Abstract

Information on the veterinary management of shoebills (Balaeniceps rex) is scarce. This is regrettable since this species has never successfully been bred in captivity and zoos depend on imports from the wild. This certainly is a sign that their captive management is not yet satisfactory. This presentation is intended to improve the available data on shoebills by summarizing physiologic data measured in clinically healthy captive shoebills and by presenting successfully used medications, thus hopefully making a contribution to an improved captive management.

The International Species Information System (ISIS) lists 18 animals that are kept in the United States of America (Cincinnati Zoo and San Diego Wild Animal Park), Japan (Ueno Zoological Gardens), and Europe (Frankfurt Zoo, Wuppertal Zoo, and Zurich Zoo).¹ A single record of egg production outside its natural habitat exists from 1994 in the Stuttgart Zoo.

Data presented originates from European Zoos that keep a total of four male and two female shoebills and of the Stuttgart Zoo, which at this time does not keep shoebills. Due to the fact that the only record of egg production originates from the Stuttgart Zoo and the important number of animals previously kept there, information from that institution has been included in this abstract.

The birds currently living in European zoos are between 4–23 years of age, and they weigh between 5–6.5 kg. All shoebills are apparently clinically healthy. Blood was repeatedly taken from a pair of shoebills at the Zurich Zoo, and values have been summarized in Table 1. Regarding hematology, it was noted that the white blood cell count including basophile count was high compared to other storks and that lymphocytes were comparatively low.^2,3 Further blood analyses will be needed to ascertain this observation and allow for interpretation. Elevated uric acid values with large standard deviation as found in the studied shoebills are consistent with carnivory.

Table 1. Average blood values of a pair of adult shoebills (Balaeniceps rex) kept at the Zurich Zoo

^aNumber of samples

Regarding blood values, it was recently published that the shoebill, which phylogenetically still is an enigma, was found to contain as its dominant biliary bile acid 16-alpha­hydroxychenodeoxycholic acid, a heretofore undescribed bile acid. A search for this novel bile acid in other Ciconiiformes showed that it constituted >92% of biliary bile acids in five of nine herons in the Ardidae, but was absent in all other families (Ciconiidae, Threskiomithidae, Scopidae, Phoenicopteridae). The presence of this biochemical trait in the shoebill and certain herons suggests that these birds are closely related.⁴ Two animals at the Zurich Zoo underwent surgical sexing under isoflurane anesthesia without apparent problems.

Veterinary problems in the study population are mainly related to the legs with mild to severe pododermatitis and hyperkeratosis. From observations in the study population, it appears that offering soft flooring is the best prophylaxis and treatment. At the Zurich Zoo, two animals developed hyperkeratosis on the tibiotarsus and tarsometatarsus. The problem resolved within 2 months under weekly treatment with an ointment that contained salicylic acid. In all institutions, superficial trauma occurred as a result of interspecific aggression. Dressing of the wounds was the method of choice and was always successful. As with other birds, shoebills are very susceptible to aspergillosis. Furthermore, four cases of arteriosclerosis have been described.⁵ Medications which repeatedly have been successfully used in shoebills in European zoos are listed in Table 2.

Table 2. Medications used successfully in shoebills (Balaeniceps rex) in European zoos

Literature Cited

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2.  Alonso, J.C., V. Huecas, J.A. Alonso, M. Abelenda, R. Munoz-Pulido and M.L. Puerta. 1991. Hematology and blood chemistry of adult white storks (Ciconia ciconia). Comp. Biochem. Physiol. 98 A: 395–397.

3.  Celdran, J., F.J. Polo, V.I. Peinado, G. Viscor and J. Palomeque. 1994. Haematology of captive herons, egrets, spoonbill, ibis and gallinule. Comp. Biochem. Physiol. 107 A: 337–341.

4.  Hagey, L.R., C.D. Schteingart, H.T. Ton-Nu and A.F. Hofmann. 2002. A novel primary bile acid in the shoebill stork and herons and its phylogenetic significance. J. Lipid Res. 43: 685–690.

5.  Heldstab, A., D. Riiedi and R. Millier. 1978. Arteriosklerose beim Schuhschnabel (Balaeniceps rex). Ver. ber. Erkrg. Zootiere. 20: 251–254.