Disease Management & Veterinary Interventions

Anthrax (2004)

The anthrax outbreak between August and November 2004 was particularly severe, killing almost the entire kudu population. Nyala (68%), bushbuck (48%), waterbuck (44%), roan (42%), wild dog (27%), and hippopotamus (21%) were also badly affected. A total of 906 carcasses were located and disposed of by burning or burying.

To control the spread of the disease, 20 roan, 15 black rhinos, 39 white rhinos and five hippos were vaccinated from a helicopter using drop-out darts. A further 821 buffalo, 81 waterbuck and two kudus were vaccinated by herding them into a capture boma and pole-syringing them. The aim of the vaccination was not to eliminate anthrax, but to protect the reserve’s most vulnerable and high-value populations.

To assess the effectiveness of the disposal methods, soil samples were collected at 78 sites where carcasses had been burned or buried. Anthrax bacteria were detected in only three samples, indicating that the disposal had been effective in restricting residual contamination.

Rabies (2007)

Between March and June 2007, Malilangwe’s wild dog population was decimated by rabies. Of the 75 individuals known on the reserve, only two survived. One pack (originally 21 animals) had been habituated by wildlife cinematographer Kim Wolhuter and was comfortable around his vehicle, making it possible to vaccinate and monitor 19 of the animals. The dogs were vaccinated from the vehicle using drop-out darts and given a booster seven days later; two fresh impala carcasses were used to keep them close during darting.

Dogs affected by rabies tried to feed but largely could not, appearing to have difficulty swallowing. They had the same problem when attempting to drink, and notably showed no fear of water, even bathing. Other clinical signs included biting branches, repeated rolling, running the side of the mouth along the ground as if trying to remove something, pawing at an open mouth, and non-aggressive nipping of other individuals, especially while resting. In the late stage of infection their stomachs were clearly withdrawn and they were weak and unsteady. Excessive or frothy saliva was not noted, and the dogs were not aggressive.

Despite efforts to save a core population, all but two dogs succumbed. One survivor had been vaccinated 12 days earlier when fitted with a radio collar – this early inoculation may have been the reason it survived.

Malilangwe’s wild dog population has since recovered and the reserve is now home to three established packs – one pack of 17, one of 11, and one of 7. To help guard against future outbreaks, Malilangwe now operates a vaccination programme that immunizes more than 3,000 domestic dogs in the surrounding with the 7-in-1 vaccine annually. This has proved to be an effective approach so far, and one we hope will continue to be effective moving forward.

Snare Removal

Malilangwe’s Scouts have eliminated snare poaching from within the reserve. However, wild dogs and hyenas sometimes leave the reserve – by slipping under the boom gate on the road or digging under the fence – and return carrying wire snares. When possible, these animals are immobilised, the snares removed, and their wounds treated.