Understanding Salmonella infections in dogs, and what veterinary professionals and dog owners need to know
Salmonella is a genus of bacteria that is commonly associated with foodborne illnesses in humans- BUT, did you know it also poses a significant health risk to dogs. In today’s blog, let’s talk about what Salmonella is- including the different types of Salmonella species- as a way to understand the complexities of Salmonella infections and protect their canine companions from this potentially serious pathogen!
What is Salmonella?
Salmonella is a Gram-negative, rod-shaped bacterium belonging to the family Enterobacteriaceae. It is widely distributed in the environment and can be found in the intestinal tracts of animals and humans. While more than 2,500 serotypes of Salmonella have been identified, not all are pathogenic to dogs. The most common species implicated in canine infections is Salmonella enterica, which is further divided into multiple serotypes, including Salmonella Typhimurium and Salmonella Enteritidis.
Salmonella Species Types in Dogs
While Salmonella enterica is the main pathogenic species, affecting both humans and dogs with a range of serovars causing gastrointestinal illness, dogs can be infected by various Salmonella species types, with the following being the most commonly reported:
- Salmonella enterica is a broad species that includes many serovars known for causing foodborne illnesses in humans, leading to diarrhea, fever, and abdominal cramps. In dogs, S. enterica can lead to gastrointestinal issues like vomiting, diarrhea, and abdominal pain. Dogs may get infected from contaminated food, water, or contact with infected animals.
- Salmonella koseri is less common but can cause infections, particularly in immunocompromised individuals. It may lead to gastrointestinal symptoms similar to other Salmonella infections. It can cause gastrointestinal upset in dogs, including symptoms like diarrhea and vomiting. It is less frequently reported compared to other Salmonella strains but still represents a risk.
- Salmonella bongori is also not as common and primarily affects reptiles and has been rarely reported in human infections. When it does infect humans, it can cause gastrointestinal symptoms similar to other Salmonella species. In dogs, S. bongori contributes to gastrointestinal symptoms such as diarrhea, vomiting, and abdominal pain. Infections in dogs are less frequent but can occur, particularly if they have close contact with reptiles or contaminated environments.
Types of Infections Caused by Salmonella in Dogs
The clinical manifestations of Salmonella infections in dogs can vary widely, ranging from asymptomatic carriage to severe, life-threatening illness. The types of infections that can occur include:
Gastroenteritis
- Symptoms: Diarrhea (which may be bloody), vomiting, abdominal pain, fever, and dehydration.
- Pathophysiology: Infection often occurs after ingestion of contaminated food, water, or contact with contaminated feces. The bacteria invade the intestinal mucosa, leading to inflammation and clinical signs of gastroenteritis.
Systemic and Localized Infections
- Symptoms: Fever, lethargy, anorexia, and in severe cases, septicemia and shock. Symptoms of localized infections include arthritis, pneumonia, or meningitis.
- Pathophysiology: These infections occur when *Salmonella* bacteria disseminate from the gastrointestinal tract to other parts of the body, leading to localized disease.
Asymptomatic carriage of Salmonella can be a problem!
It is possible that your pet dog may be carrying a Salmonella species without signs of infection. While they may not experience symptoms, they can shed the bacteria in its feces, posing a risk of transmission to other animals and humans. It is important to be aware of this fact- and even get your dog tested through your vet! This is because asymptomatic carriers are significant from a public health perspective as they can contribute to the spread of Salmonella within households and communities.
Public Health Considerations, Zoonotic Potential
Salmonella is a zoonotic pathogen, meaning it can be transmitted from dogs to humans. Proper hygiene, including handwashing after handling infected dogs or their feces, is crucial to prevent transmission.
Preventing Salmonella infections in dogs involves several strategies
- Proper Hygiene: Regular cleaning of food and water bowls, and prompt removal of feces can help reduce the risk of infection.
- Safe Food Practices: Avoid feeding raw diets or undercooked meat to dogs, as these are common sources of Salmonella.
- Minimize Exposure: Keep dogs away from areas where they might encounter contaminated environments, such as farms with livestock or stagnant water sources.
Treating Salmonella Infections in Dogs
The treatment of Salmonella infections in dogs depends on the severity of the infection and the health status of the animal. Here are the main approaches:
- Fluid Therapy: Rehydration is critical, especially in cases of gastroenteritis, to manage dehydration and electrolyte imbalances.
- Nutritional Support: Dogs may require a bland diet or temporary withholding of food to rest the gastrointestinal tract during acute illness.
- Probiotics may be recommended to help restore the normal gut flora, particularly after antibiotic therapy. They can aid in the recovery process and reduce the duration of diarrhea.
- Antibiotic Therapy: Antibiotics are typically reserved for severe infections, such as systemic salmonellosis, or in cases where the dog is at high risk of complications (e.g., young puppies, elderly dogs, or immunocompromised animals). Commonly used antibiotics include:
– Amoxicillin
– Enrofloxacin
– trimethoprim-sulfamethoxazole.
Using Next-Generation Sequencing as a Diagnostic Tool to Treat Salmonella Infection
While antibiotic therapy must be guided by culture and sensitivity testing to avoid the development of antibiotic resistance, there are more effective ways to test for AMRs and provide better treatment for your pup- like Next-Generation Sequence testing (NGS) has become well-known to be a powerful diagnostic tool with higher sensitivity and specificity to not only detect various Salmonella pathogens, but that can assess a comprehensive list of AMRs present in your pup!
NGS can simultaneously identify multiple pathogens, which is particularly useful in cases where pathogenic infection is suspected that may be in lower abundance or cannot be detected using culture or PCR testing.
The use of NGS in veterinary diagnostics has become very popular for these reasons!
Several commercial laboratories offer NGS-based testing for Salmonella infections that veterinarians should consider. MiDOG can run NGS testing for Salmonella infections in dogs in a quick turnaround time (roughly 2-3 days!) to allow for vets to provide a rapid diagnosis and treatment for our pups.
We can help you with this type of testing, check it out HERE!
Conclusion
Salmonella infections in dogs are a serious concern for both veterinary professionals and dog owners. Understanding the various *Salmonella* species that can infect dogs, the types of infections that can occur, and the best treatment practices is essential for managing and preventing this disease. By staying informed and vigilant, we can protect our canine companions from the risks posed by Salmonella and ensure their health and well-being.
References
1. Schulz, B. S., Strauch, C., Mueller, R. S., Eichhorn, W., & Hartmann, K. (2008). Comparison of the prevalence of enteric viruses in healthy dogs and those with acute haemorrhagic diarrhoea by electron microscopy. The Journal of small animal practice, 49(2), 84–88. https://doi.org/10.1111/j.1748-5827.2007.00470.x
2. Galán-Relaño, Á., Valero Díaz, A., Huerta Lorenzo, B., Gómez-Gascón, L., Mena Rodríguez, M.ªÁ., Carrasco Jiménez, E., Pérez Rodríguez, F., & Astorga Márquez, R. J. (2023). Salmonella and Salmonellosis: An Update on Public Health Implications and Control Strategies. Animals : an open access journal from MDPI, 13(23), 3666. https://doi.org/10.3390/ani13233666
3. Botha, W. J., Schoeman, J. P., Marks, S. L., Whitehead, Z., & Annandale, C. H. (2018). Prevalence of Salmonella in juvenile dogs affected with parvoviral enteritis. Journal of the South African Veterinary Association, 89(0), e1–e6. https://doi.org/10.4102/jsava.v89i0.1731.
4. Grünberg, Walter. 2020. ‘Salmonellosis in Animals’, Merck Veterinary Manual. https://www.merckvetmanual.com/digestive-system/salmonellosis/salmonellosis-in-animals.
Categories: Antibiotic Resistance, Bacterial Infections, Dogs, Next-Gen DNA Sequencing Technology, Pet Health, Safety and Wellness, Pet Parents
