North American Veterinary Licensing Examination (NAVLE) Practice Test

The clinical presentation of an adult pig displaying petechial hemorrhage in multiple organs, along with ataxia, strongly aligns with Classical swine fever (CSF). CSF, also known as hog cholera, is a viral disease caused by the Classical swine fever virus (CSFV), which can lead to severe systemic illness in pigs.

In cases of CSF, petechial hemorrhages are common and can be observed in various tissues, such as the lungs, lymph nodes, and kidneys. These hemorrhages occur due to the virus-induced damage to the vascular endothelium and subsequent thrombocytopenia (low platelet count), which impair the animal's ability to form clots properly. Along with these hemorrhagic signs, neurologic symptoms like ataxia (lack of voluntary coordination of muscle movements) may also manifest, leading to an atypical presentation which can complicate diagnosis.

The other conditions, while they may present with some overlap in clinical signs, do not typically combine the severe petechial hemorrhage with ataxia in the same manner as seen with CSF. For instance, Haemophilus parasuis often leads to Glasser’s disease featuring septicemia and polyserositis, while Hem