Salmonellosis at a glance
About: Salmonellosis is a bacterial infection which can infect cats, wild animals, birds, fish, and humans.
Transmission: Hunting, eating contaminated food or objects.
Symptoms: Diarrhea, vomiting, dehydration, weight loss and anorexia (loss of appetite).
Treatment: Supportive such as a bland diet to the gastrointestinal tract and fluids to maintain hydration.
Salmonellosis is a bacterial infection caused by the Salmonella bacterium. It is a common cause of enteritis (inflammation of the intestines) with associated vomiting and diarrhea. Salmonella can affect a wide range of animals, including humans, wild animals, domestic pets, farm animals, birds, fish, reptiles, and amphibians.
There are almost 2,000 serotypes of the genus Salmonella which live in the intestinal tracts of the infected host. Salmonella is rare in cats; however, it is of particular importance because it is a zoonotic disease, which means one that cats can transmit to humans.
The geographical distribution is worldwide.
Did you know?
Salmonella acquired its name from US veterinarian Dr Daniel Elmer Salmon, which was named in his honour by an assistant, Theobold Smith who first discovered it in 1885.
Not only did Dr Salmon give his name to the bacteria, but he was also awarded the first doctorate of veterinary science in the United States.
Clinical features of salmonella
Salmonellosis causes a reddening of the intestinal mucosa as well as reddening of the mesenteric (membranous sheet attaching various organs to the body wall, especially the peritoneal fold attaching the intestine to the dorsal body wall) and the lymph nodes. At this point, the body’s defences either contain the bacteria and its toxins or it invades the bloodstream (bacteremia) and then onto other organs such as the liver and spleen.
It can cause abortion in pregnant females.
Cats are most commonly infected via contaminated food or catching infected animals. Salmonellosis in cats is also known as songbird fever due to its association with cats acquiring infection from hunting and consuming birds.
- Salmonella can be found in feces and the saliva of an infected host. Cats become infected from catching and eating infected prey.
- Consumption of contaminated food (including raw meat, commercial cat food, and eggs) and water.
- Salmonella can survive on objects (food bowls, toys, etc.) for long periods.
Most infected cats will be asymptomatic (subclinical carrier state).
Salmonellosis is rare in cats; they are thought to have a natural immunity to the bacteria. Risk factors which can make a cat more susceptible to salmonellosis include the strain of salmonella (some are more pathogenic than others), cats in high-stress situations and environments such as shelters, immunocompromised cats, general poor health status, hospitalised animals, young and old cats.
Kittens, senior cats, and cats, with weak immune systems are more likely to develop clinical signs.
Symptoms of salmonellosis appear after 2 – 4 days of exposure and can include:
- Diarrhea (may or may not contain blood or mucus)
- Poor appetite (anorexia)
- High fever
- Abdominal pain
- Weight loss
The veterinarian will perform a complete physical examination of your cat and obtain a medical history from you, including recent food your cat has consumed as well as a history of hunting.
- Bacterial cultures from rectal swabs or fresh feces.
- Blood culture to isolate the bacteria if bacteremia.
- Biochemical profile, complete blood count, and urinalysis to evaluate the overall health as well as check organ function and determine how dehydrated your cat is. Most blood values return back normal, although reduced white blood cell count or anemia may be present in severely affected cats.
Supportive care at home for mild cases which may include a bland diet or restrict food for 24-48 hours.
- Symptomatic cats will receive fluids to treat dehydration and replace electrolytes.
- Blood transfusion for severe cases where septic salmonella has developed.
- It seems there is some controversy over the use of antibiotics to treat simple cases of salmonella enteritis (intestinal inflammation) with diarrhea in cats, suggesting that antibiotics can favour the growth of antibiotic-resistant strains of salmonella. Antibiotics (sulfa) are therefore reserved for severely ill cats.
Cats have been found to shed the serotype of salmonella, which is pathogenic to humans. However, there are very few (if any) reports of human infection from cats. There is a much, much greater risk of becoming infected via infected food.
When the cat grooms, bacteria in the saliva transfer onto the coat which can contaminate the environment. Take care handling a cat with salmonella as well and decontaminate the environment.
Reducing the risk of salmonella infection:
- Wash your cat’s food bowls after every meal. If you have more than one cat feed separately and avoid them sharing water bowls.
- Wash your hands after handling your cat.
- Wear rubber gloves when cleaning out litter trays.
- When emptying litter trays, clean with bleach and hot water. Rinse well.
- Young children, seniors and people with a compromised immune system are at particular risk and should avoid any contact with a cat who is recovering from salmonella.
- Keep your cat’s food and water bowls separate from utensils which will be used for people. They should have their own bowls and sponge to clean the bowls with.
- Remove uneaten wet cat food after 20-30 minutes.
- Bleach is the best method to kill salmonella bacteria in the environment at a ratio of 1:32. Clean surfaces before application of bleach as organic matter deactivates it.
- Leave the bleach solution on surfaces for a minimum of 10 minutes. Rinse thoroughly with clean, fresh water after contact with bleach and dry well.
- Administer all medications as prescribed.
- Follow-up appointments will be necessary to perform fecal cultures.
- Your veterinarian may recommend an easy to digest, low-fat diet while your cat is recovering. Chicken breast poached in water is highly palatable to cats and is easy on their gastrointestinal tract.