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Diseases Caused By Vermin

Mice and rats have lived parasitically with humans for thousands of years.  The amount of food that they have eaten or despoiled probably goes into the millions of tons.  However, the greatest threat posed by these vermin is their potential for spreading disease, and not only to us, but to our pets as well.  The mice most frequently found in homes are the house mouse and the deer mouse.  Rats ordinarily come in two varieties – the Norwegian rat and the black rat.  The latter is most famous for spreading bubonic plague and helping to cause the Black Death in Europe in the 13th and 14th centuries.  Although plague is uncommon in most parts of North America (it crops up periodically in the American Southwest), rodents can spread several other serious diseases.


It is a disgusting fact, but mice will produce about 80 droppings per day.  Basically, wherever they scamper, they will leave droppings.  They will also leave urine, which you probably will not be able to detect.  Both of these excretions can contain salmonella bacteria, and if you or your pet eats food so contaminated, you will suffer from this gastric illness.  Even if you throw out food that shows signs of rodents, you can also pick up the bacteria on your hands, and you can become ill from salmonella if you eat or drink before washing your hands.

Lyme Disease

This ailment is not caused by rodent droppings, but by the ticks that rodents, especially deer mice, carry.  Lyme disease is a serious illness that can cause fever, joint pain, and headache.  Sometimes, it can cause arthritis and damage to the heart.  Ticks must be attached to you for several days before you become infected, and often a red ring will form around the original bite.  However, sometimes the ring is not present, and if you exhibit any of the above symptoms after finding a tick on yourself, see a doctor immediately for antibiotic treatment.  Lyme disease has been linked with chronic fatigue syndrome, too.


Hantavirus is a serious, sometimes fatal disease spread by rodents.  This disease can be produced by contact with rodent feces or urine, but also by being bitten by an infected rat or mouse.  Hantavirus can cause serious lung infection or even kidney problems, and as it is a virus, will not be touched by antibiotics.  While many cases of Hantavirus are only thought to be flu, and pass through without doing serious harm, some will need hospitalization.  Fortunately, a significant proportion of the population appears to have immunity to this virus, especially those of European origin.

Rat Bite Fever

Rat bite fever is caused by one of two bacteria, so will be able to respond to antibiotic treatment.  It is caused, as its name suggests, usually by a rat bite, although it can also be caught by exposure to droppings or urine.  This illness causes fever, inflamed joints, rash, and even ulcerations near the bite site.  It can also cause headaches and vomiting.  In untreated, severe cases, it can cause heart damage.  Although the disease will usually run its course without treatment, there is the possibility of a rare fatality, and without antibiotics, it can take a year or more to be free of the symptoms.