This is the smoldering low-level illness and cranioventral consolidation of Mycoplasma hyopneumoniae, also called “enzootic pneumonia.” Follow this link to see lung tip atelectasis (dark, collapsed areas on tips – you can’t breathe with lungs like that).
M. hyopneumoniae causes mild endemic respiratory disease in pigs characterized by a dry cough and reduced weight gain. Stressors (parasites, other infections, even the weather) can result in severe pneumonia.
Swine influenza A virus varies in severity, and is characterized by rapid onset in whole herd of fever, depression, anorexia, coughing, followed by almost-as-sudden recovery.
Mannheimia hemolytica is more a sheep/goat/cow pneumonia (think shipping fever complex), but is often thought of in same risk category as Pasteurellae.
Glaesserella (formerly Haemophilus) parasuis is the cause of Glasser’s disease, seen mostly in piglets 6-8 wk old. Characterized by short course, sudden death. Clinical signs include high fever, severe coughing, abdominal breathing, swollen joints, CNS signs like lateral decubitus, paddling, trembling.
In addition to respiratory illness, look for reproductive problems (abortions, stillbirths) in sows with porcine reproductive and respiratory syndrome (PRRS).
Image courtesy of Meghann Pierdon, VMD, DACAW.