Cases of Blisters Not Caused by FMD or SVV Demonstrate Value of Rule Out Testing

The Manager of the Canada West Swine Health Intelligence Network says rule out testing is the most certain way to ensure blisters in pigs are not caused by Foot and Mouth Disease or Seneca Valley virus.

CWSHIN's just released swine health surveillance report for the second quarter outlines two incidents where sows traced back to farms in Manitoba and Saskatchewan showed signs of blisters and triggered Foot and Mouth and Seneca Valley virus rule testing but were negative for both.CWSHIN Manager Dr. Jette Christensen suggests this demonstrates the importance of rule out testing.

Quote-Dr. Jette Christensen-Canada West Swine Health Intelligence Network:

It's a complex investigation because first CFIA needs to rule out Foot and Mouth Disease and Seneca Valley Virus or other viruses that can cause blisters and then the herd practitioners will come in to figure, if it's not Foot and Mouth Disease, it's not Seneca Valley virus, what is it?One of the cases had laboratory histopathology done that suggested that it could be burns.

Burns, in a pathological context covers frostbite, sunburns, chemical burns, so it's a wide range of different causes.But the veterinarian couldn't find anything that could cause burns in the barns.So, we know for that specific herd that it wasn't Foot and Mouth, it wasn't Seneca Valley but we're not absolutely sure what it was.

Same story in the other farm.Seneca Valley Virus, Foot and Mouth Disease, any other viruses that could cause blisters were ruled out.They did see some chemicals that might have caused burns but they don't have confirmation in the laboratory.Bottom line for both of these cases was we know what it was not but we are not certain what it was.

Dr. Christensen says there are blisters out there but not all are caused by bacteria or viruses so it's critical for our Foot and Mouth Disease and Seneca Valley virus surveillance for every case of blisters to be investigated.