Redgut (rooiderm) is a disease seen in feedlot cattle, characterized mostly, by sudden death and pronounced dark red small intestines seen at the necropsy (refer to figure1).
The condition is referred to by many names, such as Jejunal Haemorrhage Syndrome, or Haemorrhagic Bowel Syndrome of Cattle, but most commonly referred to in South Africa as Redgut/Rooiderm.
The scientific name however is Clostridium Enterotoxaemia, referring to the offending agent and its mechanism of action (destruction?) inside the animal. Redgut is a sequela of acidosis.
Although it is important to note that not all animals that died from acidosis will have redgut, all animals that contract redgut will have a degree of acidosis.
The exact mechanism of the disease is uncertain, but seems to be connected to an overgrowth of Clostridium perfringes Type A.
Once an animal has acidosis, and the acidic content from the rumen reaches the abomasum and small intestines, it triggers an overgrowth of Clostridium perfringes Type A (a normal commensal bacterium in the bovine intestinal tract). These bacteria then release a toxin (enterotoxin), that severely damages the intestinal tract, causing excessive bleeding, cell death and sloughing of the tissue (see figure2).
The damaged intestinal wall leads to the loss of electrolytes and the absorption of the offending toxin into the bloodstream. This induces toxic shock and severe metabolic disturbances that leads to death.
There have been attempts to treat affected animals, with fluid-and electrolyte therapy, activated charcoal, and even surgery, all with very little success.
In a feedlot it is practical to assume that an animal that develops redgut will die.
So if we cannot treat it, then we must prevent it right? There was earlier mention in this article that redgut follows acidosis, and consequently preventing acidosis, or a drop in rumen pH, is key to preventing sudden deaths from redgut.
Acidosis is prevented by good feed- and bunk management. Easy right? Right…anybody running a feedlot knows the challenges that goes along with feed management and bunk management, but with an adequately formulated ration, proper adaption to rations, along with diligent bunk management, redgut incidents can be kept to a minimum.
As another preventative measure, there are some Clostridial vaccines available that includes a Clostridium perfringes Type A toxoid, to stimulate immunity against the abovementioned toxins in the vaccinated animal.
Although vaccination may be of value, it is very important to note that it cannot replace proper feed-and bunk management practices. It can be argued that redgut is primarily a digestive disease, i.e. although caused by bacterial toxins; the initiating factor is a digestive disturbance.
(Dr S Froneman)