Viral Infections

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Numerous viruses can infect mice and rats.  Only a few of the

most important viral infections among them will be discussed.



SENDAI VIRUS INFECTION:  In many mouse colonies, Sendai virus

infection is the most significant and serious respiratory

disease.  It often complicates chronic murine pneumonia,

increasing the death rate.  This virus is very unlikely to infect

pet mice unless they were acquired from a colony with this

infection already established within its members.



Nursing mice and those being weaned are the most commonly and

seriously infected.  Adult mice may become infected but rarely

show signs.  Signs of the infection include labored breathing,

rough haircoat, weight loss and death.  Bacterial infections

complicate the picture and usually increase the death rate.



There is no specific treatment for this disease.  A commercial

vaccine is available, but it is only of practical use with large

colonies of susceptible mice.



SIALODACRYOADENITIS:  Sialodacryoadenitis is a highly contagious

viral disease of rats and recently weaned mice.  Initial signs

include squinting, blinking and rubbing of the eyes.  Later,

sneezing and swelling in the neck region are noted.  As the

disease progresses, swellings below or around one or both eyes,

bulging of the eyes, red-brown tears, and self-trauma to the

eyes are noted.  Respiratory signs also may occur.



There is no specific treatment for this viral disease.  This

virus is very unlikely to infect pet rats and mice unless they

were acquired from a colony with this infection already

established within its members.



MOUSEPOX (Ectromelia):  Mousepox is a highly contagious viral

disease of mice that was only recently recognized in the United

States.  The mouse is the only natural host of the virus.



The acute (sudden onset) form of the disease affects the entire

body.  Clinical signs include lethargy, hunched posture, rough

haircoat, diarrhea, inflammation of the eye membranes,

swelling of the face and legs, and death.  Another form of the

disease results in a body-wide skin rash.  Soon, the skin

becomes swollen and ulcerated.  Because of the resulting pain and

discomfort, afflicted mice begin to chew on themselves.  This

behavior often becomes obsessive, resulting in amputation of

appendages.



There is no specific treatment for this viral disease.  This

virus is very unlikely to infect pet mice unless they were

acquired from a colony with this infection already established

within it members.