Blisters can signal serious diseases that impact animal health and trade. The Outbreak Support Network helps producers and veterinarians understand what to look for, what happens next, and how to respond quickly to protect the Canadian pork industry.
Outbreak Support Network:
Responding to Blisters in Pigs
What You Need to Know
Blisters (vesicles) are a concerning sight in any barn because:
- Blisters can be caused by both diseases that are federally reportable to the Canadian Food Inspection Agency (CFIA) or diseases that are not reportable. Both types of diseases, however, can lead to concerns at export.
- Healed skin lesions, like wounds or burns, may look like healed blisters
- Any case of blisters or suspicion of blisters will lead to a complex disease investigation that must involve CFIA, producers, herd veterinarians, provincial Chief Veterinary Offices (CVO), provincial pork organizations, and laboratories.
Knowing what to do and what will happen next is key to managing your barn and protecting the Canadian pork sector at large from potential trade disruptions that could be caused by a federally reportable disease outbreak.
The Outbreak Support Network (OSN) has developed some information and tools that may help you know your role in the complex disease investigations that follows when Blisters are seen or suspected in your pig barns
Blisters & Diseases – Similar But Different
There are four diseases affecting pigs that cause blisters that look very much alike, but are very different. These diseases are:
FMD
Foot and Mouth Disease
VSV
Vesicular Stomatitis Virus
SVD
Swine Vesicular Disease
SVA
Senecavirus A
At first glance, clinical signs of these diseases are indistinguishable. Collectively, they are known as viral vesicular diseases. Other viruses like Porcine Parvovirus and Swine pox can also cause blisters, but these are usually identifiable through other signs.
Blisters can also be caused by non-infectious exposure such as:
Trauma (wounds, tears)
Chemicals
Sunburn or Frostbite
Feed
Toxins
Plant Awns
FMD, VSV and SVD are all federally reportable diseases, so when animals in a herd have blisters, the discovery must be reported to CFIA.
Therefore, also blisters caused by SVA are reportable to CFIA because they are indistinguishable from blisters caused by FMD. Laboratory tests are required to rule out a reportable disease and to diagnose SVA. SVV is less likely to cause a large-scale disruption to international pig and pork movements, however the presence of SVA at assembly yards and in the USA has caused disruption to movements of cull sows both through Manitoba (2023) and Ontario (2025).
What Happens Next?
Navigate our interactive flow charts below to see what happens next if skin lesions are reported by...
More Information
For more information, please see resources below:
Reports
SVA info synopsis BA Aug
Reports
SVA info synopsis BA Aug
Reports
Senecavirus A Incidence in U.S. Breeding Herds A Decade of Surveillance
Reports
Senecavirus A Incidence in U.S. Breeding Herds A Decade of Surveillance
Reports
Idiopathic vesicular disease in swine in Manitoba
Reports
Idiopathic vesicular disease in swine in Manitoba
Reports
Validation of a competitive ELISA and a virus neutralization test for the detection and confirmation of antibodies to Senecavirus A in swine sera
Reports
Validation of a competitive ELISA and a virus neutralization test for the detection and confirmation of antibodies to Senecavirus A in swine sera
CWSHIN Library
For those that have access to the CWSHIN library, see additional resources below:
Provincial CVO Office and Industry Contacts:
In case of vesicular disease suspect or Senecavirus A virus detection in a swine herd:
CVO
Dr. Glen Duizer
Manitoba Pork Producers
204-237-7447
During Business hours
1-833-310-0108
24-hour emergency line
Office of the Chief Veterinary Officer
CVO
306-787-2150
Office
Chief Veterinary Officer- Dr. Stephanie Smith
Surveillance Veterinarian - Dr. Wendy Wilkins
Sask Pork
Office of the Chief Provincial Veterinarian
CVO- Dr. Keith Lehman
8:15 am to 4:30 pm
(open Monday to Friday, closed statutory holidays)
(open Monday to Friday, closed statutory holidays)
Alberta Pork
Darcy Fitzgerald, Executive Director
Javier Bahamon, Quality Assurance and Production Manager
CVO
Dr. Teresa Burns, Office of the Chief Veterinary Officer
1-800-661-9903
Toll free
Monday-Friday, 8:30 AM to 4:30 PM