Pneumonia is fairly uncommon in adult dairy cows due, in part, to adequate ventilation in facilities, vaccination protocols and the more competent immune function of adult cows versus calves. There are, however, some scenarios where pneumonia can become a serious problem in adult cows.
One such scenario is an outbreak of Bibersteinia trehalosi. Bibersteinia is a bacteria that is closely related to Mannheimia haemolytica, but causes a more severe pneumonia and rapid death.
Much of the research published on Bibersteinia has been performed on sheep. Studies have shown sheep can die as soon as eight hours after being infected. This can hold true for dairy cattle as well.
Bibersteinia is typically not an isolated event; multiple cows are usually affected. Fever occurs early in the disease course, and by the time the cow has noticeable difficulty breathing, she may no longer have a fever. Clinical signs include severely labored breathing, signs of shock and dehydration (sunken eyes), recumbency and death.
Diagnosis is typically made by necropsy sample submission and testing of lung and tracheal tissue. The previously described symptoms, along with severe hemorrhage in the trachea, raise suspicion of Bibersteinia even more. Treatment of Bibersteinia is generally ineffective due to the rapid disease course.
Economic losses associated with Bibersteinia can be significant. In addition to death loss, there are treatment costs and a general drop in milk production across the entire herd. A recent outbreak in our practice resulted in a 15 lb. per day milk drop in production across the entire herd until the outbreak was under control. Bibersteinia can also affect calves, with similar symptoms as seen in adult cattle.
Source Difficult to Track
It is usually unknown how Bibersteinia enters the herd; however, there can be carrier animals such as sheep and goats that harbor the bacteria. It is possible a stress event on the herd can be a trigger for an outbreak. That stress may be due to extreme weather, nutritional causes such as subacute rumen acidosis, viral insult, etc. In outbreaks seen in our practice over the past several years, severe cold seems to have triggered the spike in cases.
Prevention of Bibersteinia is much easier than treatment. Studies have shown some cross protection using commercially available Mannheimia/Pasteurella vaccines. Work with your veterinarian to determine the pros and cons of vaccination to prevent a Bibersteinia outbreak. Those herds that have experienced outbreaks usually incorporate a respiratory bacterin into their vaccination protocol to prevent the devastation of the outbreak from occurring again. These herds also pay particular attention to viral vaccination methods to minimize nutritional stress such as subacute rumen acidosis.
Pneumonia in both adult cows and calves can be caused by many different pathogens as well as a combination of several pathogens. If you experience higher than expected death due to pneumonia consult with your veterinarian about the situation, especially if Bibersteinia is suspected. A necropsy should be performed on adult cows that die of suspected pneumonia or any other unexplained reason.
Your veterinarian might decide to collect and submit samples for diagnostic testing at the time of necropsy. In some cases, Bibersteinia can be found in healthy lung tissue and nasopharynx. Your veterinarian can also help decipher your test results in order to determine the best course of action for your herd.