Dead Mice. A Health Hazard For Cats?


Cats are natural hunters and often kill and eat rodents like mice and rats. While this behavior is normal for cats, there are some health risks associated with eating mice and being exposed to mice droppings or bites. Mice can carry a variety of bacteria, viruses, parasites, and other pathogens that can make cats sick if they become infected.

It’s important for cat owners to understand the potential illnesses their cats face from contact with mice and how to keep their cats safe. This article provides an overview of the common rodent-related diseases in cats, how cats get infected, symptoms to watch for, diagnosis and treatment options, steps to prevent exposure, risk factors, and the prognosis for infected cats.

Diseases From Mice

Mice and other rodents can carry a number of diseases that they can transmit to cats who hunt or eat them. Some of the most common include:

In addition to these, mice can also potentially transmit hantavirus, tapeworms, and lymphocytic choriomeningitis virus (LCMV) to cats.

How Cats Get Infected

There are a few main ways cats can become infected or sick from mice:

Ingestion – If a cat eats an infected mouse, it can ingest pathogens directly. Common diseases spread this way include toxoplasmosis, roundworms, and viral diseases.

Bites and Scratches – If an infected mouse bites or scratches a cat, diseases can be transmitted that way. This includes bacterial infections and rat bite fever.

Contact – Simply coming into contact with an infected mouse or their droppings/urine can transfer diseases to cats. These include leptospirosis and salmonellosis.

Inhalation – Some rodent diseases like hantavirus can become aerosolized and infect cats through inhalation.


Cats infected with diseases from mice can show a variety of symptoms, including:

  • Lethargy and generally acting sick1
  • Gastrointestinal problems like vomiting and diarrhea1, 2
  • Respiratory issues like nasal discharge, sneezing, or coughing1
  • Mouth lesions1
  • Weight loss2

If a cat ate a mouse, watch for signs of illness like vomiting, diarrhea, or abdominal pain in the 24-48 hours after ingestion.3


There are several methods vets use to diagnose mouse-related diseases in cats:

Physical exam – The vet will check for signs of illness like fever, lethargy, vomiting, diarrhea, etc. They will also check the mouth, skin and coat for abnormalities.

Blood tests – Blood tests can check for anemia, signs of infection, and liver or kidney issues which may indicate disease. Specific blood tests can also check for toxoplasmosis antibodies.

Fecal tests – Fecal samples can be tested for parasites like Toxoplasma gondii eggs.

Urinalysis – A urine sample may show kidney problems or other abnormalities.

Biopsies – The vet may take tissue samples from organs like the liver or lymph nodes to check for disease under a microscope.

Imaging – X-rays, ultrasounds or CT scans can reveal abnormalities in organs that may indicate illness.

Cerebrospinal fluid analysis – For neurological symptoms, a CSF sample may be taken to check for infection.

If poisoning is suspected, tests can check blood clotting function and look for rodenticides. According to the ASPCA, “most cases of poisoning are diagnosed in pets that have signs of bleeding and a known or suspected exposure to anticoagulant rodenticides.”1


If a cat becomes sick after ingesting an infected rodent, treatment will focus on addressing the specific infection and providing supportive care. Here are some common treatments:

Medications: Antibiotics like doxycycline may be prescribed to treat bacterial infections like leptospirosis. Anti-parasitic drugs like fenbendazole can help clear intestinal parasites. Supportive medications like anti-nausea drugs may also be used.

Supportive care: Fluids and nutritional support may be needed for cats dealing with vomiting or diarrhea. Hospitalization in severe cases may help provide intensive nursing care. Any abnormalities impacting organ function will also need to be managed.

With prompt veterinary treatment, most cats can recover fully after becoming ill from eating mice. However, certain infections like hantavirus can potentially be fatal. Prevention through rodent control is key to keeping cats safe.


There are several steps cat owners can take to help prevent their cats from getting sick after interacting with mice or eating them. The most important is keeping mice out of the home and away from cats in the first place. This involves sealing up any entry points into the home, keeping food in sealed containers, cleaning up any crumbs or food debris, and using humane traps to catch any mice already in the home (Rodent Illnesses in Cats).

Vaccinating cats against diseases carried by rodents is also recommended. There are vaccines available for leptospirosis, panleukopenia, and rabies – all illnesses cats can contract from mice (Put A “Paws” On Hunting: Keep Your Cat Safe From Rodent …). Keeping cats up-to-date on these important vaccinations provides immunity against many rodent-carried diseases.

In addition, keeping cats indoors helps prevent hunting and interacting with mice and other rodents. Providing mental stimulation indoors through interactive toys and playtime can curb a cat’s desire to hunt. Using deterrents like cat bibs may also discourage successful hunting. Keeping litter boxes clean and food and water bowls filled will help prevent cats from venturing outside in search of bathroom spots or food sources.

Risk Factors

Certain conditions can increase a cat’s risk of becoming infected with diseases from mice and other rodents:

  • Outdoor access – Cats that go outside are more likely to hunt and consume prey like mice, exposing them to any diseases the rodents may carry.
  • Mousers – Cats with strong hunting instincts or that are encouraged to hunt rodents have a higher risk of encountering infected mice.
  • Exposure to rodent droppings and urine – Cats that are around areas contaminated with mouse feces and urine can become infected through grooming.
  • Ingesting rodenticides – Consuming poisoned rodents can directly transmit toxins like anticoagulant rat poisons to cats.
  • Living in rural areas – Higher rodent populations in rural settings increase exposure risk.
  • Eating raw meat diets – Consuming raw, uncooked meat may contain parasitic organisms or plague bacteria if contaminated rodent parts are present.

Veterinarians recommend keeping cats indoors and supervising any outdoor access to limit hunting. Promptly cleaning any rodent droppings or carcasses can also lower infection risks. Cats with potential exposure should be routinely screened and monitored for signs of illness.


The prognosis for cats that contract illnesses from mice or other rodents depends greatly on how quickly treatment is started. According to The Spruce Pets, with swift veterinary care, most cats can recover fully from rodent-borne diseases. However, the chances of survival decrease the longer it takes to get treatment. That’s why it’s critical for cat owners to watch for any symptoms after a cat eats or kills a mouse and get their pet checked by a vet right away if they have concerns.

Certain illnesses like leptospirosis have a good prognosis if treated early. With proper antibiotics, hydration therapy, and supportive care, most cats can recover within a few days to a week. More serious diseases like rat bite fever have a guarded prognosis even with treatment. According to a Texas A&M veterinarian, the mortality rate for untreated rat bite fever can be as high as 13% in humans and is likely similar in cats.

Overall, diseases from mice and rats can make cats very sick. But with attentive cat owners, prompt veterinary care, and aggressive treatment, the prognosis for full recovery is often good. Preventing hunting and exposure is ideal, but prompt action at the first signs of illness in a cat that ate a mouse gives them the best chance of bouncing back.


In summary, while catching and eating dead mice does present some health risks to cats, the risks are relatively low if proper precautions are taken.

The main diseases to be aware of are toxoplasmosis and leptospirosis. Cats can contract toxoplasmosis by ingesting infected rodents, which can cause flu-like symptoms. Leptospirosis is less common but can also be transmitted by rodents and can lead to kidney or liver damage if untreated. Thankfully, most cats have strong immune systems and can fight off these infections naturally.

To prevent disease transmission from dead mice, it’s advisable to keep cats indoors and use rodent control methods to limit mice populations around the home. Veterinarians also recommend keeping cats up-to-date on vaccines and deworming to boost their immunity. Additionally, prompt treatment if any symptoms arise can greatly improve outcomes.

While the risks are low, cat owners should be vigilant and monitor their pets’ health closely if they are known to hunt mice frequently. With proper precautions, cats can safely indulge their natural hunting behaviors while avoiding any serious illness.

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