Poultry health


The majority of diseases in poultry are caused by viruses, bacteria, parasites and other pathogens, which are transmitted in different ways. There are also so-called metabolic or nutritional diseases which are not infectious.

When the parent contaminates her offspring in the egg, we speak of “vertical” transmission.

When there is spread of disease between birds within a flock, we speak of direct horizontal transmission. We say it is indirect if the pathogen is transmitted by equipment, insects, etc.

As an introduction, we recommend watching this video covering bird health basics, prepared by the Canadian Food Inspection Agency (CFIA).

For more details, continue reading here on the following different topics:


Vaccines are usually given to breeding birds to protect their offspring. In some cases, birds are vaccinated at the hatchery or breeding farm. It is not possible to vaccinate a small batch of poultry. In case of illness, contact a veterinarian.
If the veterinarian makes a diagnosis in your chicken or other poultry farm, or if you suspect that animals are sick:

  • Avoid selling or buying birds.
  • Avoid participating in exhibitions or visiting other breeders.
  • Isolate all sick birds and treat them, if necessary. Do not eat their flesh or eggs.
  • In your routine, take care of sick animals last.
  • Wash and disinfect the equipment after use.
  • Wear protective clothing, such as a coveralls, gloves and a face mask, when caring for sick birds.
  • A veterinarian must carry out euthanasia if the animal cannot be treated.


The use of medicines intended for farmed animals is governed by laws and regulations. These medications must be prescribed by a veterinarian who will specify the waiting periods to be respected before processing meat poultry or consuming eggs.

The following tables present various clinical signs observed in farms and the corresponding diseases. It is important not to make a diagnosis on your own and to consult a veterinarian.

Respiratory problems
Digestive problems
Skin and feather problems
Lameness problems
Sudden mortality

To learn more about common diseases, consult the Fact Sheets on 20 diseases of importance in poultry production and recommended biosecurity measures developed by the Association of Veterinarians in the Animal Industry (AVIA).

Canada has established a list of 32 notifiable animal diseases (NOADs) that are generally of great importance to health (animal or human) or the Canadian economy. Four of them can affect poultry:

Animal owners, veterinarians and laboratories are therefore required to immediately report the presence of an animal that is affected or suspected of being affected by one of these diseases to the CFIA.

Contact a veterinarian in your area. To do this, consult the MAPAQ list of Veterinary support for backyard livestock at the following link:


Otherwise, you can contact the Order of Veterinary Physicians (OMVQ). If you are unable to find a veterinarian and you notice significant mortalities in your farm, contact the MAPAQ reporting center at 1 866 381-1717.

If a veterinarian suspects the presence of one of the four notifiable diseases, you or your veterinarian must immediately notify the CFIA district office nearest you. If you cannot reach your local district office, call the CFIA reporting center at 1-866-806-4115. Also notify the Quebec Poultry Disease Control Team (1 888 652-4553).

If infectious laryngotracheitis or Mycoplasma gallisepticum mycoplasmosis is suspected or diagnosed, you or your veterinarian should contact the MAPAQ Avian Network.

Zoonoses are infectious diseases that can be transmitted to humans from animals. In poultry, the most common zoonoses are:


A bird carrying one of these diseases may not show clinical signs. The MAPAQ website presents fact sheets on zoonoses.

It is not recommended to drink, eat or smoke in a chicken coop, especially after handling sick animals. If you think you have a zoonosis, call Info-Santé at 811 or consult a doctor.

Eggs and poultry products can be a source of food poisoning. For example, eggs may contain the bacteria Salmonella enteritidis (SE). Eggs produced in backyard flocks may carry a risk; they should therefore be well cleaned and washed, and eaten well cooked.

For more information, visit the Department of Agriculture’s website on Foodborne Infections and Basic Food Preparation Rules.

In all circumstances, euthanasia must be carried out humanely, in a manner that results in total and irreversible loss of consciousness. For information, MAPAQ has published the Guide to on-farm insensitization and euthanasia for specialty and backyard poultry.

Chicken Farmers of Canada also offers a brochure on on-farm chicken euthanasia.