Which disease is characterized by bronchitis and pneumonia in laboratory animals?

The disease characterized by bronchitis and pneumonia in laboratory animals is indeed linked to the Sendai Virus. This virus is a paramyxovirus that primarily affects rodents, particularly mice. When infected, animals may exhibit respiratory symptoms, including inflammation of the bronchi (bronchitis) and lung tissue infections (pneumonia). The Sendai Virus is known for its rapid spread in mouse colonies, which can lead to significant morbidity and mortality due to severe respiratory distress.

In contrast, while Pasteurellosis is a bacterial infection that can also affect the respiratory system, it is not primarily associated with the specific combination of bronchitis and pneumonia as prominently as the Sendai Virus. Mycoplasmosis, caused by Mycoplasma pulmonis, can lead to similar respiratory issues, but it typically results in more chronic symptoms rather than the acute respiratory infections associated with Sendai Virus. Mouse Hepatitis Virus, on the other hand, primarily affects the liver and can also impact the central nervous system, but it does not typically present with primary respiratory symptoms like bronchitis or pneumonia.

Thus, the Sendai Virus is recognized specifically for causing acute respiratory diseases in laboratory animals, making it the correct choice for this question.