Steve Wikse, professor of large animal clinical sciences, College of Veterinary Medicine at Texas A&M University, answers this month's beef cattle health question.
Q - This colder weather has resulted in a few cases of scours in my late-fall calves. What is the best way to treat calf scours?
A - Well, I'd like to start with an explanation of what causes diarrhea in calves and the physiologic changes that occur. This will help you understand what you are treating. Diarrhea in calves is caused by a complex combination of environmental, host and infectious agent factors. Infectious agents by themselves rarely cause diarrhea.
Environmental factors include adverse weather, which impairs the immune system of calves and can cause a buildup of infectious agents that cause diarrhea. For example, crowded conditions in the calving pasture, plus poor drainage, can result in a buildup of infectious agents that can overwhelm a calf's immune system.
Host factors affecting a calf's resistance to infectious agents that cause scours include inadequate ingestion of colostrum and nutritional deficiencies. Calves that do not get adequate amounts of antibody from their dam's colostrum are sitting ducks for infections.
Many infectious agents are associated with calf scours. The most common are the bacterium E. coli, rotavirus and coronavirus, and the protozoan cryptosporidia. Bovine viral diarrhea virus and the bacteria Salmonella spp. and Clostridium perfringenes are occasionally involved. Calves with diarrhea are usually infected with two or three agents simultaneously.
Calf scours usually affect calves the first three weeks of life. They develop a profuse diarrhea that depletes them of water. Calves that are dehydrated have sunken eyes, a dry mouth and stiff skin. Electrolytes are also lost in the diarrhea, including bicarbonate, which is needed for the normal balance of acid and base in the body. The acidosis that results combined with dehydration causes calves to crash. In other words, they become very weak, unable to stand, lose their suckle reflex and go into a coma. The main causes of death in diarrheic calves are the physiologic changes caused by dehydration and acidosis.
Diarrhea in calves is treated by a combination of fluid therapy, nursing care and antibiotics.
Fluid therapy is the foundation of treatment because it corrects dehydration and acidosis. Nursing care consists of keeping severely ill calves in a warm, dry environment. Antibiotics should be given to some - but not all - calves with diarrhea. Calves with different degrees of illness should be treated accordingly. I will describe my suggested treatments for the varying degrees of severity of scours in calves.
• Calf is standing and alert.
This calf just needs one to two quarts of an oral electrolyte solution two times a day administered by nursing the calf with an Alber's bottle, if possible. Otherwise, use an esophageal feeder to administer the fluids. Meanwhile, let the calf remain with the cow. Continue treatment for one to three days until the calf is urinating and the stool is firming up.
Packets of commercial electrolyte mixes can be purchased from your veterinarian or from a local cooperative. You also can make up a homemade calf scours electrolyte mixture which includes the following:
1 package jam and jelly pectin (two ounces)
1 tablespoon lite salt
1 tablespoon baking soda
Make up to two quarts of mixture with water.
• Calf is lying down and weak, but can stand if encouraged.
A decision must be made on a down calf. It should be taken to the veterinary clinic for advanced care under two circumstances:
• If its legs and mouth are cold, the calf is in shock and must be taken to the veterinary clinic for intravenous fluids.
• If the down calf is not dehydrated and has a fever, it likely has a systemic bacterial infection and will need critical veterinary care to survive. These calves usually have swollen navels and joints.
If the calf has a warm mouth and legs, the following treatment can be attempted at home:
• Continue with fluids, but administer fluids three times a day.
Add antibiotic injections. Systemic antibiotics are superior to oral antibiotics. Some oral antibiotics, including neomycin and tetracycline, cause a malabsorption syndrome resulting in diarrhea. Naxcel (ceftiofur - Pfizer Animal Health) or Nuflor (florfenicol - Schering-Plough) are two antibiotics to consider when treating severe cases of calf scours. They are only available from your veterinarian, and use of these antibiotics should be used according to a veterinarian's instructions. Antibiotic treatment should continue for five to seven days.
• Add good nursing care. Place these calves in a warm, well-bedded environment. Warm them up with hot water bottles or a heat lamp.
• Calf is down and unable to rise.
This calf is in critical condition and must be taken to the veterinary clinic for hospitalization and intensive care.
In this column I've given you an overview of how calves with diarrhea can be successfully treated. However, there is not room in this column for details on fine-tuning a treatment. But one practice worth learning is knowing how to pass an esophageal feeder into a calf. This will enable you to successfully treat a calf's diarrhea, along with administering colostrum to newborns that are too weak to nurse. It's a treatment that can surely come in handy out on the ranch. If you do not know how to pass an esophageal feeder, ask your veterinarian to teach you.
In fact, a close relationship with your veterinarian will ensure that you are up to date on all the latest effective ways to treat and prevent disease in your herd. That adds up to more profit.
• E-mail vet questions to beverly.moseley@theeagle.com.
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