To add to this confusion, it is impossible to distinguish acute cases from cases that have a high titer from past exposure. High titers commonly persist for more than a year after initial exposure. What this means is that the burden for diagnosis and quick treatment is placed on the veterinarian in the field. Instead, any combination of these signs may be present, with only the rare case showing most of them. It should be remembered that colitis does not always result in colic or diarrhea.
Mild colitis can result in depression and anorexia, with or without fever.
Normal feces may be passed, and signs of colic may be absent. Simultaneous auscultation and finger percussion often results in a high-pitched resonance in the dorsal abdomen. These signs of ileus are the most consistent clinical findings in all cases and take on added significance when they occur in the face of no signs of colic and passage of normal feces. The fever might be biphasic, Palmer says, with the first phase often going undetected unless the horse's temperature is monitored on a routine basis. The initial, or first phase, of the fever, which can range from 103 to 106 Fahrenheit, normally disappears within hours.