Salmonellosis is a disease caused by Salmonella spp bacteria. It can cause digestive issues in infected animals.
There are over 2,000 serotypes of Salmonella. Salmonella exists in many animal species. It can survive for months in soil, water and excrement.
Salmonellosis is a zoonotic disease, which means it can be transmitted between animals and humans. Salmonella bacteria often causes food poisoning. Visit the Salmonellosis page to learn more about the disease in humans.
Almost all animals can be infected by salmonella.
Some of the most frequently infected animals are poultry and swine. Salmonella is also regularly found in cattle.
Cats and dogs can also become infected.
There are several exotic pets that are at risk of salmonellosis, including turtles and hedgehogs. Most snakes and lizards are also carriers of the bacteria.
Signs of the disease
Infected animals do not generally show any symptoms, but they can still excrete the bacteria into their environment.
When there are signs of the disease, they vary from species to species.
Poultry with salmonellosis may exhibit:
- Lameness (arthritis)
- Difficulty breathing
Clinical signs can sometimes be detected in cattle:
- Bloody or watery diarrhea
- Fever, depression, loss of appetite
- Drop in milk production
- Abortion (Salmonella ser. Dublin).
Salmonella can sometimes be found in a calf's bloodstream and cause severe systemic disease, especially serotypes Typhimurium and Dublin. Such cases may exhibit diarrhea, pneumonia and septicemia and can be fatal.
Calves that are less than three months old are the most vulnerable and exhibit the most severe clinical signs.
In other animals
Salmonellosis can cause abortion and diarrhea in sheep and goats.
Dogs and cats may present with fever, lethargy, anorexia and sometimes diarrhea and vomiting.
Pigs, especially piglets between two and four months old, may exhibit fever, diarrhea and septicemia.
Infected animals can transmit the disease to humans, even if they show no symptoms.
Salmonella is generally found in the intestines and feces. It is primarily spread by the fecal-oral route.
Salmonellosis can be introduced into a herd through the arrival of an infected animal, visitors with contaminated hands or boots, or poorly cleaned equipment.
Contaminated food can also cause salmonellosis in animals. For example, cats and dogs that are fed raw meat are more likely to contract the disease.
Sick animals sometimes require supportive treatment to lower a fever or rehydrate. If an animal is in critical condition, antibiotics may be necessary.
Protection and prevention
Families adopting a pet should choose the type of animal with care. Some people are more vulnerable to diseases like salmonellosis, including pregnant women, young children, seniors and people with weakened immune systems. These individuals should avoid higher-risk animals like turtles, snakes, lizards, hedgehogs and other exotic animals and cats and dogs that are fed raw meat.
If you are getting animals for a backyard farm, follow the recommendations for preventing frequent cases of salmonellosis in small flocks (in French only).
Several routine hygiene rules (in French only) can help prevent animal contamination on farms.
Outdoor birdfeeders should also be managed with care. We recommend following the guidelines for feeding wild birds (in French only).
Poultry farmers should adopt strong biosecurity measures for their flocks. These measures are important as they help control vermin and limit risks related to potentially contaminated equipment or visitors.
Farmers should also vaccinate breeding flocks.
Preventing and controlling Salmonella infections in cattle first requires implementing the appropriate biosafety and herd management practices.
Salmonella contamination often occurs when a new animal is introduced into the herd. It's important to find out the health status of the herd the animal is coming from before purchase, especially for Salmonella Dublin.
Limit the incidence of the disease by paying particular attention to your animals' immune systems, especially for calves.
Dairy farmers can receive visits from a veterinarian to prevent Salmonella Dublin through the Programme intégré de santé animale du Québec. Learn more on the Visite zoosanitaire dans les élevages de bovins laitiers webpage (in French only).
Two Salmonella serotypes are closely monitored in Québec: Salmonella ser. Enteritidis in flocks of egg-laying hens and Salmonella Dublin in herds of dairy cows. These serotypes can seriously impact agricultural production and public health.
Salmonella Enteritidis is of particular concern for human and animal health, especially poultry. This serotype is unique because hens and other poultry can not only transmit it through their excrement, but also through the reproductive system to their eggs and offspring.
Eggs for consumption
Salmonella is checked for throughout the different steps of the egg production process. These checks occur in hatcheries, in pullet and layer flocks and at egg grading stations.
If a sample tests positive for Salmonella Enteritidis, corrective measures are taken. For example, contaminated eggs are recalled from the market. The farm environment is also tested before introducing other hens.
Salmonella Dublin can seriously impact cattle herd health. It is resistant to several antibiotics, making treatment more difficult.
This serotype is specifically adapted to cattle. Multiple animals could transmit the disease without exhibiting any clinical signs and maintain the infection in a herd by sporadically excreting the bacteria. These animals will be asymptomatic carriers for their whole life.
Salmonella is mainly excreted in the feces, but it can also appear in vaginal secretions, urine, milk, colostrum and saliva. This means newborn calves are easily infected. They are very vulnerable to the disease, which is often fatal for them.
Testing for salmonellosis is recommended for herds that show signs of a Salmonella Dublin infection. For herds that show no signs, periodic testing is still recommended based on the level of risk.
For more information, view the Surveillance, prévention et contrôle des infections à Salmonella Dublin dans les élevages laitiers et vache-veau document (PDF 781 Kb) (in French only).
Last update: August 28, 2023