Food Poisoning in Cats: Causes, Signs, and Treatment

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Most people have suffered from food poisoning at some point in their lives. In fact, many people can recall exactly how many times and exactly how or where they got food poisoning from. Food poisoning is not pleasant and it can happen to cats, too. Here, you’ll learn some causes of food poisoning in cats, signs to look for, and how it’s treated.

Causes of Food Poisoning in Cats

Cats can have pretty resilient stomachs. As natural carnivores, they have very acidic stomachs designed to break down and digest small rodents, birds, and other critters they like to hunt.

This makes them hardier and able to handle many viral and bacterial pathogens they may encounter in their diet.

However, even cats can get food poisoning under certain circumstances. When we’re talking about true food poisoning in cats, we’re usually talking about a couple types of very harmful bacteria.

We all need certain strains of bacteria in our gut to aid in healthy digestion and balance. Cats even have certain strains of Escherichia coli in their digestive tracts normally.

But if exposed to highly pathogenic strains of disease-causing bacteria, cats can get very sick.

There are a couple bacteria that can cause food poisoning:

• Escherichia coli
• Listeria monocytogenes
• Salmonella
• Campylobacter

1. Echerichia Coli

While E. coli might be found normally in a cat’s digestive tract, many foreign strains can be found in the environment. Some are more virulent or toxic, than others. E. coli can release something called an endotoxin, leading to severe intestinal inflammation.

2. Listeria Monocytogenes

Listeria is a bacteria that can survive for years in unfavorable environments, allowing it to persist in food production facilities. Listeria can persist even in properly refrigerated food and has been found in frozen raw beef.

3. Salmonella

Salmonellosis is one of the most serious food-borne illnesses. Although not considered a normal bacterial flora organism, some cats are asymptomatic carriers. Asymptomatic carriers can acquire and shed the bacteria in their stool but have no obvious signs of illness.

4. Campylobacter

Campylobacter is another bacteria found normally in the digestive tract of many cats. Campylobacter causes illness more often in cats less than 6 months old when their bodies are naive to the bacteria. Kittens kept in poor sanitary conditions, farm environments, or any environment where food and water contamination with stool can occur, are at highest risk.

How Do Cats Get Food Poisoning?

Contracting one or more of these disease-causing strains of bacteria can occur in a couple of ways:

• Preying on or eating small mammals, reptiles, or birds harboring these bacteria (especially Salmonella)
• Eating raw or rancid food items (often from household trash)
• Eating a raw food diet

With raw diets, the highest risk is associated with non-commercial raw meat and dairy products prepared at home. Most commercial raw diets are subject to food safety protocols and/or methods to reduce the risk of pathogenic bacterial presence.

Symptoms of Food Poisoning in Cats

Vomiting is just one of several signs you can see with food poisoning in cats. chie hidaka / Shutterstock.com

Signs and symptoms of poisoning related to food can be very similar regardless of what caused the food poisoning. The most common signs of food poisoning include:

• Vomiting
• Diarrhea (with or without blood)
• Poor appetite
• Fever
• Lethargy
• Stomach cramps or abdominal pain

Gastroenteritis, or inflammation of the stomach and intestinal tract can have similar signs, but a fever is uncommon. It can also have many causes. Even if caused by a dietary indiscretion or something your cat ingested, this is not considered the same as food poisoning. In comparison, food poisoning often has more severe, acute effects.

Complications of Food Poisoning

The bacteria involved with food poisoning can cause some specific complications. Some of these complications involve the bacteria leaving the GI tract and causing harm in other places in the body.

E. Coli

Virulent strains of E. coli can release endotoxin, causing severe gastrointestinal inflammation. E. coli causing enough gastrointestinal disease can leave the GI tract and enter the bloodstream, causing sepsis or septicemia (infection in the blood).

Salmonella

When Salmonella causes disease, some additional signs can include:

• Conjunctivitis (eye inflammation)
• Swollen lymph nodes
• Abortion or infertility in pregnant queens
• Sepsis or septic shock

Campylobacter

Campylobacter does not typically cause vomiting but an acute, watery to bloody diarrhea with straining. Because it occurs more often in very young cats and kittens, dehydration is a significant concern for their little bodies.

Other concerns Campylobacter can include swollen lymph nodes and high white blood cell counts.

Listeria

Listeriosis is rare in cats, but can have serious consequences when present. Some studies have found Listeria monocytogenes in up to 35% of raw chicken from retail grocery stores and up to 54% in raw pet food. Three cats that developed intestinal lymph node swelling in one 2019 study were found to have L. monocytogenes within the lymph nodes.

Other health concerns caused by Listeria include:

• Pregnancy loss and infertility in pregnant queens
• Muscle pain and muscle tremors
• Abnormal breathing
• Neurologic effects (facial nerve paralysis, head tilt, seizures)

Zoonosis Risk

One complication of food poisoning in cats is the risk that one or more of the disease-causing bacteria responsible might pass to humans in the home and cause illness. When a disease can be transferred from animal to human or vice versa, this is called a zoonotic disease, or zoonosis.

All four bacteria we’ve discussed are a zoonotic risk for people. It is possible to develop illness if anything contaminated with stool is handled. People can also contract foodborne illness from these bacteria from ingesting or handling raw or undercooked food themselves.

People are also at risk for contracting foodborne illness when handling raw meat, poultry, or dairy products to prepare for their cat.

Some cats, especially those hunting outdoors or being fed raw food diets, might shed disease-causing bacteria in the stool without showing any outward signs. Risk can be increased for humans in the home in these cases, especially those with compromised immune systems.

In any case where food poisoning is suspected in your cat, always contact your own health care provider if you develop any similar symptoms yourself.

Diagnosing Food Poisoning in Cats

Collecting a fecal sample to be analyzed is one way of testing for disease-causing bacteria. Oleg Opryshko / Shutterstock.com

Diagnosing food poisoning in cats can be tricky. It requires the right combination of accurate patient history, active symptoms, and supportive testing. Some relevant history information includes:

• Dietary history
• History of eating a raw diet
• Whether a cat is indoor or goes outdoors
• Whether a cat is prone to outdoor hunting/predation
• History of getting into the trash
• History of any other access to raw or rancid food

Cats often come to the veterinarian for signs of vomiting and/or diarrhea, but with food poisoning, some of the following findings are also likely be present:

• Acute onset of severe digestive upset
• Fever
• Abdominal pain
• Severe dehydration
• Very watery or bloody stool

Diagnostic testing must be considered and interpreted carefully but might include:

• CBC test: A complete blood count test might reveal high white cell counts from infection and low red blood cell counts from loss if blood is present in stool.
• Blood chemistry test: Might show low protein levels and can help rule out other causes.
• Fecal culture: This specifically looks for Salmonella, Campylobacter, or Listeria. E. coli is often cultured from the GI tract normally in cats so relevance might be hard to interpret.
• Fecal PCR: This test checks for molecular material, like DNA, for detection. Campylobacter and Salmonella might be detected with PCR, as well as other causes of diarrhea.
• Ultrasound: Might be used to look for signs of gastroenteritis and lymph node enlargement, and might help rule out other causes.
• X-rays: These are most helpful for looking for foreign material, but might be helpful to rule out other causes of symptoms.

A veterinarian will combine historical information, along with supportive exam findings and test results, to arrive at a diagnosis of food poisoning.

Treatments for Food Poisoning in Cats

Treatment for food poisoning depends on the severity of symptoms. Some cats affected more mildly might be treated on an outpatient basis with some medications given during an appointment and others sent home for further use. Some therapies include:

• Antiemetics (anti-vomiting medications)
• Anti-diarrheal medications
• Specific antibiotics (sometimes based on fecal culture if performed)
• Probiotics
• Subcutaneous fluids
• Pain medication
• Appetite stimulants

More severe cases of food poisoning might require hospitalized care. This is especially true if bacteria have migrated out of the GI tract and into the bloodstream causing septicemia. Because these cats are often not eating and severely dehydrated, injectable medications and therapies are used:

• Intravenous fluids
• Injectable antibiotics
• Injectable pain medication
• Parenteral nutrition (intravenous feeding tube)
• Enteral nutrition (nutrition through a nasogastric, esophagostomy tube, or percutaneous endoscopic gastrostomy tube)

Hospitalized cats often require more monitoring bloodwork or imaging with x-rays or ultrasound.

Cat Care Tips

The most important things to remember when managing a cat at home with food poisoning are:

• Continue all medications as prescribed by your vet (even if some signs or symptoms have improved or resolved)
• Monitor your cat’s appetite and litter box use very closely
• Keep all recheck appointments
• Alert your vet to any sudden changes in your cat’s condition (appetite change, lethargy)
• If your cat had a fever, find a method at home that will work best to monitor temperature. Ear thermometers are less accurate compared to rectal thermometers, but are easier to use for many cats.
• Small, frequent meals of highly digestible food is best for recovery.
• If your cat has known or suspected infection with potentially zoonotic strains of coli, Salmonella, Listeria, or Campylobacter, always adhere to strict hygiene practices for yourself or wear gloves when handling anything that could be contaminated with infected stool.

How To Prevent Food Poisoning in Cats

Feeding raw food can increase risk for foodborne illness in both cats and people. New Africa / Shutterstock.com

The following are the best ways to reduce the risk of food poisoning in cats:

• Keep cats indoors to reduce risk of outdoor exposure and predation
• Keep any raw or rancid food inaccessible in the home
• Make sure all trash bins have lids, can be locked, or cannot be easily knocked over
• Avoid feeding raw food, especially raw food prepared at home including raw eggs and meat. Any raw food purchased for human consumption carries a high risk of bacterial contamination and is not intended to be eaten without being cooked. Commercial raw diets still carry some risk. Always check to see what food safety protocols and measures are taken with specific brands.