Public Health Notice: Outbreak of extensively drug-resistant Salmonella infections linked to raw pet food and contact with cattle

March 28, 2024 – Final Update

On this page

• Why you should take note
• Investigation summary
• Symptoms
• What you should do to protect your health
• Epidemiological information
• Additional information
• Media contact
• Public inquiries

Why you should take note

The Public Health Agency of Canada (PHAC) collaborated with federal and provincial public health partners to investigate an outbreak of extensively drug-resistant (XDR) Salmonella infections in six provinces.

Investigation findings identified two sources:

• Exposure to raw meat prepared for pets (raw pet food) was identified as a likely source for some of the illnesses reported in this outbreak. Some of the individuals who became sick reported exposure to raw pet food, or to dogs fed raw pet food, before their illnesses occurred. A single common supplier of raw pet food was not identified.
• Contact with cattle, particularly calves, was also identified as a likely source for some of the illnesses reported in the outbreak.

This investigation has been closed, however this outbreak is a reminder that Salmonella bacteria can be found in raw pet food and in many species of animals, including dogs and cattle. If contaminated, raw pet food can also make your pets sick. Infected pets can also spread bacteria, like Salmonella, to individuals they are in contact with, even if they do not show any signs of illness.

Always use safe food handling practices when preparing, cooking, or storing raw pet food to prevent illness. Practice good hand hygiene and frequent handwashing after contact with dogs fed raw pet food, cattle, and their environments.

Investigation summary

In total, 44 laboratory-confirmed cases of XDR Salmonella I 4,[5],12:i:- illness were linked to this outbreak in six provinces: Manitoba (1), Ontario (15), Quebec (24), New Brunswick (1), Nova Scotia (2), and Prince Edward Island (1). Individuals became sick between July 2020 and January 2024. Thirteen individuals were hospitalized. No deaths were reported. Individuals who became ill were between 0 and 91 years of age. Many of the cases (43%) were in children 5 years of age or younger. About half of the cases (55%) were female. Some illnesses associated with this outbreak strain were difficult to treat with commonly recommended antibiotics.

Using a laboratory method called whole genome sequencing, it was determined that some Salmonella illnesses dating back to 2020 were caused by the same outbreak strain as the illnesses that occurred in 2023 and 2024.

The outbreak strain of Salmonella that made people sick was found in raw pet food from the home of an ill individual. The outbreak strain of Salmonella was also found in sick dogs and cattle, and some of these animals died.

Symptoms

Symptoms typically start 6 to 72 hours after exposure to Salmonella bacteria, and usually last for 4-7 days.

Symptoms may include:

• fever
• chills
• nausea
• vomiting
• diarrhea
• headache
• abdominal cramps

People who are infected with Salmonella bacteria can spread Salmonella to other people several days to several weeks after they have become infected, even if they don't have symptoms. Salmonella can spread by person to person contact and contaminated surfaces. Most people who become ill from a Salmonella infection will recover fully after a few days without treatment, but it can also cause severe illness and hospitalization.

The Salmonella strain associated with this outbreak investigation is extensively drug-resistant, which means it's resistant to all commonly recommended antibiotics (ceftriaxone, azithromycin, trimethoprim/sulfamethoxazole, ampicillin, and ciprofloxacin). This outbreak strain is also resistant to older antibiotic drugs (aminoglycosides, chloramphenicol, and tetracycline). Illnesses resulting from this outbreak strain may be difficult to treat with commonly recommended antibiotics, if antibiotic treatment is considered necessary.

Anyone can become sick with a Salmonella infection. If you think you're experiencing symptoms from a Salmonella infection, contact your health care provider.

Those at higher risk for serious illness include:

• older adults
• young children
• people who are pregnant
• people with weakened immune systems

What you should do to protect your health

Follow the advice outlined in this section to prevent the direct or indirect spread of Salmonella and reduce your risk of becoming ill from exposure to raw pet food, to dogs fed raw pet food, or contact with cattle.

Raw Pet Food

PHAC does not recommend feeding raw pet food to pets, especially in households with young children or individuals who have a compromised immune system, as they are at greater risk for more serious illness.

• Harmful germs such as Salmonella and E.coli have been found in commercially prepared raw pet food and treats and can be found in many raw meats and products used in homemade diets.
• Animals fed raw meat diets (raw pet food) are more likely to pass (shed) harmful germs through their feces than those fed exclusively kibble or cooked diets, even when they appear healthy.
• When deciding what to feed to your pet, always talk to your veterinarian first. They can help you determine what is best to keep your pet and your family healthy.

If you choose to feed your pet raw pet food, the following tips may help reduce the risk of a Salmonella infection:

• Always wash your hands thoroughly with soap and water after feeding, playing, handling or cleaning up after pets.
• Wash and sanitize any containers, utensils and surfaces that have come into contact with raw pet food before using them again. This includes food and water bowls, countertops, microwaves and refrigerators.
• Use dedicated dishes and utensils to serve your pet and wash them separately from other dishes and utensils.
• Store all pet food and treats away from where human food is stored or prepared and away from reach of young children. Pick up treats and food bowls when your pet is done with them.
• Raw pet food may need to be stored frozen or refrigerated. If thawing raw food:
  • Keep your pet's food away from human food
  • Place it in a sealed, clean container that will hold any juices that may leak out
  • Thaw only as much as needed
  • Thaw on the bottom shelf of the refrigerator
  • Do not re-freeze food after thawing
• Don't allow your dog to lick your face, mouth, or open wounds.

Contact with Cattle

• Always wash your hands before and after you touch cattle, or anything in the areas where they live, roam or eat. Wash with soap and warm water for at least 20 seconds. Use an alcohol-based hand rub if soap and water are not available.
• If visiting a farm or petting zoo, wash your hands when you leave animal areas, even if you did not touch the animals directly.
• Do not eat or drink around cattle. Keep food and drinks away from animal areas.
• Always supervise children around animals, such as cattle. Do not let children put their fingers or objects (like pacifiers) in their mouths when they are around animals or in an animal area.

Epidemiological information

Figure 1 below is an epidemiological curve for this outbreak. Investigators use this information to show when illnesses begin, when they peak, and when they trail off. It can take several weeks from the time a person becomes ill to when the illness is reported and testing confirms a link to the outbreak. Data are available for 44 cases.

Figure 1: Text description

Table 1 – Number of people infected with XDR Salmonella I 4,[5],12:i:-, by month

Month of symptom onset or specimen collection	Number of cases
January 2020	0
February 2020	0
March 2020	0
April 2020	0
May 2020	0
June 2020	0
July 2020	2
August 2020	1
September 2020	0
October 2020	0
November 2020	0
December 2020	0
January 2021	0
February 2021	0
March 2021	0
April 2021	0
May 2021	0
June 2021	0
July 2021	1
August 2021	0
September 2021	0
October 2021	2
November 2021	4
December 2021	1
January 2022	1
February 2022	0
March 2022	0
April 2022	1
May 2022	3
June 2022	2
July 2022	3
August 2022	1
September 2022	1
October 2022	2
November 2022	0
December 2022	2
January 2023	0
February 2023	0
March 2023	3
April 2023	1
May 2023	1
June 2023	2
July 2023	4
August 2023	1
September 2023	2
October 2023	1
November 2023	0
December 2023	0
January 2024	2
February 2024	0
March 2024	0

Investigation history

Public Health Notice: November 11, 2023

Why you should take note

The Public Health Agency of Canada (PHAC) is collaborating with provincial public health partners, the Canadian Food Inspection Agency and Health Canada to investigate an outbreak of extensively drug-resistant (XDR) Salmonella infections in six provinces.

Many of the individuals who became sick are children 5 years of age or younger. Illnesses associated with this outbreak strain may be difficult to treat with commonly recommended antibiotics, if antibiotic treatment is needed.

The outbreak is ongoing, as recent illnesses continue to be reported to PHAC.

Based on the investigation findings to date, two sources have been identified:

• Exposure to raw meat prepared for pets (raw pet food) has been identified as a likely source for some of the illnesses reported in this outbreak. Some of the individuals who became sick reported exposure to raw pet food, or to dogs fed raw pet food, before their illnesses occurred. A single common supplier of raw pet food has not been identified.
• Contact with cattle, particularly calves, has also been identified as a likely source for some of the illnesses reported in the outbreak.

The outbreak investigation is ongoing and it's possible that additional sources may be identified.

The outbreak is a reminder that Salmonella bacteria can be found in raw pet food and in many species of animals, including dogs and cattle. Always use safe food handling practices when preparing, cooking, or storing raw pet food to prevent illness. Practice good hand hygiene and frequent handwashing after contact with dogs fed raw pet food, cattle, and their environments.

The outbreak strain of Salmonella that made people sick has been found in raw pet food from the home of an ill individual. If contaminated, raw pet food can also make your pets sick. Infected pets can also spread bacteria, like Salmonella, to individuals they are in contact with, even if they do not show any signs of illness. This outbreak strain of Salmonella has also been found in sick dogs and cattle, and some of these animals have died. This public health notice will be updated as the investigation evolves.

Investigation summary

As of November 11, 2023 there are 40 confirmed cases of XDR Salmonella I 4,[5],12:i:- illness in six provinces: Manitoba (1), Ontario (14), Quebec (21), New Brunswick (1), Nova Scotia (2), and Prince Edward Island (1). Individuals became sick between July 2020 and September 2023. Thirteen individuals have been hospitalized. No deaths have been reported. Individuals who became ill are between 0 and 91 years of age. Just under half (43%) of the cases are in children 5 years of age or younger. About half of the cases (53%) are female.

The collaborative outbreak investigation was initiated because of an increase in reports of XDR Salmonella illnesses in multiple jurisdictions across Canada. Using a laboratory method called whole genome sequencing, it was determined that some Salmonella illnesses dating back to 2020 were caused by the same outbreak strain as the illnesses that occurred in 2023. More recent illnesses may be reported in the outbreak because there is a period between when a person becomes ill and when the illness is reported to public health officials. For this outbreak, the illness reporting period is between 4 and 8 weeks.

Additional information

• Salmonellosis (Salmonella)
• Pet food and treats
• Pets: Healthy animals, healthy people
• General food safety tips

Media contact

Public Health Agency of Canada
Media Relations
613-957-2983

Public inquiries

Call toll-free: 1-866-225-0709
Email: info@hc-sc.gc.ca