Wildlife Disease

Dr J A Pretorius (BVSc, MMedVet (Fer)

This is a very broad subject and can roughly be divided in two parts: healthcare of individual animals and healthcare of populations, whether on a farm or a country’s population as a whole.

If in doubt, or for more information, please contact your nearest wildlife veterinarian

Healthcare of individual animals

The care of orphaned or injured wildlife is very specialized and should not be attempted by any layperson. Hand-reared wildlife often become very aggressive and several people have been injured or killed by “pet” wildlife. There is also legislation against keeping wildlife as pets in South Africa and a permit must be issued by Nature Conservation of the relevant province. They are however very strict on this and animals should rather be referred to registered rehabilitation facilities for wildlife. The aim of these facilities is to reintroduce these animals back into the wild if possible. If a game farm owner however have the relevant permits and wish to continue the treatment or rearing of an animal, it is advised to consult with a veterinarian with wildlife experience as each species has very specific needs.
Treating wild animals often is problematic especially in the case of ungulates. Keeping them in holding facilities is very stressful and often the animals die rather of the associated stress than the original problem, injury or disease. Animals in holding facilities for quarantine purposes or before an auction, need special attention and again it is advised to have an experienced veterinarian involved with the whole process. Before animals are off-loaded into the pens, they need to be treated for internal and external parasites, as well as long-acting antibiotics and tranquillisers. Without these treatments animals will lose condition and easily become ill. Pneumonia is often a problem in dusty pens.

Healthcare of populations

Wildlife is often reservoir hosts of diseases that can affect domestic animals. The disease can be fatal or have serious economic effects for the farmer and the country as a whole. This resulted that several diseases carried by wildlife has been classed as either controlled or notifiable diseases in South Africa. Certain diseases can spread from domestic animals to wildlife and also need to be controlled. An example is buffalo that before they can be moved from a farm or reserve, they need to be tested for foot-and-mouth disease (FMD), corridor disease, brucellosis and tuberculosis. Buffalo are reservoir hosts for FMD and corridor disease, whereas they can be infected with brucellosis and tuberculosis, transmitted from cattle. Warthogs are the reservoir hosts for African swine fever (ASF) and this is also a controlled disease which prevents the movement of any warthog or warthog product without veterinary permits and not at all from ASF areas to the ASF-free areas. Zebra, for example, can carry African horse sickness (AHS) virus and cannot be moved to the Western Cape during the warmer months of the year. This is a controlled AHS-free area. AHS is a controlled disease in South Africa and if a horse dies of AHS the owner or the veterinarian involved must notify the relevant state veterinarian. Rift valley fever can affect buffalo the same as cattle and buffalo can during an outbreak be vaccinated with the killed vaccine.

Other diseases that are not economically as important, or don’t have zoonotic potential, are classified as notifiable diseases. Black and blue wildebeest are the reservoir hosts for malignant catarrhal fever virus that causes malignant catarrhal fever (MCF) in cattle. It is also known in Afrikaans as “Snotsiekte”. This disease is fatal in cattle and the disease has just become a notifiable disease in South Africa. Sheep is the reservoir host of a similar virus that causes the same disease in cattle. This makes control of the disease very problematic.
More information on the controlled and notifiable disease can be found on the website: http://www.daff.gov.za/

Heartwater is a tick-borne disease of mainly livestock, but also of some wild ruminants caused by the rickettsia Ehrlichia ruminantium (previously known as Cowdria ruminantium). E. ruminantium is transmitted by ticks of the genus Amblyomma. Mainly species historically from areas outside the Amblyomma distribution, and thus from areas outside the heartwater area, seem to be affected when introduced into an endemic area. In southern Africa antelope species such as the springbok (Antidorcas marsupialis), eland (Taurotragus oryx), black wildebeest (Connochaetus gnou), sitatunga (Tragelaphus spekei) and lechwe (Kobus leche kafuensis) are reported to have developed clinical disease. In blesbok (Damaliscus dorcas phillipsi) clinical disease has been reported but is very rarely seen under natural conditions. The black wildebeest, blesbok and eland as well as giraffe (Giraffa camelopardalis) can be affected sub-clinically.