Rodents are susceptible to skin disease which can be caused by numerous infectious agents, including bacteria, viruses, fungi and parasites. Cage mates may be responsible for hair loss and/or wounds to the skin.
Pet mice and rats may be infested with a variety of external parasites. Mites, nearly microscopic, spider-like organisms, live on the skin surface and feed primarily on skin debris. They are transmitted by direct contact between infested and uninfested rodents. Signs of infestation range from mild scratching to severe scratching, with hair loss and ulceration of the skin.
Your vet should be consulted if mite infestation is suspected. Microscopic examination of a scraping of the skin is necessary to confirm the diagnosis. Treatment may include an injectable drug that has proven very effective in treating mange in a wide range of animals.
Lice may also infest the haircoats of pet mice and rats. They are flattened, wingless insects that suck tissue fluids and blood from the skin of the host. Lice are larger than mites and can usually be seen without a magnifying lens. Lice are most often transmitted by direct contact with infested bedding and between infested and uninfested individuals. Lice are usually found on the neck and body. They suck blood and can, therefore, cause anaemia (sometimes death) and transmit blood borne diseases to rodents. Louse infestations may also cause scratching, hair loss and skin wounds. You should consult your vet if you think your pet might have a louse infestation.
Allergies are also a suspected cause of skin disease of pet rodents. In these cases, it is wise to replace the bedding being used with plain white, unscented paper towelling. You should consult your vet if you think your pet is exhibiting signs of skin disease. Your vet will need to conduct some diagnostic tests to find out what is the cause; they will then prescribe appropriate treatment based on the results of these tests.
Tapeworms and pinworms are the most common intestinal parasites of pet mice and rats. They often go undetected unless present in large numbers. Signs of infection may include weight loss, inactivity, inappetence, constipation, and excessive licking and chewing of the rectal area and base of the tail.
Your vet can perform a stool examination to diagnose these parasites, and they will be able to recommend appropriate treatment. Pinworms are especially difficult (sometimes impossible) to eliminate from mice and rats. Transmission of these parasites to people is also possible but unlikely. Therefore, great care should be taken when handling and disposing of rodent faeces. Furthermore, contact between pet mice and rats, their faeces, and young children should be limited and always supervised by adults.