Overeating of milk, grain, fruit, or any other carbohydrate-rich substance can cause diarrhea in individual animals of any age. As mentioned, intestinal bacteria can cause fermentation of intestinal contents and the subsequent osmotic pressure draws fluid into the bowel; severe diarrhea can result. Non-specific treatment of these nutritional causes of scours includes removal or discontinuation of the causative substance, feeding a bland diet such as grass hay or straw, giving electrolytes if dehydration becomes severe, and administering medications such as Pepto-Bismol® that normalize intestinal contraction rates. Oral antibiotics are rarely indicated, recommended or necessary.
“White milk scours” or nutritional scours is a syndrome sometimes seen when calves and cows are re-united after being separated for several hours. Examples of this scenario include sorting, pregnancy checking, vaccinating, or when a pair becomes separated on the range. After the pairs are reunited, the hungry calves nurse heavily; the consumption of a large meal of milk overwhelms the capacity of the calf’s stomach and undigested milk passes directly through the intestinal tract and causes white scours. Affected animals usually have no signs of illness and nutritional scours resolves itself within a day or two. Some animals may show mild colic, stop nursing and become depressed. Treatment with electrolytes and Pepto-Bismol® as mentioned above should suffice.
A few other minor causes of scours include various poisonous plants (elderberry, azalea, etc.), arsenic poisoning, Astrovirus infection, Enteroviruses, cobalt deficiency, zinc deficiency, selenium deficiency, copper deficiency, molybdenum toxicity, mycotoxins, organophosphate poisoning, water toxicity, water deficiency, Chlamydia, Clostridium haemolyticum (“red water disease” or bacillary hemoglobinuria) Shigella, and Yersinia enterocolitica.
Source: Dr. Susan R. Kerr, DVM, PhD, WSU Klickitat County Extension Director