systems in Indian peafowl (Pavo cristatus). Proceedings American Association of Zoo Veterinarians, 2007. Pages 166-167.

Armstrong, D.L., Teaching Tiger: Veterinary Medicine and Technology Transfer in the Conservation of Tigers. Connect, September, 2006. pp 8-10.

Graham, L.H., Byers, A.P., Armstrong, D.L., Loskutoff, N.M., Swanson, W.F., Wildt, D.E. and Brown, J.L. (2006) Natural and gonadotropin-induced ovarian activity in tigers (Panthera tigris) assessed by fecal endocrine analysis. General and Comparative Endocrinology 147:362-370.

Quigley, K.S. and D.L. Armstrong. Tiger management workshop. Primorskaya State Academy of Agriculture, Ussuriisk, Primorskiy Krai, Russia, April 7-22, 2006

Raphael, Bonnie L., DVM, Dipl ACZM, Julie White, DVM, Dipl ACVP, Charolotte Kirk Baer, MS, Stephanie B. James, DVM, Dipl ACZM, Robert P. Moore, DVM, Dipl ABVP-Avian, Kristine M. Smith, DVM, Heidi S. Zurawka, DVM, Paul P. Calle, VMD, Dipl ACZM, and Robert A. Cook, VMD, MPA. “Vitamin E deficiency in multiple species being fed a commercial supplement." Proceedings American Association of Zoo Veterinarians, 2006. Page 13.

Zurawka, Heidi S., DVM, Julie White, DVM, Dipl ACVP, Bonnie L. Raphael, DVM, Dipl ACZM, Paul P. Calle, VMD, Dipl ACZM, Robert P. Moore, DVM, Dipl ABVP-Avian, Kristine M. Smith, DVM, and Stephanie B. James, DVM, Dipl ACZM. “A retrospective study of morbidity and mortality in pudu (Pudu puda) at the Bronx Zoo: 1983-2005." Proceedings American Association of Zoo Veterinarians, 2006. Page 59.

Mercado, J.A., T.G. Curro, D.L. Armstrong and G.E. Duhamel. Colitis in captive tamarins displayed on semi-natural substrate in a mixed species exhibit in a North American zoo. Proceedings of the American Association of Zoo Veterinarians, October 14-21, 2005

Napier, J.E., DVM and T. Moore, DVM. 2005. Chronic Renal Failure and Nephrolithiasis in a two-toed sloth (Choloepus didactylus). Proc. Am. Assoc. Zoo Vet. Omaha, NE. Pp. 83 - 86.

Napier, J.E., DVM, S. Murray, DVM, Dipl. ACZM, M. Garner, DVM, Dipl. ACVP, T. Viner, DVM, Dipl. ACVP and H. Murphy, DVM. 2005. Uterine leiomyomas in three captive eastern bongo (Tragelaphus euruci isaaci). J. Zoo. Wildl. Med. 36: 709-711

Zurawka, Heidi S., “Case report: Gastrointestinal linear foreign bodies in three ebony langurs Trachypithecus auratus." Proceedings Association of Primate Veterinarians (APV) 2005 Annual Workshop, St. Louis, Missouri. (Trainee Travel Grant Award Recipient)

Armstrong, D.L. and L. J. Gage. Very Basic Big Cat Medicine. American Association of Zoo Veterinarians, Wildlife Disease Association and American Association of Wildlife Veterinarians Joint Meeting, August 27-September 3, 2004.

Armstrong, D.L., Crichton, E.G., Dankof, S.M., Schwalbach, L.M.J., Gardner, D.K. and Loskutoff, N.M. (2004) Ovarian stimulation, laparoscopic oocyte retrieval, IVF and blastocyst production using sequential media in the African lion (Panthera leo). Reproduction, Fertility and Development (in press).

Armstrong, D.L., K. Morfeld, A.H. Lewandowski, G. Dumonceaux and K. Quigley. Siberian Tiger (Panthera tigris altaica) species survival plan update. Proceedings of the American Association of Zoo Veterinarians, Wildlife Disease Association and American Association of Wildlife Veterinarians Joint Meeting, August 27-September 3, 2004. 2004

Armstrong, D.L. Veterinary Related Issues. In The Tiger Species Survival Plan (SSP) Report 2003, Felid Taxon Advisory Group (TAG) Mid-Year Meeting. Albuquerque, New Mexico. April 8, 2004. pp 8-12.

Curro, T.G., D. Okeson, D. Zimmerman, D.L. Armstrong and L.G. Simmons. Xylazine-midazolam-ketamine versus medetomidine-midazolam-ketamine anesthesia in captive Siberian Tigers (Panthera tigris altaica). Journal of Zoo and Wildlife Medicine. 35 (3) pp 320- 327, 2004

Graham, L.H., Byers, A.P., Armstrong, D.L., Loskutoff, N.M., Swanson, W.F., Wildt, D.E. and Brown, J.L. 2006. Natural and gonadotropin-induced ovarian activity in tigers (Panthera tigris) assessed by fecal endocrine analysis. General and Comparative Endocrinology 147: 362-370.

Murphy, H., DVM, S. O’Keefe CVT, and J. E. Napier, DVM. 2004. Recapture of an Escaped Western Lowland Gorilla at the Franklin Park Zoo. Rocky Mountain Gorilla Workshop Proc., Calgary Zoo, Calgary, Alberta, Canada.

Quigley, K.S., D.M. Zimmerman and D.L. Armstrong. Tiger management workshop. Primorskaya State Academy of Agriculture, Ussuriisk, Primorskiy Krai, Russia, November 30- December 5, 2004

Zimmerman, D.M., D.L. Armstrong, T.G. Curro, S.M. Dankoff, K.W. Vires, K.K. Cook, N.D. Jaros and M.G. Papich. Pharmacokinetics of Florfenicol after a single intramuscular dose in White-Spotted Bamboo Sharks (Chiloscyllium plagiosum). Proceedings of the American Association of Zoo Veterinarians, Wildlife Disease Association and American Association of Wildlife Veterinarians Joint Meeting, August 27-September 3, 2004.

Armstrong, D.L. Disease risk assessment- essential tool for conservation. Zoos' Print Journal, 18 (5), 1-6. 2003

Crichton, E.G., E. Bedows, A.K. Miller-Lindhom, D.M. Baldwin, D.L. Armstrong, L.H. Graham, J. Ford, J.O. Gjorret, P. Hyttel, C.E. Pope, G. Vajta and N.M. Loskutoff. The efficacy of porcine gonadotropins for repeated stimulation of ovarian activity for oocyte retrieval and in vitro embryo production and cryopreservation in Siberian tigers (Panthera tigris altaica). Biology of Reproduction 68, 105-113. 2003

Simmons, H.A., D.J. Steffen, D.L. Armstrong and D.G. Rogers. Parelaphostrongylus tenuis in captive pronghorn antelope (Antilocapra Americana) in Nebraska. Journal of Wildlife Diseases, 38 (4), 822-825, 2003

Walsh, E.J., D.R. Ketten, L.M. Wang, D.L. Armstrong, T. Curro, L.G. Simmons and J. McGee. Bioacoustics in Panthera tigris. Society of Neuroscience, 33rd Annual Meeting, New Orleans, LA, USA, November 8-12, 2003.

Walsh, E.J., D.R. Ketten, L.M. Wang, D.L. Armstrong, T. Curro, L.G. Simmons and J. McGee. Bioacoustics in Panthera tigris- Hearing and Voice in a Solitary Hunter. First In ternational Conference on Acoustic Communication by Animals. University of Maryland, College Park, MD, USA. July 27-30, 2003.

Walsh, E. J., J. McGee, D.L. Armstrong, T. Curro, L. Song, E. Firbas and N. Feldbauer. Hearing in exotic felids. Assoc. Res. Otolaryngolol. 2003. 26:44

Armstrong, D.L. Tigers, habitat fragmentation and the future potential application of reproductive technology to conservation of the species. Proceedings of the 2nd International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife, Henry Doorly zoo, Omaha, NE, USA, Sept. 28-29, 2002

Armstrong, D., R. Jakob-Hoff and U.S. Seal (Editors). Animal Movements and Disease Risk: A Workbook. 4th edition. Conservation Breeding Specialist Group (SSC/IUCN), Apple Valley, MN. 2002

Gjorret, J.O., E.G. Crichton, N.M. Loskutoff, D.L. Armstrong and P. Hyttel. Ultrastructure of oocyte maturation, fertilization and early embryo development in-vitro in the Siberian tiger (Panthera tigris altaica) Molecular Reproduction and Development 63:79-88. 2002

Armstrong, D. and U.S. Seal (Editors) DISEASE RISK WORKSHOP III, White Oak: Report. June 28-30, 2001. Conservation Breeding Specialist Group (SSC/IUCN), Apple Valley, MN 2001

Hammer, C.J., H.D. Tyler, N.M. Loskutoff, D.L. Armstrong, D.J. Funk, B.K. Lindsey and L.G. Simmons. Compromised development of calves (Bos gaurus) derived from in vitro-generated embryos and transferred interspecifically into domestic cattle (Bos taurus). Theriogenology 55:1447-1455. 2001

Houser, D., L. Simmons, and D. Armstrong. Treatment of an abscessed foot pad of an African Elephant (Loxodonta africana) using a sandal and topically applied chitosan. In The Elephant’s Foot, Iowa State University Press pp 107-114. 2001

Quigley, K.S., D. Armstrong, D.G. Miquelle, J.M. Goodrich and H.B. Quigley. Health Evaluation of Wild Siberian Tigers (Panthera tigris altaica) and Amur Leopards (Panthera pardus orientalis) in the Russian Far East. Proceedings of the American Association of Zoo Veterinarians. September 18-23, 2001. Pp 179-182. 2001

Quigley, K.S., D.L. Armstrong, R. Cook, J. Goodrich, D.G. Miquelle, R.E. Miller and D.L. Janssen. The role of Veterinary Science in Tiger Conservation Issues in Southeast Asia and Russia. Veterinary Conservation Biology: Wildlife Health Management in Australasia, Taronga Zoo, Sydney, Australia. July 2-6, 2001.

Zurawka, Heidi S., DVM, “A Case Report: Metabolic Bone Disease in a Bald Eagle." Proceedings National Wildlife Rehabilitators Association (NWRA) Conference, Lake Tahoe, Nevada, March 2001.

Armstrong, D. and U.S. Seal (Editors). DISEASE RISK WORKSHOP II, New Orleans: Report. September 13-15, 2000. Conservation Breeding Specialist Group (SSC/IUCN), Apple Valley, MN. 2000

Armstrong, D. and Seal, U.S. (Editors) DISEASE RISK WORKSHOP: FINAL REPORT. Omaha, NE March 30- April 1, 2000. Conservation Breeding Specialist Group (SSC/IUCN), Apple Valley, MN: 1- 136 (2000)

Crichton, E.G., Armstrong, D.L., Vajta, G., Loskutoff, N.M. Developmental competence in-vitro of embryos produced from Siberian tigers (Panthera tigris altaica) cryopreserved by controlled rate freezing versus vitrification. THERIOGENOLGY 53:328 (2000)

Gjorret, J.O., Crichton, E.G., Armstrong, D.L., Loskutoff, N.M., Hyttel, P. Oocyte maturation, fertilization and early embryonic development in-vitro in the Siberian tiger (Panthera tigris altaica) THERIOGENOLOGY 53:334 (2000)

Loskutoff, N.M., Armstrong, D.L., Ohlrichs, C.L., Johnson, D.L., Funk, D.J., Van Roekel, P.V., Molina, J.A., Lindsey, B.R., Looney, C.R., Bellow, S.M., Hammer, C.J., Tyler, H.D., Simmons, L.G. Transvaginal ultrasound-guided oocyte retrieval and the developmental competence of in-vitro produced embryos in-vitro and in-vivo in the gaur (Bos gaurus). THERIOGENOLOGY 53:337 (2000)

Morato, R.G., Crichton, E.G., Paz, R.C.R., Zuge, R.M., Moura, C.A., Nunes, A.L.V., Teixeira, R.H., Porto, L., Priscila, M.A.B.V., Guimaraes, S.H.R., Correa, S.H.R., Barnabe, R.C ., Armstrong, D.L., Loskutoff, N.M. Ovarian stimulation and successful in-vitro fertilization in a jaguar (Panthera onca). THERIOGENOLOGY 53:339 (2000)

Seal, U.S. and Armstrong, D.L. (Editors) CONSERVATION ASSESSMENT AND MANAGEMENT PLAN (CAMP) FOR ARABIAN CARNIVORES AND POPULATION AND HABITAT VIABILITY ASSESSMENT (PHVA) FOR THE ARABIAN LEOPARD AND TAHR: FINAL REPORT. Sharjah, United Arab Emirates, February 5-11, 2000, Conservation Breeding Specialist Group (SSC/IUCN) Apple Valley, MN: 1-237 (2000)

Nelson, K.L., Crichton, E.G., Doty, L., Volenec, D., Finnegan, J.M., Morato, R.G., Pope, C.E., Dresser, B.L., Armstrong, D.L., Loskutoff, N.M. Heterologous and homologous fertilizing capacity of cryopreserved felid sperm: a model for endangered species. THERIOGENOLOGY 51:290 (1999)

Armstrong, D. and O. Byers. Western Prairie Fringed Orchid PHVA. CBSG News. (1998) Vol. 9, No.1, pp 6-7.

Armstrong, D. Chemical and Physical Restraint of Cats and Hoofstock; Disease Prevention and Health Maintenance; Reproductive Research and Application. Lectures at SACAVET VIII, College of Veterinary Medicine, University of Sao Paulo, Sao Paulo, Brazil; May 5- 7, 1998.

Armstrong, D. Veterinary Medical Summary.Masterplan Harimau Sumatera Indonesia (Panthera tigris sumatrae). Indonesian Zoological Parks Association, Jakarta, Indonesia, (April, 1998): 39-43.

Houser, D., Simmons, L. and D. Armstrong. The successful recovery of the abscessed foot pad of an African elephant (Loxodonta africana), with particular attention given to two treatment elements: the use of a sandal and topically applied chitosan. First North American Conference on Elephant Foot Care and Pathology, Portland, Oregon, March 20-21, 1998.

Napier, J.E. and P.L. Wolff. 1998. Guidelines for chemical use protocol in animal areas at Disney’s Animal Kingdom. Proc. Am. Assoc. Zoo Vet. Omaha, NE. Pp. 524.

Armstrong, D. and R. E. Miller. South China tiger medical report and recommendations. Third Meeting of the South China Tiger Committee of the Chinese Association of Zoological Gardens. November 19, 1997.

Armstrong, D., M. Fritz and O. Byers (Editors.). Population and Habitat Viability Assessment Workshop for the Western Prairie Fringed Orchid (Platanthera praeclara): Final Report. Conservation Breeding Specialist Group, Apple Valley, MN (1997): 1-127.

Armstrong, D., Simmons, L., Morris, D., Cassidy, D., Loskutoff, N., Brown, C. and E. Louis. Benefits to Omaha’s Henry Doorly Zoo from participation in the Conservation Breeding Specialist Group processes. Conservation Breeding Specialist Group Annual Meeting, August 14-17, 1997.

Chrisman, Cheryl, L., DVM, MS, EdS; Michael Walsh, DVM; John C. Meeks, DVM; Heidi Zurawka, DVM; Richard LaRock, DVM; Larry Herbst, DVM, PhD; Juergen Schumacher, Dr Med Vet. “Neurologic examination of sea turtles." Journal of American Veterinary Medical Association, October 15, 1997.

Masangkay, J.S., Armstrong, D., Citino, S., Escalada, R., Solis, C., Flor, J.A.C.G., Toledo, S., Amido, G. and R. Callo. Chemical immobilization of the tamaraw (Bubalus mindorensis) for semen collection. Proceedings of the Veterinary Practitioners Association of the Philippines, June 19-20, 1997.

Roth, T.L., Armstrong, D.L., Barrie, M.T. and D. E. Wildt. Seasonal effects on ovarian responsiveness to exogenous gonadotrophins and successful artificial insemination in the snow leopard ( Uncia uncia ). Reprod. Fertil. Dev., 1997, 9, pp 285-295.

Tilson, R., Siswomartono, D., Manansang, J., Brady, G., Armstrong, D., Traylor-Holzer, K., Byers, A., Christie, P., Salfifi, A., Tumbelaka, L., Christie, S., Richardson, D., Reddy, S., Franklin, N. and P. Nyhus. International cooperative efforts to save the Sumatran tiger (Panthera tigris sumatrae). In International Zoo Yearbook (1997) Vol. 35: pp 129-138

Armstrong, D., Miller, R., Byers, O., Brady, G., Traylor-Holzer, K. and R.Tilson. International cooperation with range country efforts to conserve tigers (Panthera tigris) and the veterinarians role. Proceedings of the American Association of Zoo Veterinarians Annual Conference, November 3-8, 1996: pp 532-553

Brown, C., Wallner-Pendleton, E., Armstrong, D., Carlson, M. and L. Cuevas. Lead poisoning in captive Gentoo penguins (Pygoscelis papua papua). Proceedings of the American Association of Zoo Veterinarians Annual Conference, November 3-8, 1996: pp 298-301.

de Leon, J., Lawas, N., Escalada, R., Ong, P., Callo, R., Hedges, S., Ballou, J., Armstrong, D. and Seal, U.S.(Editors). Tamaraw (Bubalus mindorensis) Population and Habitat Viability Assessment Report. IUCN/SSC Conservation Breeding Specialist Group: Apple Valley, MN (1996).

Donoghue, A., Byers, A., Johnston, L., Armstrong, D. and Wildt, D. Timing of ovulation after gonadotrophin induction and its importance to successful intrauterine insemination in the tiger (Panthera tigris). Journal of Reproduction and Fertility (1996) 107: pp 53-58.

Manansang, J., Purwantara, B., Gepak, V.H., Masnur, I.Y., Sutarman, Bleyenberg, K., Varadarajulu, R., Hori, H., Duryadi, D. and Armstrong, D. Anoa captive population status and management. In Population and Habitat Viability Assessment Workshop for the Anoas (Bubalus depressicornis and Bubalus quarlesi) Report, Conservation Breeding Specialist Group (SSC/IUCN): Apple Valley, MN (1996): pp. 59-82.

Tilson, R., Armstrong, D., Miller, E., Byers, A., Traylor-Holzer, K., Brady, G., Menghu, W. and Zhong, X. Medical, Reproductive and Management Evaluation of South China Tigers in China. Minnesota Zoo: Apple Valley, MN, 1996: 1-88.

Armstrong, D. Captive Wild Cattle Immobilization Protocol. In Asian Wild Cattle Conservation Assessment and Management Plan Working Document. IUCN/SSC Conservation Breeding Specialist Group: Apple Valley, MN (1995): pp 37-44.

South China Tiger Studbook Analysis & Masterplan, November, 1995

Armstrong, D. Physical and medical evaluation report. In Indochinese Tiger Masterplan for Thailand, Minnesota Zoo: Apple Valley, MN (1995): pp 27-28.

Shiewe, M., Loskutoff, N., Durrant, B., Johnston, L., Armstrong, D. and Simmons, L. Gaur sperm cryopreservation trial: analysis of packaging type and rapid freezing method for potential field application. Theriogenology (1994) 41: p 291

Tilson, R., Brady, G., Traylor-Holzer, K. and Armstrong, D. (Editors) Management and Conservation of Captive Tigers, Minnesota Zoo: Apple Valley, MN (1994): 1-136.

Wilson, S., Armstrong, D., Simmons, L., Morris, D. and Gross, T. A clinical trial using three regimens for immobilizing gaur (Bos gaurus). Journal of Zoo and Wildlife Medicine (1993) 24(2): pp 93-101.

Sumatran Tiger Regional Captive Breeding Workshop, Taman Safari, Indonesia, November 17-19, 1992.

Armstrong, D. and Gross, T., (Editors). Proceedings of the Wild Cattle Symposium, Henry Doorly Zoo, Omaha, Nebraska, June 13-16, 1991.

Godfrey, R., Lunstra, D., French, J., Schwartz, J., Armstrong, D. and Simmons, L. Estrous synchronization in the gaur (Bos gaurus): behavior and fertility to artificial insemination after prostaglandin treatment. Zoo Biology (1991) 10: pp 35-41.

Gross, T., Tharnish, T., Patton, M., Armstrong, D. and Simmons, L. Gaur semen cryopreservation: comparison of cryodiluents and freezing procedures. In Proceedings of the Wild Cattle Symposium, Omaha, Nebraska, June 13-16, 1991. pp 17-32

Donoghue, A., Johnston, L., Seal, U., Armstrong, D., Tilson, R., Wolf, P., Petrini, K., Simmons, L., Gross, T. and Wildt, D. In-vitro fertilization and embryo development in-vitro and in-vivo in the tiger (Panthera tigris). Biology of Reproduction (1990) 43: pp 773-744.

Armstrong, D. An evaluation of carfentanil as an immobilizing agent for gaur (Bos gaurus). Proceedings of the American Association of Zoo Veterinarians Annual Conference, 1989: p 8.

Armstrong, D., Montali, R., Doster, A. and Kazacos, K. Cerebrospinal nematodiasis in macaws due to Baylisascaris procyonis. Journal of the American Association of Veterinarians (1989) 20: pp 354-359.

Doster, A., Armstrong, D. and Bargar, T. Seminoma and parathyroid adenoma in a snow leopard (Panthera uncia). Journal of Comparative Pathology (1989) 100: pp 475-480.

Hopkins, S., Armstrong, D., Hummel, S. and Junior, S. Successful cryopreservation of gaur (Bos gaurus) epididymal spermatazoa. Journal of Zoo Animal Medicine (1989) 19: pp 195-201.

Schwartz, J., French, J., Godfrey, R., Hruska, R., Simmons, L. and Armstrong, D. Estrogen, progesterone and luteinizing hormone levels in gaur (Bos gaurus) serum during the estrous cycle. Nebraska Academy of Sciences Annual Meeting, April 14-15, 1989.

Simmons, L., Armstrong, D. and Vires, C. A chute management system for gaur (Bos gaurus). Proceedings of the American Association of Zoological Parks and Aquariums Central Regional Conference, 1989.

Simmons, L., Junior, S., Armstrong, D., Hopkins, S. and Hummel, S. Techniques for collection and cryopreservation of gaur (Bos gaurus) semen. Proceedings of the American Association of Zoological Parks and Aquariums Central Regional Conference, 1989.

Godfrey, R., Lunstra, D., Simmons, L., Armstrong, D., Schwartz, J. and French, J. Validation of a radioimmuno-assay for luteinizing hormone in gaur (Bos gaurus) serum and observations of behavior around estrus. Proceedings for the Fifth World conference on Breeding Endangered Species in Captivity (1988).

Armstrong, D., Montali, R., Kazacos, K. and Doster, A. Cerebrospinal nematodiasis in blue and gold macaws and scarlet macaws associated with Baylisascaris procyonis. Proceedings of the First International Conference on Zoological and Avian Medicine (1987): pp 489-490.

Seal, U., Armstrong, D. and Simmons, L. Yohimbine hydrochloride reversal of ketamine hydrochloride and xylazine hydrochloride immobilization of Bengal tigers and effects on hematology and serum chemistries. Journal of Wildlife Diseases (1987) 23(2): pp 296-300.

Research

Amur Leopards: Amur leopards are extraordinarily endangered in the wild. This project will help to assess the health and well being of the remaining population.

Bamboo Shark Study: Meningitis has caused deaths in several shark species. There is little information on antimicrobial therapy in these animals. This pharmacokinetic study evaluated the absorption of intramuscular injections of florfenicol and its potential application for treatment of bacterial meningitis in shark species.

Callitrichid Colon Biopsy: Colitis is a major cause of poor health and early death in captive New World primates, especially tamarins and marmosets. Mucosal biopsies of the colon have been used in studies to determine the progress of this disease and the response to therapeutic interventions. This study evaluated the callitrichid population at Omaha's Henry Doorly Zoo and Aquarium for the prevalence of this problem.

Gaur Anesthesia Trial: This investigation will help determine effective and safe ways to immobilize gaur in zoos and in the wild. Carfentanil is being compared to the newer opiod, thiafentanil. Parameters being evaluated include quality of anesthesia, cardiac values, oxygenation, circulatory pressures and recovery.

Gorilla Thyroid Project: Due to suspected background irradiation, the incidence of thyroid nodules and carcinomas is increasing in the human population. If irradiation is the cause then great apes may have a similar frequency of this disease. If the rise is due to specific human factors such as diet then the incidence in gorillas may be low. This study will help to develop a methodology for thyroid ultrasound evaluation in gorillas, will help to establish a database of thyroid health in the population and may provide answers to the health of the human population as well.

Great Ape DNA Study: Just like human beings, animals have different blood types. Knowing blood types is important when and if it is ever necessary to do a blood transfusion. Blood samples are taken opportunistically to determine blood types for great apes (including the gorilla and the orangutan) in the Species Survival Plan (SSP) population.

Lion TB Study: Bovine tuberculosis has caused a significant disease epidemic in wildlife in South Africa. It is the suspected cause of the decline in the adult lion population in Kruger National Park. Successful vaccination may a useful tool for the management of bovine tuberculosis in these lions. This project will help to determine the efficacy of a new vaccine in this species.

Tiger Calicivirus Vaccine Trial: Calicivirus causes an upper respiratory disease characterized by discharge from the nose and eyes as well as excessive salivation and oral ulcers. It has proven to be fatal in some tiger cubs. This trial will help to determine the probable efficacy of a calicivirus vaccine in tigers. Pre- and post- vaccination tigers will be measured.

Feline Hearing Study: This study will assess the value of noninvasive techniques for evaluating feline hearing using auditory evoked brainstem responses and otoacoustic emissions. The value of the study, from a conservation point of view, is that if we can identify what these cats hear, and how they might communicate, we may be able to assess how encroachment of humans and noise may affect the wild cats.

Training

Externship Program: Omaha's Henry Doorly Zoo and Aquarium's Veterinary Externship Program is designed to familiarize 4th year veterinary students, from accredited institutions, with a veterinary program in a zoological setting. Under the direct supervision of the veterinarians, students have the opportunity to utilize their medical knowledge and skills in the diagnosis and care of the exotic and wildlife species included in the collection at Omaha's Henry Doorly Zoo and Aquarium and the Wildlife Safari Park.

Internship Program: Omaha's Henry Doorly Zoo and Aquarium's Veterinary Internship is a one-year post DVM training program designed to provide broad exposure to both the medical and surgical aspects of zoological medicine. The primary purpose of this internship is to encourage the participant to apply basic skills and knowledge acquired in veterinary school and clinical practice to the health care and case management of a zoological collection. In addition to clinical medicine, this position provides interaction and opportunities in herd health management and joint research with the reproductive physiology, genetics and nutrition departments as well as other zoological institutions.

Technology Transfer: Conservation medicine at Omaha's Henry Doorly Zoo and Aquarium also involves individual programs that provide the opportunity for veterinary and graduate students from all over the United States and the rest of the world with extensive training in zoo medicine and special interests such as anesthesia and pharmacology. Training programs are also carried out overseas in conjunction with conservation projects in order to transfer specific skills and technology to colleagues in those countries. This enhances their ability to carry out their own conservation programs.