Coughing in sheep is seldom dangerous with one exception: chronic coughing can cause rectal prolapse, a fatal condition where the rectal tissue protrudes from the body. The condition is most often seen in black-faced feedlot ewe lambs with extreme tail docking. The coughing is not related to the docking, but can trigger the rectal prolapse. The market lamb is usually slaughtered. When the sheep is more valuable it can be treated by tissue amputation, replacement or by inserting hose-like prolapse rings to secure the rectum in place. Watch for rectal prolapse in coughing sheep and call the vet.
Parasitic nematodes, usually muellerius capillaris, can inhabit the lower respiratory tract of sheep and cause coughing. The condition presents symptoms like pneumonia or bronchitis. This is often seen on farms with moist and cool grazing lands. The coughing can be moderate to severe and persistent. You may notice weight loss or low milk yields in dairy sheep and these may be accompanied with subclinical infections. Untreated it can lead to respiratory distress and failure. When the infestation is acute the sheep may drool and hang the head forward.
Barn cough is the most common kind of cough in sheep. The cough is hacking and non-productive. You may see it most often in growing lambs. The more severe the coughing, the greater the chance of rectal prolapse. The causes of barn cough are dust, dusty feed, the stress of a crowded barn or damp weather. Most lambs will outgrow the cough but it can return if conditions are not addressed.
A veterinarian should be called if a cough persists. She will treat the sheep with tbenzimidazoles (fenbendazole, oxfendazole and albendazole) and macrocyclic lactones (ivermectin, doramectin, eprinomectin and moxidectin.) Infestation in herds will be treated by vaccination. Animals at pasture should be moved inside for treatment. Preventive precautions include separating livestock on grazing ground.
Barn Cough Treatment
Dampen the food if lamb cough only at feeding. If activity brings on the cough, the pens may be dusty, so spray them lightly with water. Coughing all day can mean there is an infectious agent. Antibiotics such as long-acting tetracycline should be given every other day for six days. When antibiotic treatment and lowering dust conditions does not stop the coughing, the infection may be viral. Keep the lamb calm and let it ride it out.