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Don’t overuse antibiotics in livestock

Cattle sometimes heal themselves, but get veterinary advice

Ranchers often wonder which antibiotics they should have on hand for calving. They like to be prepared, in case a calf becomes ill, a cow needs treatment after a difficult birth, or develops mastitis or some other infection.

Dr. David Smith of Mississippi State University says cattlemen probably need to use fewer antibiotics than they have traditionally. Knowledge about antibiotic use has improved, and perspectives have changed.

“For instance, 20 years ago we might have heavily relied upon antibiotics to treat uterine infections,” says Smith. “But today we would not give a cow antibiotics unless she is clinically ill — with a fever and enough clinical signs that suggest there is a need.”

Just as in human medicine, veterinary practitioners recognize some infections don’t need treatment. The body’s immune system can usually take care of these infections, sometimes better than we can with medical intervention.

“Children with ear infections often don’t need treatment, nor do cats with urinary tract infections,” says Smith. “In most cows a uterine discharge is normal, and most uterine infections will clear up on their own, without antibiotics — most of the time. Putting antibiotics into the uterus usually does more harm than good.

“If a producer is having problems with a uterus infections (more than just a sporadic case over the years) it’s wise to have a veterinarian help figure out why this is happening. It shouldn’t be happening, so if you need to use antibiotics for uterus infections because you have a seriously sick cow, we need to find the reason and solve that problem. That would be more important than the choice of drugs.”

Smith notes there is a difference between over-the-counter medications and prescription medications. In treating a serious uterine infection, producers might have better success with a prescription medication — which means a veterinarian should be involved anyway.

Similarly, producers need to evaluate antibiotic use in calves. “Many pathogens that cause diarrhea in young calves are viruses or protozoa and don’t respond to antibiotics,” says Smith. They’d be commonly used when calves become septic or develop a secondary bacterial infection, and your veterinarian could advise you on that.

Makes scours worse

“Often what happens when we use antibiotics on scouring calves is that we make it worse,” says Smith. “The normal flora in the gut is already disrupted by whatever is causing the diarrhea, and then we disrupt it more by wiping out more of the good bacteria with the antibiotics.”

It may result in taking longer to fully recover, or the calf ending up with a fungal infection, which is worse than the original infection.

“When we do necropsies on calves that have died from scours, what we often find are fungal infections that we probably made worse, or we set up the conditions for those fungal infections because we used antibiotics,” says Smith. “Adequate fluid therapy is more important, for most cases of scours, than antibiotics.”

There are exceptions, such as a septic condition, an intestinal e-coli infection or toxic clostridial infection that all may require antibiotics. “These cases are not as common, however,” says Smith. “If you are having a lot of calves with septicemia you need to figure out what is causing it. This is another reason to have a veterinarian involved,” says Smith.

When choosing antibiotics, don’t guess. Consult a veterinarian to prescribe the most effective drug for each case. “With septic calves that really do need the antibiotic, there should be careful selection, and the choice is likely to be prescription medications,” says Smith.

In dealing with infections that might occur during calving season, the rancher should be prepared to handle the cattle in ways that prevent problems. The calving environment is very important.

“Most problems at calving are due to a difficult delivery, injury to the cow or calf from an unsafe environment, or infectious diseases,” says Smith. Delivery problems are usually related to genetics or poor nutrition. Environmental injuries may be due to weather, predators, overcrowding, or the geography.

“To prevent infections, ranchers should provide a clean, dry, comfortable place for calving,” says Smith. “If you have to assist with a birth, take the time to be clean, wash your arms with soap and water. Also wash the cow with soap and water and use lots of lubricant. We can do a lot to prevent infections just by sanitation.”

In the event of a scours outbreaks, steps should be taken to improve environmental conditions, and perhaps use pre-calving vaccines. Prevention is the key. And your veterinarian can give good advice on protocols and treatment if needed.

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