Milk fever strikes
In 2002, I had my first
case of milk fever (hypocalcemia), my only instance in over thirty years
of sheep raising. The ewes were two to three weeks pre-partum. I had
gone out of town for a few days and asked a neighbor to feed for me.
My ewes were small to medium sized -- purebred Katahdins bred to a 3/4 Dorper
ram. They were receiving 2 lbs. of whole barley per day, plus 2 lbs.
of a mixed hay, split into two feedings. They also had free choice
access to a trace mineral mix, which they had been consuming like gang busters.
When I returned from my trip and fed my sheep that evening, they didn't go after the feed like they normally had. One ewe was off feed completely. I checked with my neighbor and she said everything had been fine while I was gone. I went to bed, hoping that everything would be back to normal the next morning.
But, the next morning, I found another ewe down, splayed out, with her head cocked back. Her temperature was normal and she was slightly bloated. There wasn't much life left in her. The ewe that had not eaten the night before was sluggish and still not eating. She had a stilted gait.
When ewes go off feed or down during late pregnancy, my first thought is pregnancy toxemia (ketosis), so I went ahead and gave the mobile ewe a dose of propylene glycol. The downed ewe was in no shape to receive oral therapy, plus I had serious doubts about it being ketosis since the ewes were consuming a ration that was more than adequate in energy.
Thus, my next thought was milk fever, another likely problem during late pregnancy. I knew that the ewes were receiving very little calcium through the barley and with the hay not containing a lot of clover and being of poor quality (stemmy), not much calcium was being provided there either. I zeroed in on milk fever. Obviously, these two ewes had not been consuming adequate amounts of the free choice mineral, particularly with respect to their increasing needs for calcium during late gestation.
I administered calcium gluconate under the skin and while this might have been adequate for the one ewe, it would not get into the bloodstream quick enough for the downed ewe. It was a race against the clock to save her. It had been awhile (since graduate school ) since I had bled ewes via the jugular vein, so I elected to call a vet. I am new to the area and I thought this would also be a good opportunity to establish a relationship with a local veterinarian. He arrived within two hours and administered calcium and dextrose via jugular IV to both ewes.
After receiving calcium intravenously, the down ewe lifted her head and began to show interest in her surroundings. She changed positions for the next several hours and began to nibble on grain and hay that evening. Over the next four to five days her appetite remained very poor, particularly with respect to the grain, so I continued to administer calcium subcutaneously.
I dosed her with propylene glycol twice a day and gave her an injection of vitamin B-complex to stimulate her appetite. She is now fully recovered from her near-death experience. The other ewe received an additional oral dose of calcium and was back to normal within a day. I dosed a few other ewes that were looking dopey with oral calcium.
This mini-outbreak of milk fever gave me cause to re-evaluate my ration and make adjustments to keep it from happening again. In addition to whole barley, the ration now contains a commercial 38% protein-mineral-vitamin pelleted supplement. I mix enough supplement into the barley so that the ewes receive their daily NRC requirements of calcium through the hay and grain ration and do not have to rely on the free choice mineral to meet their calcium needs. A blood sample from the downed ewe had revealed a calcium level of 2.69 (normal range is 9.1 to 10.8).
Milk fever is different in sheep as compared to dairy cattle in that ewes oftentimes develop symptoms pre-lambing, as was the case here. Milk fever may also occur around lambing, as the ewe's hormones may inhibit her ability to sufficiently mobilize calcium reserves. The symptoms of milk fever and ketosis are similar, though milk fever seems to develop more suddenly. The differential diagnosis is the ewe’s response to calcium therapy. The key to both conditions is early recognition, proper treatment and eliminating the predisposing factors.
Editor's note: Both ewes gave
birth to and raised healthy sets of twin lambs.
Copyright © 2002.
Resources and suggested additional reading (links verified
Diseases and Disorders Commonly Seen in Ewes Just Prior to or Shortly After Lambing
Hypocalcemia (milk fever) - InfoVets
Nutritional effects on sheep health - University of Missouri
Parturient Parasis in Sheep and Goats - Merck Vet Manual
[PDF] Pregnancy toxemia vs. milk fever
Created or last updated
by Susan Schoenian on