Case report — Gevalverslag Tuberculosis in Kafue lechwe (Kobus leche kafuensis) and in a bushbuck (Tragelaphus scriptus) on a game ranch in Central Province, Zambia U Ziegera*, G S Pandeyb, N P J Kriekc and A E Cauldwella bacteriosis, 2 in Kafue lechwe and 1 in a ABSTRACT bushbuck from a private game ranch near Mycobacteriosis was diagnosed for the first time outside a national park in free-ranging Lusaka. The pathological and histological wild animals on a game ranch in Zambia. A Kafue lechwe (Kobus leche kafuensis) was found lesions were typical of tuberculosis in all 3 dead with tuberculous lesions on a ranch near Lusaka. Acid-fast bacilli were found in the cases; however, mycobacteria could only affected organs. Mycobacteria were isolated from these tissues. A bushbuck (Tragelaphus be isolated from 1 of the Kafue lechwe. scriptus) was found dead on the same ranch with multiple superficial abscesses in the neck Unfortunately, appropriate biochemical region, extensive granulomatous lesions in the lung, the bronchial and mediastinal lymph tests were not available at the time to nodes and several nodular lesions in the spleen. Few acid-fast bacilli were found in the exudate from the abscesses and lesions in the affected organs. Histologically the lesions confirm without doubt that the isolate resembled those of tuberculosis, but mycobacteria could not be isolated. In addition, 1 Kafue was M bovis. The strong suspicion, lechwe among 37 wild ungulates of 13 species shot on the ranch showed typical tuberculous however, that bovine tuberculosis is lesions in the lungs, but the diagnosis was not confirmed by bacterial isolation. The role of present in wildlife on private Zambian the Kafue lechwe as maintenance host for tuberculosis as well as in the possible spread of ranches warrants attention. The danger of this disease to other wildlife are discussed. spreading tuberculosis through wildlife Key words: bushbuck (Tragelaphus scriptus), Kafue lechwe (Kobus leche kafuensis), mycobac- translocations is emphasised. teriosis, tuberculosis, wildlife, Zambia. MATERIALS AND METHODS Zieger U, Pandey G S, Kriek N P J, Cauldwell A E Tuberculosis in Kafue lechwe (Kobus leche kafuensis) and in a bushbuck (Tragelaphus scriptus) on a game ranch in Central Animals Province, Zambia. Journal of the South African Veterinary Association (1998) 69(3): 98–101 (En.). Centre for Wildlife Management, University of Pretoria, Pretoria, 0002 South Africa. All animals came from a private game ranch (15.05 S, 28.15 E) located in the Chisamba District in the Central Province of Zambia, approximately 20 km north of INTRODUCTION endemic in African buffalo (Syncerus Lusaka. This ranch has operated commer- Tuberculosis, caused by Mycobacterium caffer) and in warthog (Phacochoerus cially as a game ranch since 1990, when bovis, has been described in a variety of aethiopicus) populations in the Queen wildlife was first introduced. Eighteen captive and free-ranging wild animals. Elizabeth National Park in Uganda9,26,27. ungulate species are present at a stocking Among the latter, self-maintaining infec- High prevalence rates of M. bovis infec- rate of approximately 1 large stock unit tions have been reported in the European tions were found in wild olive baboons per 4.7 ha16. badger (Meles meles) in the United King- (Papio cynocephalus anubis) in the Masai A male Kafue lechwe was found freshly dom; in the brush-tailed possum (Tricho- Mara Game Reserve in Kenya20. Recently, dead on the ranch in November 1996. The surus vulpecula) in New Zealand and in an outbreak of tuberculosis in a free- carcass was transported immediately to farmed fallow deer (Dama dama) as well as ranging African buffalo population and the Disease Control Laboratory of the red deer (Cervus elaphus) in several other subsequent spread of this disease to other School of Veterinary Science, University countries3,4,6,23,25. The first cases of bovine species was reported from the Kruger of Zambia, for a post mortem examination. tuberculosis in free-ranging wild animals National Park, South Africa2,12,13. This animal had been dead for presum- in South Africa were reported in 1928 in In Zambia, tuberculosis caused by ably 5–6 hours when the necropsy was greater kudu (Tragelaphus strepsiceros) and M. bovis in free-ranging wild animals has conducted. common duiker (Sylvicapra grimmia)18. been reported only in a single eland A male bushbuck (Tragelaphus scriptus) Greater kudu were later found to be (Taurotragus oryx)15 and in Kafue lechwe was found dead on the same ranch in endemically infected with M. bovis in the (Kobus leche kafuensis)5,8,15. It was suggested September 1996. A necropsy was Eastern Cape region of South Africa24. that tuberculous cattle that shared the performed immediately on site. It was Tuberculosis caused by M. bovis is grazing on the Kafue flood plains with estimated that the bushbuck had been lechwe introduced this disease to the dead for about 2–3 hours when the susceptible wildlife population8. necropsy was conducted. All organs that aCentre for Wildlife Management, University of Pretoria, In 1989 the legislation in Zambia contained lesions were cooled at 4 °C and Pretoria, 0002 South Africa. pertaining to wildlife was amended and transported to the same laboratory for bSchool of Veterinary Science, University of Zambia, many private game ranches have since diagnosis. Lusaka, Zambia. been established. Several ranches were In addition, 37 wild ungulates were shot cFaculty of Veterinary Science, University of Pretoria, stocked, amongst other species, with on the ranch between December 1995 Onderstepoort, 0110 South Africa. Kafue lechwe that had been captured on and November 1996 for venison, as *To whom correspondence should be addressed. the Kafue flood plains. This report trophies or because of injuries. These Received: February 1998. Accepted: June 1998. presents 3 cases of tuberculosis or myco- animals included 1 Burchell’s zebra 98 0038-2809 Tydskr.S.Afr.vet.Ver. (1998) 69(3): 98–101 (Equus burchellii), 2 bushpigs (Potamocho- tissue was replaced by calcified, white enlarged and up to 120 mm in diameter. erus larvatus), 11 impala (Aepyceros melam- necrotic material that was hard and Most of them were firm and contained pus), 3 tsessebe (Damaliscus lunatus gritty to cut. The testes revealed a few necrotic material while 1 contained a lunatus), 1 Lichtenstein’s hartebeest (Sig- yellowish nodules on their surface. The yellowish-white exudate. The spleen moceros lichtensteinii), 2 eland, 2 bushbuck, urinary bladder was full of turbid urine. showed disseminated miliary lesions, 4 greater kudu, 2 sable antelope (Hippotra- The visceral surface of the bladder many of which were calcified. gus niger), 6 defassa waterbuck (Kobus showed a few whitish, pinhead-sized The impression smears made from ellipsiprymnus defassa), 1 Kafue lechwe, 1 nodules. exudate obtained from the abscesses puku (Kobus vardonii) and 1 reedbuck Large numbers of acid-fast bacilli were revealed only few acid-fast bacteria. (Redunca arundinum). All carcasses were seen in the smears made from the kidneys Microscopically the lesions in the lungs, transported immediately after death to a and the urine sediment while few lymph nodes and the spleen were similar nearby abattoir. In addition to standard acid-fast bacteria were present in the in appearance. The lesions consisted of meat inspection procedures, the thoracic impression smears made from the lungs large masses of caseous necrotic material and visceral organs were examined more and the mediastinal lymph nodes. Micro- enveloped by an attenuated granuloma- thoroughly according to standard scopically the lesions were characterised tous inflammatory reaction. Scattered foci necropsy procedures. by large aggregates of epithelioid cells of calcification occurred in the necrotic and the lack of Langhan’s giant cells. Few tissue. The lesions were further charac- Gross and histopathology acid-fast bacilli were detected in the cyto- terised by the presence of numerous All observed abnormalities were plasm of epithelioid cells. The lesions neutrophils in the reaction. Few scattered, recorded while the necropsies were were typical of tuberculosis. With the acid-fast bacilli were seen in the cyto- performed. Specimens of selected organs exception of severe testicular atrophy, no plasm of Langhan’s giant cells and in the were preserved in 10 % formol saline. other lesions were seen in the testis. necrotic debris. These findings suggest a These were later routinely processed and Colonies of acid-fast bacteria were seen diagnosis of tuberculosis. stained with haematoxylin and eosin for after 5 weeks of incubation on the LJ No growth was obtained on LJ medium histological examination. Selected tissue media slants containing pyruvate inocu- during 10 weeks of incubation. sections as well as smears of exudates lated with material extracted from the were stained with the Ziehl-Neelsen stain kidneys, urine and lungs. The colonies Culled animals for the detection of acid-fast bacteria. were white and had a smooth surface. No Typical tuberculous lesions were found growth was observed on media either in 1 of the 37 animals that were shot. This Bacteriology with or without glycerine during 8 weeks was a 3-year-old Kafue lechwe, which was Specimens of affected organs were of incubation. The culture was found to culled because of a hind-leg injury collected and processed for bacterial be niacin-negative and sensitive to but appeared otherwise healthy. Several isolation and identification1.