Mouse health checks
You'll find it easier to spot when something's wrong if you're familiar with how your mice normally look and behave. Mice can become unwell and go downhill quickly, but may only show subtle signs of being in pain until it's very severe.
Mice find being caught and handled stressful, but it's important to check them regularly for their health and welfare. Always handle them carefully and considerately, in a confident but gentle manner. Make sure they can't fall or jump from a height in their home-cage, as they can hurt themselves or break limbs if they fall or are dropped from a height.
Mice can die if they lose 20 percent or more of their body weight, and in 30g mice this is only 6g. If mice are allowed unlimited food and are housed in surroundings that don't have enough interest, they can become obese. Consult a vet if your mouse loses fur or gains noticeable weight. Take your mouse to a vet immediately if they're showing signs of illness. Also remember:
- Regular vet checks - these will help spot problems early and help prevent disease.
- Keep poisonous materials – such as poisonous foods (including grapes or rhubarb), plants and chemicals – away from your mice. Contact your vet immediately if you're concerned they've come into contact with anything potentially harmful.
- Only use prescribed medicines - treat your mice only with the medicines prescribed for them by a vet. Human and other animal medicines are dangerous to mice.
- Suitable gnawing material will prevent their teeth growing too long and causing health problems and pain. Mice have specialised teeth for gnawing and their incisors grow continuously. Get a vet to check their teeth and ensure they're positioned and growing correctly.
- Watch for repetitive behaviour - barren environments, stress, frustration and/or lack of mental stimulation can lead to mice developing repetitive behaviours which signify poor welfare. Ask your vet for advice if you spot this.
Signs of illness
Mice can become unwell and go downhill very quickly, but may often only show subtle signs of being in pain or distress, or that they are suffering, until it is very severe. Take your mice to a vet immediately if they show any of the following signs:
- Not eating or drinking
- Hiding away from the other mice, more than usual
- Sitting in a hunched-up position
- Ruffled or ‘starry/spiky’ fur and/or a dirty, stained or dull coat
- Reddened or sore-looking skin
- Sunken or dull-looking eyes
- Discharge from their eyes or nose
- Losing weight, or quickly putting weight on
- Drinking lots
- Diarrhoea
- Urinating lots or not at all
- Chattering or clicking sound when they breathe
- Slow, irregular or fast breathing
- Very dark red or pale limbs, ears or nose
- Very hot or very cold limbs
- Head tilted
- Fitting, twitching, tremors or shivering
- Grating their teeth
- Difficulty walking, or unsteady balance
- Not using a limb
- Self-mutilation or gnawing at themselves
- Hot, swollen stomach
- Any injuries or abnormal lumps or bumps
Handling your mice
Always handle your mice carefully and considerately, in a confident but gentle manner. You can reduce the stress associated with handling by having positive interactions with your mice and allowing them to gradually habituate to you. Remember:
- Mice should be allowed to investigate your hands in their own time.
- If you need to momentarily restrain your mouse, always hold the mouse gently at the base of the tail as close to their bottom as you can and support their body, otherwise they could become injured. Do not restrain your mouse for any lengthy period of time as this can cause them distress.
- Never scruff or pick up a mouse by the tip of its tail, as this can be very distressing for them and can lead to injury. Instead try the cupping or tunnel techniques (explained below).
- Never lift them high above a surface, as they can be injured if they fall or jump.
Cupped hands technique
To pick up your mouse using the cupped hand technique, scoop them up with one or both open hands, and allow them to sit or walk over your hands without physically restraining them. If you find that your mouse attempts to escape by jumping off your hands, close your cupped hands loosely around them until their attempts to escape start to decrease (for a maximum of 30 seconds). You can then open your hands and allow them to sit or walk around on your hands unrestrained. This closed cupping shouldn’t be necessary after the first handling session.
Tunnel handling technique
A tunnel can be used in combination with the cupped hand technique. Gently guide them into a home-cage tunnel (one that’s usually available in their cage and has their cage scent on it), then allow them to crawl from the tunnel onto your cupped hands. If, the first time you handle your mouse they attempt to escape, close your hands loosely around the tunnel ends until their attempts start to decrease (for a maximum of 30 seconds). Then open your hands and allow them to crawl out of the tunnel onto your cupped hands. Covering the ends of the tunnel in this way shouldn’t be necessary after the first day or two of handling.
Transporting your mouse
Transporting your mice can be incredibly stressful for them – only do so if totally necessary. If you have to transport your mice, make sure you provide for all their needs and that you reduce the stress of transportation wherever possible.
- Use a suitable, secure pet cage.
- Make sure they have access to food and water. Food can be given as pellets, and to avoid spillages or flooding the cage, water can be given as pieces of apple, pear or potato (unless it’s a long journey).
- Give your mice bedding material for comfort, and place used, unsoiled nesting material in the transport cage.
- Transport any cage-mates that the mouse is usually housed with, with them. This not only helps to reduce the stress of transport, but can also help to reduce aggression when they get home.
- Make sure the transport cage has a cover to keep it dark. However, make sure air can pass in and out, for ventilation.
- Transport them in a quiet, air-conditioned car, rather than on public transport. Plan your route to minimise journey time and maintain suitable comfort and environmental conditions.
If you go away
If you're off on holiday, make sure you have someone responsible to care for your mice in their cage at your home. Avoid transporting your mice unless it's absolutely necessary.
Follow the links below to find out more about caring for your mice.
