African pygmy mouse

Hypothermia

SignsSluggish, curled up without shivering, cold to the touch, barely responds when called

PreventionKeep the room at 24–28°C. In winter use an under-tank heater to create a temperature gradient and prevent night-time chill

Dehydration

SignsSunken eyes, slow skin tenting, scant dark urine, listless

PreventionCheck the bottle flow with a finger every day. Offer vegetables for moisture. Set the bottle at body height

Respiratory infection

SignsClicking or popping breathing sounds, nasal discharge, squinting, puffed-up fur

PreventionAvoid dusty bedding and urine ammonia; clean at least weekly. Minimize temperature swings

Diarrhea / enteritis

SignsSoiled tail base, soft or watery stool, poor appetite, sudden weight loss

PreventionGive fresh vegetables in small amounts and remove leftovers the same day. Do not change the diet suddenly

Skin disease / mites

SignsHair loss, scabs, intense itching, thickened skin on ears or face

PreventionUse clean bedding; quarantine newcomers in a separate cage for 2 weeks

Tumors

SignsLump on the body, rapidly growing swelling, one-sided abdominal distension

PreventionHard to prevent. Weigh weekly and check the body surface for early detection; consult a vet

Fractures (limbs, tail)

PreventionRemove mesh floors and wheel gaps. Keep the cage low, with soft bedding to cushion falls

First aidDo not touch; move to a small box and keep warm. No splints. Dragging a leg or a drooping tail means a same-day vet visit

Bites from cage mates

PreventionKeep groups same-sex or neutered. Quarantine newcomers before introducing. Provide more hides than animals

First aidPress bleeding gently with clean gauze. Move the injured animal to a separate cage. See a vet if the wound swells

Tail skin degloving

PreventionNever lift by the tail. Catch by guiding into a cup and moving it

First aidDegloved skin will not regrow. Press lightly to stop bleeding and see a vet the same day to prevent infection

Crushing / pinching

PreventionCheck cage doors, hide lids and bottle gaps. Never grip by hand

First aidCheck for breathing and rest in a dark, warm box. Internal bleeding is invisible, so see a vet the same day

Salmonellosis

RouteOral infection from hands that touched feces

PreventionWash hands with soap after care. Do not wash cage items in the kitchen

Dermatophytosis (ringworm)

RouteContact with hairless patches or bedding

PreventionHandle animals with hair loss using gloves and disinfect tools. See a doctor for ring-shaped rashes on your skin

Leptospirosis

RouteSkin contact with urine-contaminated bedding or water

PreventionWear gloves when cleaning. Do not touch bedding with cut hands. Do not leave urine sitting

Hantavirus infection

RouteInhaling droppings of wild rodents (rare in Japan)

PreventionDo not bring in wild animals. Dampen dry droppings before sweeping

Food

• Mouse pellets daily as the staple. Sunflower seeds: a few per week at most
• A small amount of finch seed mix. Insects (mealworms) once or twice a week
• 1–2 g per animal per day. Remove leftovers the next day and adjust the amount

Water

• Small bottle drinker. Change water daily at a height the nose can reach
• No deep dishes (drowning risk). A shallow lid with a little water is fine

Toys & play

• Small enclosed solid-surface wheel (about 12 cm diameter)
• Climbing structures such as paper tubes, cork tubes and twigs
• A shallow dish of pebbles or sand for bathing (mimics wild behavior)

Nest, bed & hideout

• Wooden or ceramic hides with small entrances, more than the number of animals
• Let them carry tissue or hay and build their own nest

Bedding & litter

• Paper bedding or aspen at least 5 cm deep for burrowing
• Avoid softwood shavings and cotton-type nesting (respiratory risk, entanglement)
• They do not litter-train; replace everything weekly and soiled corners daily

Cage / housing material

Glass tank or acrylic case with a fine-mesh wire lid (mesh 2 mm or less)

Size & space

At least 45 cm wide for a group of 3–5. Floor area and burrowing depth matter more than height

Layout

• Deep bedding, with hides, wheel and feeding spots spread out
• Fix the bottle where it stays reachable even after digging
• Inspect wiring and lid gaps from the inside; leave no climbing route

Placement notes

• Quiet room away from direct sun, air-conditioner drafts and cold window areas
• Place out of reach of cats and dogs; the door must have a lock

Exercise, free-roam & walks

• No free-roaming. Once in a narrow gap it cannot be retrieved
• All exercise happens inside the cage, with climbing items and a wheel
• Observe quietly at night in dim light. Do not shine a flashlight directly

Temperature & humidity

Temperature24–28°C. Below 20°C there is a risk of hypothermia

Humidity40–60%. Avoid condensation and stuffiness

Summer & winter

• Summer: avoid direct sun, keep at 28°C or below. No direct air-conditioner draft
• Winter: under-tank heater beneath the case; insulating cover on cold nights

Nail trimming

No nail trimming needed. Twigs and ceramic hides wear them down naturally

Brushing, skin & coat care

No brushing needed. Provide a sand bath and let them groom themselves

Other care

Give wooden hides and twigs to chew to prevent overgrown teeth. Weigh weekly

Protection from predators

• Never let cats, dogs or ferrets into the same room. Always lock the lid
• Use screens and a fine-mesh lid against mosquitoes and gnats. No insecticides
• Avoid loud noise and vibration; keep away from windows where crows can be seen

Foreign-body ingestion

Cotton nesting, lint and plastic scraps get swallowed, causing intestinal blockage or entanglement. Nesting material: paper or hay only. Loss of appetite with a swollen belly means a same-day vet visit

Being stepped on

Set on the floor, it vanishes in seconds and gets stepped on or caught in door gaps. Never release on the floor. If you may have stepped on it, suspect internal bleeding even if it moves and see a vet the same day

Getting pinched

Gets pinched in lid seams, hide lids and wheel axles. Use an enclosed wheel and check gaps. If pinched, do not pull; remove the whole part

Falls

Even a fall of tens of centimeters can cause fractures or head injury. Never put it on your hand; move with a cup or tube. After a fall, rest in a dark box and see a vet the same day

Escape

Escapes through gaps of 2 mm or more. If it escapes, close off the room, put toilet-paper tubes and food on the floor, and wait in the dark and quiet. Never use rodenticide or glue traps

Safe release procedure

1. Stay still and silent; keep the biting animal low
2. Lower your hand over the cage or a box and wait for it to let go
3. If it will not let go, blow gently on it or slip a piece of paper between
4. Once released, do not chase; return it to the cage and darken it

After the release

Wash the wound under running water and disinfect. Swelling, fever or spreading redness: see a doctor. Let the animal rest quietly for a few hours

What to tell the vet & what to bring

Phone ahead to confirm they see small animals. Report weight, photos of stool and bedding, number of cage mates and time of last meal; bring in a warmed small box

Checking consciousness, breathing & heartbeat

• Rest a finger on the back and watch for breathing movement. Normal is about 150 per minute, very fast
• Touch a fingertip lightly to the chest to feel the heartbeat. Normal is over 500 per minute, too fast to count
• Poke gently to check response and whether it can hold posture. Compare body temperature by hand

Stopping bleeding

• Press the site gently with clean gauze and hold still for a few minutes
• For tail bleeding keep pressing; do not use bandages or styptic powder
• If it will not stop or is heavy, transport with the gauze in place

Transport

• Line a small ventilated box with tissue, darken it and carry quietly
• Hold a hot-water bottle against the outside of the box; avoid direct sun and air-conditioner drafts in the car