Salmonellosis (Canine)

Salmonellosis is an infection caused by bacteria from the genus Salmonella. The infection is usually confined to the intestinal tract resulting in diarrhea, fever and abdominal cramping.

Salmonella in dogs can spread from the intestines to the blood and then to other organs, leading to severe illness. Although, disease from Salmonella spp is not common in dogs or cats, the disease can be transmitted to humans through contact with contaminated food and fecal material.

Common name: Food poisoning Scientific name: Salmonellosis

Salmonella in Dogs Signalment All dogs are susceptible to Salmonella infection, but the young and elderly are more likely to develop systemic infection. Dogs under stressful conditions (crowding, poor nutrition, and poor sanitation) may be more likely to become infected.

Salmonella in Dogs Incidence/prevalence In a single study conducted in north-central Colorado, 71 dogs with acute diarrhea were tested to see if the cause could be identified. In those with confirmed cause(s) for diarrhea, 2.3% were infected with a Salmonella species. Studies in working dogs such as sled dogs and racing greyhounds found incidence of Salmonella shed in 11-63% of fecal samples, with most dogs showing no signs of illness.

Salmonella in Dogs Geographic distribution Salmonella infections occur world wide.

Salmonella in Dogs Clinical signs (primarymost to least frequent, scientific term, synonyms) Diarrhea (+/- blood), abdominal cramping, fever.

Salmonella in Dogs Clinical signs (secondary most to least frequent, scientific term, synonyms) Anorexia or inappetence (poor appetite), dehydration (more fluids lost than taken in by drinking water).

Salmonella in Dogs Cause (scientific, common term) Many species of Salmonella, including S. enteriditis, can cause infections.

Organ system affected (most to least affected) Intestinal tract, blood, other organs (e.g. liver).

Diagnostic tests Fecal (or stool) culture, to isolate the bacteria. Specialized testing on positive cultures, to get the type. Examination for intestinal parasites that can cause similar signs.

Differential Diagnosis Parasites (intestinal worms), other bacterial infections (e.g. Clostridium), viral infections (e.g. parvovirus), Giardia or coccidian (one-celled parasites), food allergies.

Salmonellosis is a common bacterial infection of both mammals and reptiles. Though the most common site of infection is the intestinal tract, the bacteria often colonizes the lymph nodes that drain the intestines, so bacteria can be shed in the stools for months after the initial signs have resolved. Since dogs will eat carrion (dead animals) and fecal material of other dogs, they are frequently infected, whether they show signs or not.

Most common signs of Salmonella in Dogs are diarrhea that may contain mucous and blood, fever, lack of appetite and abdominal cramping. Infections can spread from the intestinal tract to the lymph nodes and then to other organs, resulting a more severe illness or even death.

Sources of Salmonella include stools from other dogs that are currently shedding the bacteria, contaminated natural pet treats (pig ears, rawhide chews) and raw pet food. In some cases meat not fit for human use is collected, ground, and frozen for later use. Mixing meat from a number of sources increases the risk for contamination to spread, and thawing at room temperature allows for additional growth of bacteria before feeding.

Dogs can transmit Salmonella to humans, especially to children or to anyone with a compromised immune system. Lack of hand washing after cleaning up stools, after pet care, before handling food, or before eating are the primary means of transmitting the bacteria to people.

Salmonella in Dogs Home Care At home care of diarrhea includes encouraging drinking of water, and feeding bland and easily digested food. If other signs develop, such as lethargy or weakness, if a dog starts to vomit, if the skin seems to be getting less flexible, or if the diarrhea lasts over 24 hours, smells very bad, or contains mucous and/or blood, it is time to seek veterinary care. Extra care should be taken in cleaning up stools and disinfecting areas exposed to infected feces to prevent transmission to other pets or to humans.

Salmonella in Dogs Professional Care Veterinarians can test for specific causes of diarrhea as well as for secondary problems such as dehydration. If a bacterial infection like salmonellosis is found, appropriate antibiotics are beneficial. Intravenous (IV) fluids replenish body fluids and other supportive care ton make the pet more comfortable. Special diets that are easily absorbed can help as well.

Salmonella in Dogs Action Salmonellosis generally responds to appropriate antibiotics and other supportive care. Veterinarians can assist in identifying the source of the infection. Common sources include chewing on dead animals, feeding raw or improperly processed meats, and contaminated dog treats/food made from animal tissue.

Salmonella in Dogs Outcome With prompt and appropriate treatment, dogs are likely to have a full resolution of their clinical signs. Regardless of treatment, a large percentage of dogs retain bacteria in the lymph nodes near the intestines and can shed bacteria for many weeks to months. With proper hygiene practices and environmental care the spread of the infection to other animals, and especially humans, can be prevented.

References/Additional Readings Cantor GH., et.al. Salmonella shedding in racing sled dogs. Journal of Veterinary Diagnostic Investigation 1997; 9:447, 448.

Chenagappa, MM, et al. Prevalence of Salmonella in raw meat used in diets of racing greyhounds Journal of Veterinary Diagnostic Investigation 1993; 5:372-377.

Finley, R et al. Human Health Implications of Salmonella-Contaminated Natural Pet Treats and Raw Pet Food. Food Safety CID 2006; 42: 686-691.

Hackett, T et al. Prevalence of Enteric Pathogens in Dogs of North-Central Colorado. Journal of the American Animal Hospital Association 2003; 39:52-56.

Hoskins, JD. Bacterial Infections. In: Morgan, RV, ed. Handbook of Small Animal Practice, 3rd Ed. Philadelphia: W.B. Saunders Company, 1997; 1148-1149.

Morse, EV et al. Canine Salmonellosis: A Review and Report of Dog to Child Transmission of Salmonella enteritidis. American Journal of Public Health 1976; 66:82-84.

Author Mary M Schell DVM, DABT, DABT

Editor Sharon Gwaltney-Brant DVM, PhD, DABVT, DABT