Perhaps you’ve seen a mouse in your home, office, or when you were out and about recently. Maybe your kid just asked for a pet mouse. You may have started wondering, “Are mice dangerous? Do mice carry diseases? What diseases do mice carry? Can I get diseases from mice?” We’re here to answer all those questions.
First, mice can be dangerous. As with any animal, wild or domestic, a mouse might bite or scratch someone. Second, yes, mice carry diseases and humans can get diseases from mice. Below, we’ll delve into the diseases mice carry, whether the diseases are harmful, how a person and/or a pet could become infected, symptoms of the diseases, and how to treat them.
What Diseases Do Mice Carry?
Mice and rats carry over 35 different diseases worldwide. Of those, mice directly transmit hantavirus pulmonary syndrome, hemorrhagic fevers, leptospirosis, lymphocytic choriomeningitis, and salmonellosis. All of these diseases are harmful to people. Leptospirosis, lymphocytic choriomeningitis, and salmonellosis pose a danger to pets.
Mice also carry various bacteria, such as E. coli, Shigella, and Clostridium difficile, which are responsible for sometimes severe intestinal disorders.
Mice-Borne Disease Infections
Direct transmission of mice-borne diseases and bacteria is typically through touching an infected mouse, infected droppings, urine, or saliva, or being bitten. Some, like hantavirus, hemorrhagic fevers, and lymphocytic choriomeningitis can be contracted by inhaling contaminated dust.
Hantavirus Symptoms and Treatment
Hantavirus pulmonary syndrome (HPS) is a disorder of the respiratory system. It’s primarily transmitted by mice and other rodents that live in and around homes. Symptoms usually appear within 1-8 weeks of infection and include fatigue, fever, and muscle pain. In some cases, headaches, dizziness, chills, nausea, diarrhea, and abdominal pain are also early symptoms. About 4-10 days later, a cough develops, accompanied by shortness of breath because fluid is filling up the lungs. In 38% of cases, HPS is fatal.
While there is no cure for HPS, oxygen therapy in an intensive care unit is the most effective treatment.
Hemorrhagic Fever Symptoms and Treatment
Hemorrhagic fevers are groups of disorders primarily characterized by damage to multiple organ systems. One common group transmitted by mice is hemorrhagic fever with renal syndrome (HFRS). These diseases are caused by hantavirus. Between 1 and 8 weeks after infection, people experience severe head, back, and abdominal pain, as well as fever, chills, nausea, and blurry vision. Less common symptoms include flushing, eye inflammation, or rash. These symptoms are followed by low blood pressure, shock, internal bleeding, and kidney failure. While not as dangerous as HPS, HFRS causes death in 1-15% of cases.
HFRS treatment includes electrolyte and fluid management as well as blood pressure control and secondary infection treatment. Antiviral drugs are often administered. In some cases, dialysis is necessary.
Leptospirosis Symptoms and Treatment
Leptospirosis is a multi-system illness caused by bacteria. In humans, symptoms start between 2 days and 4 weeks after infection and include fever and chills, headache, muscle pain, nausea and vomiting, jaundice, abdominal pain and diarrhea, red eyes, and rash. However, some people with leptospirosis don’t show any symptoms. It can also come in phases. After the first phase, an infected person may recover and then relapse into a more serious second phase. People can be ill for a few days or more than 3 weeks with treatment. Without treatment, it can last several months.
Early treatment with antibiotics such as doxycycline or penicillin is necessary for efficient leptospirosis resolution.
In pets, leptospirosis is most common in dogs. As with humans, some infected animals don’t present any symptoms. However, others develop severe symptoms and the disease can be fatal. Symptoms in dogs include fever and shivering, sensitive muscles, lethargy, heightened thirst, urination changes, dehydration, vomiting and diarrhea, jaundice, disinterest in food, and eye inflammation. Leptospirosis can also be associated with liver and kidney failure as well as lung disease and internal bleeding.
There are vaccines for leptospirosis, which must be boosted annually. As in humans, antibiotics are used to treat infections.
Lymphocytic Choriomeningitis Symptoms and Treatment
Lymphocytic choriomeningitis is a house mouse disease. It’s caused by a virus transmitted by the house mouse (Mus musculus) and affects multiple systems. If symptoms are present, they typically begin 5-13 days after infection. First-stage symptoms include fever, fatigue, sore throat, appetite loss, muscle pain, sensitivity to light, and headache, as well as nausea and vomiting. Like leptospirosis, symptoms disappear before the second stage occurs, though not everyone experiences a second stage. Some fully recover after the first stage. In the second stage, fever and headaches recur, accompanied by neck stiffness, drowsiness, confusion, and even paralysis. It is rarely fatal but can cause abortion or birth defects in pregnant women.
In pets, it is most common in hamsters, mice, rats, rabbits, dogs, and pigs. As with humans, some infections are asymptotic. When experienced, symptoms are similar to those for humans, including appetite loss, fatigue, fever, and neurological problems.
Treatment for people and pets typically consists of addressing the symptoms, though antiviral drugs are administered in some cases.
Salmonellosis Symptoms and Treatment
Salmonellosis is caused by the Salmonella bacteria. While it’s typically considered a food-borne illness, mice can carry the bacteria and transmit it to humans and other animals. Symptoms typically manifest 12 hours to 3 days after exposure and include fever, diarrhea, stomach pain, nausea, and vomiting. Salmonellosis typically resolves without treatment after 4-7 days.
Pets that contract salmonellosis includes cats, dogs, and horses. Symptoms include fever, loss of appetite, lethargy, vomiting, and diarrhea.
Treatment includes antibiotics as well as fluid and electrolyte management.
Mouse diseases can be very harmful to both people and pets. The best treatment for mice-borne illness is preventing wild mice from getting into your home. Don’t leave food waste sitting around inside or just outside your home. It will attract mice. Seal any holes both inside and outside to make sure mice can’t get in. If you do find mice in your house, trap them and relocate or dispose of them.
If infected mice aren’t attracted to your home and can’t get in, they’re less likely to spread the disease to you, your family, and your pets.