Pneumonia is a major health problem among all ages and classes of sheep. It can be caused by a number of organisms and foreign bodies affecting the lungs. The combination of viral and bacterial microorganisms with an elevation in stress is the primary cause of acute pneumonia. Moisture and temperature extremes are major factors contributing to stress. In New Mexico, moisture generally is not a common stress factor, but the extreme temperature changes during the fall are.
Acute pneumonia can affect lambs from birth to yearling age. They are probably infected early in life by the causative microorganisms, but they may resist the infection until some stress occurs, such as extreme changes in temperature, exposure to dust, shipping, or extended periods without feed. Afflicted lambs generally weaken, refuse feed, appear gaunt, and breathe rapidly. Depending on the time it occurs, the condition often is referred to as shipping pneumonia or acute summer pneumonia. Proper management from lambing throughout the life of the lamb is necessary to minimize the incidence of pneumonia.
When shed lambing, keep the premises clean, dry, and as draft-free as possible. The lambing shed should be well ventilated and moisture should be kept to a minimum. Avoid over-confinement. Shear ewes before lambing to reduce infection from wool tags around the udder.
Proper nutrition of the ewes is important. Vitamin C deficiency has been associated with the incidence of pneumonia. Treatment should consist of using broad-spectrum antibiotics as directed on the label. Reducing stress and administering high levels of antibiotics during susceptible periods may be of some value in reducing the incidence of pneumonia.