Pneumonia is one of the most common respiratory problems encountered by sheep and goat producers. While pneumonia may be much less common a problem than other health concerns such as internal parasites, it can still cause significant losses in production and occasional death loss within any given herd. Occasionally, producers may experience an outbreak of disease that leads to numerous animals affected and severe losses. My experience suggests that summertime represents an increased number of cases in southwest Missouri.
Pneumonia is actually a broad term used simply to describe inflammation within the lung tissue. This inflammation can be caused by any number of different initiating factors.
Sheep and goats, like all other species have natural defense mechanisms that protect the respiratory system from potential invaders. Stressful conditions such as hauling and commingling animals, heavy parasite loads and harsh environmental conditions can serve as predisposing factors to pneumonia. Numerous potential pathogens are found as normal inhabitants of the respiratory tract of the sheep or goat. When given the opportunity by a compromised immune system, these agents set up infection and cause pneumonia.
Pneumonia in sheep and goats often begins with a viral or mycoplasmal infection that leads to a more severe secondary bacterial pneumonia. Common viral agents include parainfluenza 3 virus (PI3), adenovirus and respiratory syncytial virus. Mycoplama spp have also been shown to commonly contribute to pneumonia in small ruminants. These agents will often cause more mild forms of pneumonia within a herd of animals. If complicated by secondary bacterial invaders like Pasteurella multocida or Mannheimia hemolytica the pneumonia can become severe and even acutely fatal. In terms of parasites, lungworms can cause primary pneumonia or can serve as contributing components to other infectious causes.
Animals with pneumonia will generally run a fever, become depressed and less aggressive over feed. Most animals will have a nasal discharge and moist cough. After a diagnosis of pneumonia is made, animals should be isolated from the remainder of the herd and treated appropriately. Typically a course of antibiotics and an anti-inflammatory is indicated plus/minus an anthelmintic if lungworms are suspected. If numerous cases are popping up in a given herd, several practices may help to minimize the number and severity of cases on your farm. A pneumonia vaccine is available for use in sheep and goats that targets immunity against P. multocida and M. haemolytica. Additionally, providing a well-ventilated and clean environment is also important for respiratory health. Pay special attention to housing/shelter conditions and work to minimize dust and ammonia concentrations in the air. Minimize transportation stress and quarantine new animals for 2-4 weeks post arrival. Lastly, ensure excellent nutrition and manage your herd in a way to minimize intestinal parasite loads. These practices will go a long way to help protect your herd from an outbreak of pneumonia this summer.
Darren Loula, DVM, is a large animal veterinarian at Fair Grove Vet Service in Fair Grove, Mo.
