Checking your mice for signs of illness

As mice are prey animals, they are good at hiding or living with any symptoms of illness that they may have. This makes it important that breeders keep a close eye on their stock and note any changes in condition or behaviour. Questions to ask yourself include:

• Does the mouse have a hunched up posture?
• Is it walking normally or is it "waddling"?
  
• Are its eyes bright? 
• Is the coat glossy and smooth? (not sticking up or separating) 
• Are any scabs or wounds visible? 
• Are any lumps present? 
• Is the mouse eating/drinking normally?
• Is it still grooming itself? 
• Is it less active than usual?
• Has the mouse’s skin taken on a pale or grey tone? 
• How are other mice treating it? (has it suddenly gone down in the hierarchy, are the others bullying it?) 

To do a quick physical exam, pick your mouse up as usual and let it sit on your palm. Take the base of the tail between your thumb and forefinger and lift the mouse up slightly so you can take a look at its rear. 

• Is the back end of the mouse free from dirt, debris and faeces? 
• Are there any swellings/lumps/wounds etc.? 
• Are there any protrusions from the anus or genitalia?
  

Whilst you are holding the mouse you will also be able to assess some other important physical signs. These include:

• Can you see evidence of mites? (look for tiny reddy brown dots that move)
• Has the mouse’s weight changed? (weight usually decreases with illness but not always)
• Is the mouse unusually inactive?
• Does the mouse seem cold? 
• Can the mouse hold itself upright/posture correctly? 
• Is the mouse able to walk around properly? 
• Does the mouse appear in pain, especially when lifted or touched in a certain place?

Checking your mice over will help to catch illnesses early. Mice have a fast metabolism and any illness can progress rapidly: your vigilance may mean the difference between any treatment you choose to give succeeding and failing.