Salmonella in Dogs and Cats

Wild birds like this American goldfinch can contract and spread salmonellosis. Photo by N. Lewis, National Park Service.

In March and April 2021, outbreaks of Salmonella infection linked to wild songbirds, ground turkey, and small turtles were reported, and several brands of dog and cat food were recalled because of possible Salmonella contamination.[1,2]
 
Dogs and cats are at risk of illness from salmonellosis. However, healthy adult animals infected with these bacteria often become carriers with no symptoms. Salmonella are zoonotic—they spread between humans and other animals—so a major concern with Salmonella infection in animals is that it increases the risk for people.
 
Sources
Animal Carriers
Salmonella are spread through the feces of infected animals. These are some of the animals that carry Salmonella and expose people to infection:

• Reptiles and amphibians: turtles, lizards, frogs, etc
• Birds: poultry (chickens, ducks, turkeys, geese), wild songbirds, parrots, etc
• Small mammals: mice, rats, hamsters, etc
• Farm animals: cows, pigs, sheep, etc
• Horses
• Dogs
• Cats[3]

 
Contaminated Food and Water
People and animals are most often infected with Salmonella by eating food or drinking water contaminated with feces. Handling contaminated food is also a risk if you don’t wash your hands thoroughly afterward to avoid bringing the bacteria to your mouth. Potential sources of Salmonella infection in humans, dogs, and cats include the following:

• Raw meat
• Raw meat pet diets
• Pig ears
• Chew hooves
• Dog and cat treats
• Dry dog and cat food
• Vitamins and nutritional products for animals[3,4]

 
Environmental Sources
Animals carrying Salmonella shed the bacteria into their environment. Animals that seem completely healthy can be Salmonella carriers. It’s safest to assume that Salmonella are present anywhere an animal of a high-risk species spends time: reptile habitats, terrariums, aquariums, chicken coops, animal pens, and so forth. Bedding and water tanks or bowls (especially in reptile and amphibian habitats) can also be contaminated.
 
Bird Feeders and Birdbaths
Wild songbirds aren’t just Salmonella carriers; sometimes they get sick and die of Salmonella infection. The type of Salmonella that birds carry, S typhimurium, is contagious to people and other animals. Cats who hunt birds or hang out under bird feeders and birdbaths can be infected.
 
Symptoms
Many adult dogs and cats exposed to Salmonella don’t get sick but can still spread the bacteria. Puppies, kittens, stressed animals, immunosuppressed animals, and animals with other diseases are more likely to become ill with salmonellosis. Symptoms include lethargy, loss of appetite, vomiting, fever, and diarrhea. The infection can be fatal in fetuses and newborns.
 
Salmonellosis in cats infected by birds is called songbird fever. Symptoms are similar to salmonellosis in other animals: vomiting, bloody diarrhea, lethargy, and loss of appetite.
 
Treatment
As with most diseases, specific treatment depends on the individual animal’s needs. Salmonella can develop resistance to antibiotics, so animals with mild symptoms might be treated only with supportive measures. In some cases, the choice of antibiotic is based on results of culture and antimicrobial sensitivity tests.[5]
 
Prevention
Be aware that raw meat pet diets are a common source of Salmonella. The CDC recommends these measures to prevent Salmonella infections:

• Wash hands with soap and water after handling animals, pet food and supplies, bird feeders and birdbaths, and animal feces (even through a plastic bag) and before eating or drinking.
• Clean and disinfect surfaces that have been in contact with animals.
• Clean terrariums and aquariums outdoors, if possible. If you clean one of these items indoors in a tub or sink, disinfect the tub or sink afterward.
• Children under 6 years of age, older people, and people with compromised immunity shouldn’t handle animals that might spread Salmonella (especially reptiles, amphibians, and poultry) or help clean areas where these animals have been. At-risk adults who need to clean animal habitats should wear disposable gloves.
• Don’t eat or drink around animals that might spread Salmonella.
• Keep animals out of food storage and preparation areas.
• Clean and disinfect bird feeders and birdbaths regularly.
• Don’t touch a wild bird with your bare hands.
• Keep pets away from bird feeders and birdbaths.
• If a sick or dead bird is in your yard, remove your bird feeder and birdbath for 2 weeks.
• Contact your state wildlife agency if you find a sick or dead bird. (North Carolina Wildlife Resources Commission: https://www.nc.gov/agency/wildlife-resources-commission)
• If you need to dispose of a dead bird, handle it only with disposable gloves or with a plastic bag over your hand. Place the bird a plastic bag, tie the bag, and throw it away; then wash your hands.[3,6]

 
References
1. Reports of selected Salmonella outbreak investigations. Centers for Disease Control and Prevention. Accessed April 20, 2021. https://www.cdc.gov/salmonella/outbreaks.html
2. Recalls, market withdrawals, & safety alerts. US Food & Drug Administration. Accessed April 20, 2021. https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts
3. Salmonella infection. Centers for Disease Control and Prevention. Accessed April 20, 2021. https://www.cdc.gov/healthypets/diseases/salmonella.html
4. Kukanich KS. Update on Salmonella spp contamination of pet food, treats, and nutritional products and safe feeding recommendations. J Am Vet Med Assoc. 2011;238(11):1430-1434. doi:10.2460/javma.238.11.1430
5. Marks SL, Rankin SC, Byrne BA, Weese JS. Enteropathogenic bacteria in dogs and cats: diagnosis, epidemiology, treatment, and control. J Vet Intern Med. 2011;25(6):1195-1208. doi:10.1111/j.1939-1676.2011.00821.x
6. Salmonella outbreak linked to wild songbirds. Centers for Disease Control and Prevention. April 1, 2021. Accessed April 20, 2021. https://www.cdc.gov/salmonella/typhimurium-04-21/index.html
 
Image source: Shenandoah National Park (photo by N. Lewis, NPS)

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