Hooo-Hooo Hooo-Hooo Volume 11 Nr 4 - Page 12

WildLife Group of the SAVA

Investigation of a suspected anthrax case in a Greater Kudu cow :

How to go About it to Improve the Potential for a Diagnosis

By : Dr Luca Mendes ( BVSc , MVetSci Cons . Med .)
Case Summary
A Greater Kudu ( Tragelaphus strepsiceros ) cow was found dead at a private game ranch in the Makana District of the Eastern Cape . The animal had been seen the day before with no obvious abnormality . An initial inspection of the carcass revealed a moderate haemorrhagic discharge from her nostrils and anus . Based on the ecology and epidemiology of the disease in Southern Africa ( Bengis , 2013 ), Anthrax ( Bacillus anthracis ) was initially suspected as the aetiological agent . On-site peripheral blood smears stained using Diff-Quick ( Kyron Laboratories , South Africa ) revealed highly suspicious , short chains of large , anthrax-like bacilli . However , further blood smears stained using polychrome methylene blue ruled out anthrax . A full post mortem was subsequently performed , which revealed a severe , generalised necro-haemorrhagic syndrome . Although further sample results were inconclusive , histopathology suggested a clostridial infection . The carcass was safely disposed of by incineration and there were no further mortalities of kudu on the ranch .
Background Information
Anthrax Ecology Anthrax is an infectious disease of wild and domestic animals and humans , caused by a Gram positive , nonmotile , endospore forming bacterium . A combination of exotoxins causes widespread damage to the reticulo-endothelial system and vasculature , resulting in varying degrees of haemorrhage and oedema and ultimately death . Ruminants and hind gut fermenters are most susceptible ( Bengis , 2013 ). In southern Africa , kudu play an important role in the ecology and epidemiology of anthrax ( Bengis , 2013 ; Clegg et al ., 2007 ; de Vos , 1990 ; Braak & de Vos , 1990 ).
Kudu Cow History Four weeks prior to death , the cow had been moved over 1800 km from Thabazimbi , in the north of South Africa , to the ranch . The relocation saw the animal being moved from a ranch in a savannah ecosystem to the arid sub-tropical thicket of the Eastern Cape .
Prior to death , this cow had appeared to adapt to the new surroundings and had been frequently observed eating browse and supplementary feed . She also had no vaccination history .
Investigation of the Carcass
Initial Assessment Prior to handling the carcass , basic protective clothing ( overalls and gum boots ) and disposable latex gloves were put on .
Mild to moderate haemorrhagic discharge was noted from her nostrils and anus while signs of paddling motions were observed in the sand . She was in average body condition ( score : 2.5 out of 5 ), with an expected level of external parasites for the region ( predominantly Amblyomma and Rhipicephalus spp . ticks ).
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WildLife Group of the SAVA Investigation of a suspected anthrax case in a Greater Kudu cow: How to go About it to Improve the Potential for a Diagnosis By: Dr Luca Mendes (BVSc, MVetSci Cons. Med.) Case Summary A Greater Kudu (Tragelaphus strepsiceros) cow was found dead at a private game ranch in the Makana District of the Eastern Cape. The animal had been seen the day before with no obvious abnormality. An initial inspection of the carcass revealed a moderate haemorrhagic discharge from her nostrils and anus. Based on the ecology and epidemiology of the disease in Southern Africa (Bengis, 2013), Anthrax (Bacillus anthracis) was initially suspected as the aetiological agent. On-site peripheral blood smears stained using Diff-Quick (Kyron Laboratories, South Africa) revealed highly suspicious, short chains of large, anthrax-like bacilli. However, further blood smears stained using polychrome methylene blue ruled out anthrax. A full post mortem was subsequently performed, which revealed a severe, generalised necro-haemorrhagic syndrome. Although further sample results were inconclusive, histopathology suggested a clostridial infection. The carcass was safely disposed of by incineration and there were no further mortalities of kudu on the ranch. Background Information Anthrax Ecology Anthrax is an infectious disease of wild and domestic animals and humans, caused by a Gram positive, non- motile, endospore forming bacterium. A combination of exotoxins causes widespread damage to the reticulo-endothelial system and vasculature, resulting in varying degrees of haemorrhage and oedema and 12 ultimately death. Ruminants and hind gut fermenters are most susceptible (Bengis, 2013). In southern Africa, kudu play an important role in the ecology and epidemiology of anthrax (Bengis, 2013; Clegg et al., 2007; de Vos, 1990; Braak & de Vos, 1990). Kudu Cow History Four weeks prior to death, the cow had been moved over 1800 km from Thabazimbi, in the north of South Africa, to the ranch. The relocation saw the animal being moved from a ranch in a savannah ecosystem to the arid sub-tropical thicket of the Eastern Cape. Prior to death, this cow had appeared to adapt to the new surroundings and had been frequentl 䁽‰Ν•ΙΩ•)•…Ρ₯Ήœ‰Ι½έΝ”…ΉΝΥΑΑ±•΅•ΉΡ…Ι䁙••ΈM‘”…±ΝΌ‘…)ΉΌΩ…₯Ή…Ρ₯½Έ‘₯ΝΡ½ΙδΈ)%ΉΩ•ΝΡ₯…Ρ₯½Έ½˜Ρ‘” …ɍ…ΝΜ)%Ή₯Ρ₯…°ΝΝ•ΝΝ΅•ΉΠ)AΙ₯½ΘΡΌ‘…Ή‘±₯ΉœΡ‘”…ɍ…ΝΜ°‰…Ν₯ŒΑΙ½Ρ•Ρ₯Ω”±½Ρ‘₯Ήœ(‘½Ω•Ι…±±Μ…ΉΥ΄‰½½ΡΜ€…Ή‘₯ΝΑ½Ν…‰±”±…Ρ•ΰ±½Ω•Μ)έ•Ι”ΑΥЁ½ΈΈ)5₯±ΡΌ΅½‘•Ι…Ρ”‘…•΅½ΙΙ‘…₯Œ‘₯͍‘…ɝ”έ…́Ή½Ρ•)™Ι½΄‘•ΘΉ½ΝΡΙ₯±Μ…Ή…ΉΎݑ₯±”Ν₯ΉΜ½˜Α…‘‘±₯Ήœ)΅½Ρ₯½ΉΜέ•Ι”½‰Ν•ΙΩ•₯ΈΡ‘”Ν…ΉΈM‘”έ…́₯Έ)…Ω•Ι…”‰½‘䁍½Ή‘₯Ρ₯½Έ€‘͍½Ι”θ€ΘΈΤ½ΥЁ½˜€Τ€°έ₯Ρ …Έ)•αΑ•Ρ•±•Ω•°½˜•αΡ•ΙΉ…°Α…Ι…Ν₯ѕ́™½ΘΡ‘”Ι•₯½Έ(‘ΑΙ•‘½΅₯Ή…ΉΡ±δ΅‰±ε½΅΅„…ΉI‘₯Α₯•Α‘…±ΎΝΑΐΈ)Ρ₯­Μ€