Important diseases in sheep in South Africa

In this first part of a series, we look at the some viral, bacterial and fungal diseases that can cause significant economic losses for sheep and wool farmers in South Africa.

- Janine Ryan

Sheep are vulnerable to a number of diseases, some of which are controlled diseases in South Africa. They can negatively affect carcass and wool quality, and subsequently farmers’ profitability.

PULPY KIDNEY DISEASE

Pulpy kidney disease is caused by the bacterium Clostridium perfringens (type D), which occurs naturally in the guts of sheep and goats. As described by Drs Gareth Bath and Jan de Wet in their book Sheep and Goat Diseases, the disease is known as ‘overeating disease’, as it often occurs when animals experience a sudden improvement in their diets and gorge themselves.

“When the [animal’s] digestion is disturbed, the bacteria multiply rapidly and produce large quantities of a poison that is absorbed into the bloodstream and causes acute death,” Bath and De Wet write.

When does it occur?

Pulpy kidney most commonly occurs when animals are moved from a camp with minimal grazing to another one with ample, improved grazing. It can also happen when sheep are moved from veld to pasture such as lucerne; when they’re moved to feedlots; when their diet is improved without allowing them time to acclimatise to the enhanced diet; and through the use of certain remedies, such as dewormers, which may cause the animal to consume more food.

Signs and symptoms