Enrollment of horses that demonstrated severe adverse vaccine
reactions (reactors)
A group of 21 horses were accepted into the study for sample submission
purposes. These samples were defined as a horse that had experienced a
severe adverse reaction after vaccination either previously or during
the course of the current study. A questionnaire was completed either by
the owner or primary veterinarian (supplemental information). Clinical
signs exhibited by these 21 horses included severe swelling at the
injection site, fever, colic, laminitis, lethargy, and markedly stiff
neck. Blood was collected and processed as previously described.
Fourteen horses had blood drawn within 24 hours, two at 180 days, three
at 270 days and two at unknown times after vaccination. Horses ranged
from 2 to 15 years of age while age was not documented for 3 horses.
There were 13 Warmbloods, 4 Quarter horses and 3 horses did not have
their breed reported. Thirteen were geldings and 8 were mares.