Oral or IV

When a scouring calf needs rehydration, should it be provided orally or intravenously?

by Heather Thomas

When treating scours, producers often wonder whether the sick calf needs fluids and, if so, should it be given fluids orally or intravenously (by IV)? Steve Hendrick, University of Saskatchewan, says if the scouring calf is easy to catch, it needs fluid. Oral fluids, given often enough, can reverse dehydration unless the calf has gone past the point where it can absorb fluids through the gut.

Once the calf becomes too dehydrated, the gut shuts down and oral fluids can't be absorbed. A good rule of thumb, he says, is if the calf can still stand and walk, give it oral fluids. If it is too weak to get up, has a poor suckle reflex (no longer tries to suck your finger when you put it in its mouth) and can't raise its head, the calf needs an IV.

"At that point he is going into shock," Hendrick explains. "He's lost so much body fluid that blood volume is low. The gut can't absorb fluids because the body is trying to get blood to vital organs instead. You won't be able to save the calf without an IV."

Signs of serious dehydration include lethargy (dull instead of lively) and weakness, sunken eyes and cold extremities.

"If the calf is gaunt and the eyes are sunken, he's probably already 7% to 10% dehydrated, and may need IV fluids. If the calf is not responsive, becoming more weak and cold, he definitely needs an IV," says Hendrick.

"One way to tell whether the calf can utilize oral fluids or needs an IV is to assess the suckle reflex. If you are trying to tube-feed through the mouth and the calf's tongue is still active, he probably can utilize oral fluids." But if the calf is depressed and dull and doesn't have much tongue response or resistance, it needs an IV.

To prevent/combat dehydration, the calf should have an adequate amount of oral fluid, given often.

"I generally don't give a calf more than 2 liters at a time," Hendrick says. "It's more work to tube him several times a day and clean the tube, but it will help him recover quicker." And that means fewer days of treatment in the long run.

If a calf is severely dehydrated, the more often you can give fluids, the more chance you'll save it, especially a young calf. Hendrick recommends giving fluids every 8 hours, but in calves less than a week of age, give fluids every 4-6 hours.

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