External Parasite Problems: 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. A veterinarian 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 a new injectable drug (ivermectin) that has proven very effective in treating mange in a wide range of animals.
Lice may also parasitize the haircoats of pet mice and rats. They are flattened, wingless insects that suck tissue fluids and blood from the skin of the host. Ace 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. The lice of mice and rats are found most often on the neck and body. They suck blood and can, therefore, cause anemia (sometimes death) and transmit bloodborne diseases to rodents. Louse infestations may also cause scratching, hair loss and skin wounds. A veterinarian should be consulted if louse infestation is suspected.
Intestinal Parasite Problems: 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. Stool examination should be conducted by a veterinarian to diagnose these parasitisms. Appropriate treatment will be recommended by the veterinarian. Pinworms are especially difficult (sometimes impossible) to eliminate from mice and rats. Transmission of these parasites to people is possible but unlikely. Therefore, great care should be (en when handling and disposing of rodent feces. Furthermore, contact between pet mice and rats, their feces, and young children should be limited and always supervised by adults.