Advice for Veterinarians and Swine Producers - H1N1 Flu Virus

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What is swine influenza?

Swine influenza is a contagious respiratory disease of pigs. The disease is commonly seen in North and South America, Asia and Europe. Illness is caused by Type A Influenza viruses, which also affect a range of other animals, as well as humans.

Influenza viruses are commonly detected in pigs, which can become infected by humans, birds or other pigs. The transfer of influenza from pigs to humans is rare and usually involves close contact with sick animals. However, the CFIA is asking veterinarians and producers to increase their biosecurity measures to limit any risks to human or animal health.

The CFIA is working with its provincial and territorial counterparts to monitor swine herds and to encourage producers to maintain strict disease prevention measures.

What are the symptoms in pigs?

Signs of swine influenza include the following:

  • fever
  • loss of appetite
  • weight loss
  • coughing
  • sneezing
  • nasal discharge
  • difficulty breathing
  • reduced fertility or abortion

How can pigs be protected?

The following actions can potentially prevent swine influenza:

  • vaccinating animals
  • ensuring farm workers maintain good hygiene
  • following strict biosecurity practices
  • providing adequate ventilation in barns
  • identifying and segregating sick animals as early as possible

What precautions should producers take to limit the risk of introducing and spreading disease?

Traffic control:

  • Anyone exhibiting signs of respiratory illness should avoid contact with animals.
  • Workers in swine facilities who have been exposed to influenza or someone diagnosed with influenza should avoid contact with animals until they have been checked by a healthcare worker.
  • Avoid contact with swine outside regular employment.
  • Control and restrict visitors' access to the herd.
  • Require all visitors to wear clean boots, clothing and gloves and wash hands thoroughly on entry and exit.
  • Prevent other animals from coming into contact with the herd.
  • Maintain records of the movement of people, animals and equipment on and off the premises.


  • Only obtain new animals from reputable sources and limit the frequency of introducing new pigs to the herd.
  • House newborn, weaned, feeder, and breeding pigs separately.
  • Move pigs in groups during each production stage, in an all-in-all-out manner.


  • Routinely clean and disinfect buildings, barns, equipment, clothing and footwear.
  • Designate a cleaning area for vehicles and equipment.
  • Promptly dispose of dead pigs in a manner that minimizes the chance of spread of any disease.
  • Implement a manure management program.
  • Avoid borrowing equipment and vehicles from other farms.

Herd health management:

  • Monitor herd health daily and employ veterinary services.
  • Uniquely identify all groups of animals for traceability purposes (where they came from and where they are sold to).
  • In consultation with a veterinarian, consider vaccinating animals.
  • Isolate sick pigs and immediately report any signs of illness to your veterinarian or the nearest CFIA office.

Program maintenance:

  • Train all staff on your biosecurity program and monitor its effectiveness.
  • Be aware of any diseases in your area and adjust your biosecurity program accordingly.
  • Recommend farm workers discuss an annual flu vaccination with their doctor. (Vaccination may reduce the amounts of virus shed if infected during human influenza outbreaks, and limit the potential for human influenza virus infection of pigs. The effectiveness of current human vaccines against this new strain is not known at this time.)

What precautions should veterinarians take when investigating respiratory illnesses in swine?

The CFIA recommends that veterinarians:

  • prepare and plan the visit by contacting the producer beforehand;
  • park in designated areas or as far as possible from animals;
  • keep a log book of farms visited;
  • wash hands thoroughly after handling animals;
  • leave as you arrived and clean and sanitize vehicles and equipment;
  • dispose of protective equipment in a safe manner:
    • either leave it on the farm to be appropriately disposed or
    • remove it and place it in “contaminated materials” containers for transport to the office;
  • prioritize work by attending low-risk jobs first and then observe animals for concerns; and
  • avoid or minimize contact with manure storage, feed supplies, and water supplies.

Until more is known about how this illness affects swine, if swine influenza is suspected – do not travel to another swine farm for 48 hours.

For more detailed information on biosecurity measures recommended for disease investigation farm visits please contact your local CFIA office.

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