Dr. Bill Shulaw, OSU Extension Veterinarian
The starvation/hypothermia complex usually comes about when multiple contributing factors are present and not just the simple occurrence of cold weather. Some of these include failure of the ewe to care for the lamb, difficult birth resulting in a weak lamb, bacterial mastitis in the ewe, “hard bag” in the ewe caused by ovine progressive pneumonia virus, and several infectious causes of abortions which also may result in live, but weak, lambs. Most producers will be confronted with the occasional hypothermic lamb.
A comprehensive source of information about problems occurring around lambing time is the Sheep Production Handbook published by the American Sheep Industry Association. The following is from the current edition of the Handbook:
“Rectal temperature is the primary guide to identification and treatment of hypothermia in lambs. Mild to moderate hypothermia is characterized by a body temperature between 37° and 39°C (98° and 102°F); severe hypothermia occurs when the body temperature is below 37°C (<98°F). Hypothermia is caused by excessive body heat loss coupled with reduced heat production. Newborn lambs are unable to regulate their body temperature for the first 36 hours after birth so environment and management practices greatly affect how much body heat newborn lambs may lose. Energy from body fat, colostrum, and milk is required by lambs to generate heat. Starvation depletes stored energy sources quickly and precludes the intake of adequate amounts of high energy nutrients. Common, but not necessarily routine, findings on necropsy that suggest starvation include: the absence of milk in the stomach and intestine, a change in the color and consistency of fat around the kidneys from light tan and firm to purple and gelatinous, and a complete absence of fat in the abdomen.”
There are multiple approaches to treatment of lambs that are hypothermic. Again quoting from the Sheep Production Handbook :
“Hypothermic lambs do not get better without assistance. For treatment of hypothermia, the following steps are recommended:
1. Move ewe and lambs to shelter or, if the hypothermia is severe, remove lambs from the ewe.
2. PRIOR TO WARMING, lambs more than five hours old with severe hypothermia (< 37°C, 98°F) should be given an intraperitoneal injection of a warm 20 percent dextrose (glucose) solution at a dose of four to five milliliters per pound of body weight. The injection can be given by the following procedure: (1) hold the lamb by the back legs in a hanging position, (2) disinfect the injection site that is located one inch either side and one inch behind the navel, (3) slowly insert a 20-gauge, one inch sterile needle, with the syringe containing the dextrose attached, into the abdomen, and 4) direct the injection toward the rump.
3. Towel-dry wet lambs. Supplement with heat or warm in a warming box using dry heat, e.g., a hand-held hair dryer or heat lamp. Temperature in the box should not exceed 103°F. Avoid overheating lambs by affixing a thermometer to the inside of the box and checking the lambs and the box thermometer regularly, at least every 30 minutes. Lambs should be warmed to 99°F.
4. Tube feed colostrum at the rate of 20 to 25 milliliters per pound of body weight per feeding after the lamb has been warmed (30 milliliters is approximately equal to one fluid ounce). Lambs unable to nurse on their own should receive this amount of colostrum by stomach tube three to four times during the first day of life.
5. Return the lambs to the ewe when rectal temperature is normal (usually one to three hours), and they can stand and nurse on their own. If lambs are still weak after treatment, they should be fed regularly by stomach tube until they are strong enough to join their mother.
6. If only one of a set of twin lambs is involved, remove both lambs from the ewe while warming is taking place and return both lambs simultaneously. Observe lambs frequently to check for relapses.”
Your veterinarian should instruct you in the technique of intraperitoneal injection and can provide you with sterile glucose solution. If you find yourself unprepared, tube feeding the lamb a warm (102 F) corn syrup solution (like Karo®) may be helpful. Two ounces of a 50:50 mix of corn syrup and warm water through a stomach tube will provide both heat and readily available glucose to a cold lamb. This can be repeated hourly or so if the lamb appears to be responding.
Moderately hypothermic lambs may respond to warming them and tube feeding with milk or colostrum. If the ewe has no milk and you can’t get milk from another ewe, milk from your refrigerator that has been warmed to body temperature can be substituted safely.
Much has been written about colostrum and its importance to the health of newborn mammals. Again from Sheep Production Handbook:
“Many infectious diseases occurring in the first few days of life occur because the lamb did not get enough colostrum during the first 12 hours after birth. The newborn lamb, unlike the human baby, is born without protective proteins, called antibodies, in the blood. Antibodies are necessary to protect the lamb from bacteria and viruses that gain entrance into the body by various means. The first milk of the ewe, called colostrum, contains antibodies necessary for lamb survival. Colostrum antibodies against some diseases, such as the clostridial diseases, can be increased by vaccinating the ewe a month before lambing. The antibodies consumed by the lamb pass from the intestines into the blood stream. However, a gradual closure of the intestine to the passage of antibodies occurs and is completed by approximately 12 hours after birth. Therefore, it is extremely important for the lamb to get colostrum as soon after birth as possible. Colostrum also contains concentrated levels of energy, protein, vitamins, and other nutrients needed by the lamb. To ensure survival, the lamb should consume an amount of colostrum equal to five percent of its body weight. For example, a 10-pound (160 oz.) lamb should receive eight ounces of colostrum within the first few hours after birth, four ounces immediately, and an additional four ounces within the next 12 hours. It is easier, quicker, and more effective to use a stomach tube rather than a bottle to feed colostrum to a weak lamb.”
Although it is possible to use cow or goat colostrum as a substitute for ewe colostrum, shepherds should carefully weigh the risks of doing so. Colostrum from outside sources, including other sheep flocks, can bring unwanted disease causing bacteria and viruses to the farm. Some examples include Johne’s disease and salmonella, and very recent research has suggested that scrapie may be transmitted by milk or colostrum.1,2
The above quotations are from pages 423, 424, and 426 of the SID Sheep Production Handbook, 2002 Edition, volume 7, published by the American Sheep Industry Association, 9785 Maroon Circle, Suite 360, Centennial, CO 80112. Phone: (303) 771-3500. (Email: email@example.com)
1. Lacroux C et al. Prions in milk from ewes incubating natural scrapie. PLoS Pathog. 2008 Dec;4(12):e1000238. Epub 2008 Dec 12.
2. Konold T et al. Evidence of scrapie transmission via milk. BMC Vet Res. 2008 Apr 8;4:14.