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No magic cures for scours |   Back to Vet Advice

Dr. Valerie Smid

In the springtime, I can safely say that one of the most frequent questions asked is "What is the best drug to treat scours in my calves?" Oh if only the answer was as easy as marching over to the shelf and handing you the bottle of Magic Scour Cure. Unfortunately, no such thing exists.

There are a number of preventative strategies that can be used but sometimes, despite all our best efforts, we find ourselves with cases of diarrhea in calves that need to be dealt with on an individual basis. What follows are the questions I am most commonly asked regarding treatment of calves with diarrhea.

When do I need to bring a calf to the veterinarian?

My rule of thumb, if you're already asking yourself that question, is err on the side of caution and have it seen, especially, if you've never really had to treat one of these cases before. Your veterinarian can show you what to check (temperature, the navel, joints and dehydration), and how to tube feed without getting fluid into the lungs.

Some signs that you can use that indicate you ought to get the calf to the vet sooner, rather than later, for intravenous fluids and possibly other therapy include:

• Calf is flat out and not responding to being stimulated.
• Eyes are quite sunken into the head and calf is not interested in nursing at all.
• He doesn't appear dehydrated (sunken eyes, skin on neck stays tented up when pinched) but he seems quite depressed. Might be suffering from "metabolic acidosis" which is when the pH of the blood is acidic because of loss of bicarbonate in the diarrhea.

That's not an exhaustive list, but it's a place to start.

Do I really need to give electrolytes or is a shot of antibiotics enough?

I sympathize that you may have to catch them to give them oral electrolytes. But it is necessary unless the calf has only a mild case and is still nursing well enough to replace his own fluid and electrolyte losses. Otherwise, the calf becomes dehydrated, his blood electrolytes go out of balance and he loses weight. The loss of those electrolytes is what ends up killing him by causing severe neurological depression and heart arrythmias (irregular heartbeat). So we need to replace those with fluids from a bottle or tube feeder, or intravenously in more serious cases.

Are antibiotics helpful in calves with diarrhea? They don't kill viruses or parasites that may be causing the diarrhea but they do treat the overgrowth of harmful bacteria often found in the gut of these calves, and helps speed the recovery. Consult your veterinarian. In most cases it should be an injectable antibiotic/antimicrobial; the research generally doesn't support the effectiveness of the calf boluses on the market.

Which electrolyte preparation is best? How often do I need to feed it?

In general, electrolyte solutions are high energy (usually have "HE" on the label) with an additional source of glucose and/or other nutrients, or regular. A good rule of thumb is to feed high-energy formulations to calves that aren't nursing and regular solutions to those that are. Do not mix electrolytes with milk instead of water. This creates a concentrated solution that can just make the situation worse. You also want an electrolyte solution with "acetate," not "bicarbonate" as the buffering agent. Bicarbonate is thought to interfere with milk digestion. While you're at the clinic getting electrolyte solutions, make sure you have a proper tube feeder and maybe an extra one so one can be cleaned and dried while the other one is in use.

You generally need to give two litres of electrolytes (one package) every 12 hours, even more if the calf is losing a lot of fluids. Evenly space out the feedings, if possible.

Should the calves be kept off milk?

Research shows calves that continue to nurse while being treated for diarrhea lose the same or less weight than calves taken off milk. Young calves don't have a lot of fat reserves and require constant nutrition to maintain themselves and grow. That said, there are times when removing milk for 24 to 48 hours gives the gut a chance to rest and recover. But then you should make sure you feed the "HE" electrolyte and don't withhold milk beyond 48 hours.

How do I know if the treatment is working?

Here are some signs that what you're doing is no longer effective:

• A bloating belly, especially after feeding electrolytes a few times. Sometimes, the calf's condition is deteriorating enough the fluids you're feeding aren't being absorbed but just gathering in the stomach. This calf needs intravenous fluids and electrolytes (often bicarbonate intravenously).
• Swelling of the navel or joints might indicate a more serious infection in addition to the diarrhea and more aggressive therapy is needed.
• A fever despite antibiotic treatment might be caused by a secondary infection (pneumonia, peritonitis which is an infection in the belly) or something that is not responsive to the antibiotic. Don't just reach for another antibiotic before you give your vet a chance to assess the calf.
• Blood in the diarrhea: A bit of blood is not unusual but if you start to see a moderate amount along with what looks like mucous plugs, it might mean another infectious agent has entered the mix.

So, you can see that calf diarrhea is not a simple disease with a simple cure. There is no one cure-all drug, that will make it all go away or treat every case. It will take vigilance and timely treatment to have a chance of success.

-- Dr. Valerie Smid is a clinical veterinarian at the University of Manitoba and a member of the Western Canadian Association of Bovine Practitioners who co-ordinate this column. Reprinted from Canadian Cattlemen magazine, April 2008.

If you want some Vet Advice for a specific problem on your farm or ranch, send your questions to Cattlemen, The Beef Magazine, 1666 Dublin Ave., Winnipeg, Man. R3H 0H1.