My mouse has a sore and big belly. Is it from fighting or illness?

First of all, Maizy looks more like a rat in the picture, unless she is an extremely large mouse. the lesions looks like a wound at the moment, but if it started as a lump it could be an abscess or a tumor. you will have to take her to an exotic vet specialist to get this checked and treated, if it is an infection she will need a course of antibiotics in order to heal properly.

Thank you for your question. If this bump is only on one side of the abdomen I would be concerned about a tumor or an abscess (pocket of infection). With a pregnancy we would expect a symmetrical swelling of the belly. I would recommend your friend take the mouse to a vet who sees pocket pets for an examination to better determine the cause of the enlargement.

Thanks for reaching out. Scratching to the point of bleeding and wounds, is likely fur mites, which are difficult to see with the naked eye. A veterinary visit is recommended to take a skin scraping and examine under the microscope. If positive, both mice need to be treated. Good luck.

The main stay of treatment is to keep the wound clean and dry. Make sure the bedding is cleaned regularly. With rodents, I recommend a dust free bedding called Carefresh. Rodents are very sensitive to dust in the environment. Also make sure that you are feeding a balanced diet approved for rodents and supplementing with healthy fruits and vegetables. Especially the leafy greens. Most healthy animals will be able to heal wounds on their own. Watch it every day for redness, swelling or discharge. If your mouse begins to lick at it too much, you may need to create a small cone to keep her from doing that. This is not generally a problem however. If it gets infected, there are veterinarians who treat rodents and this will generally resolve with antibiotics. I hope this is helpful and please feel free to post any additional questions.

Thanks for reaching out about Peanut and including photos. If she has dead fetuses in the uterus, there is nothing you can do at home and a veterinary visit is needed ASAP. Try to encourage her to accept food and water via a syringe. Provide a quiet and warm environment, separated from other mice. Good luck.

Thank you for using Petco Pet Education Center, formerly Petcoach! The condition you are describing sounds a lot like ulcerative dermatitis, a condition that is very common in mice, though the cause is unknown. The condition is characterized by very itchy wounds that form crusts, but unfortunately the cause is unknown. It may be caused by stress or an autoimmune disorder, but these are merely theories. Fortunately, the wounds often heal on their own - you can trim the hind nails carefully and apply SSD (silver sulfadiazene) ointment to the area twice a day. If the wounds become severe or very deep, you may need to seek veterinary care for pain medication.

Thank you for using Petco Pet Education Center, formerly Petcoach! That particular type of mouse does not have a cheek pouch - the only mice that do have cheek pouches are deer mice (these are brown, and have a little bit more hair on the tail). This swelling can be a mass, or swelling of the lymph nodes or salivary glands which are located in that region. This can be due to a viral infection, which is very contagious. I recommend separating the mice with swellings from the mice without them as soon as possible to avoid spread of any infectious agents. The sick mice should be seen by a vet, who can prescribe antibiotic medications and supportive treatments depending on the cause. If this is caused by a virus, the affected mice may shed the virus for the rest of their lives and require life-long care and separation. I hope this helps!