Posted by Dr. Steve Dudley on June 16 2005 09:52
Beef Newsletter 2nd Quarter 2005
What causes calf scours?
As new calves arrive, so does the threat of the common condition known as "calf scours". Infectious agents such as viruses, bacteria, and protozoa can cause this condition. These agents have the common property of causing loss of water and electrolytes from the calf's body through the intestine. This causes potentially life-threatening dehydration and electrolyte imbalances that can result in death. The main infectious organisms that can cause diarrhea in beef or dairy calves are: Rota virus, Corona virus, Cryptosporidium parvum, E. coli, Salmonella, and Clostridium perfringens types A, B and C.
When should I treat the calf?
Calves running around the pasture with their tails in the air, bucking and kicking with yellow or white diarrhea may not need treatment, but must be watched closely, as dehydration can occur quickly. The main indications for treatment are:
- General depression
- Loss of appetite (gaunt calves)
- Dehydration
- Abnormal body temperature (normal rectal temperature = 100.5-102.5)
In the early stages of diarrhea, the calf appears bright, eats and drinks well, and the only evidence of disease is an increase in the volume and water content of the feces. The stool volume and fluid content increase as the condition progresses and the material being passed becomes a clear liquid. At this stage the base of the tail and hindquarters simply appear wet. The loss of body fluid and electrolytes through the passage of large volumes of watery feces causes signs of dehydration in other parts of the body as well. The hair coat and skin become dry and scruffy, the abdomen gaunt, the eyes, nose and mouth become dry and the skin feels leathery to the touch. As the calf's condition deteriorates further, the eyes sink into the sockets, the nose becomes dry, the skin feels very leathery and the skin will stay "tented" (raised) after it is pinched. The animals are usually quite weak at this time and many are unable to stand or lift their heads.
It is important to note that calves with diarrhea often have what appears to be an insatiable thirst. If given warm electrolyte solutions or even very weak salt solutions, the calf will usually drink very large quantities. This appears to be an attempt on the part of the animal to compensate for the water and electrolyte losses that have occurred as a result of the scouring.