Hedgehog Respiratory Infection and Pneumonia: The Early Signs

Quick answer

A healthy hedgehog breathes silently through its nose. Any repeated wet sound at rest is worth investigating.

Respiratory infection is one of the commonest reasons a pet hedgehog dies, and it is usually well established before the owner hears anything. Hedgehogs are small, nocturnal and secretive, and the early signs happen in the dark while you are asleep.

The first change is almost never a cough. It is a shorter night: less wheel running, a slower start to foraging, and a nose that looks slightly wet or crusted in the morning.

• Sneezing with a wet nose, then crusting around the nostrils, is the usual opening sequence.
• Clicking or popping made in your face when the hedgehog is disturbed is a defensive display. Clicking or bubbling that continues while the hedgehog is undisturbed is a respiratory sound.
• Open-mouth breathing, visible abdominal effort, or a hedgehog that will not unball and breathes hard is an emergency.
• Cold rooms, dusty or aromatic bedding, ammonia from soiled bedding and dry heated winter air are the four husbandry causes behind most cases.
• Almost all online information about hedgehog respiratory disease refers to wild European hedgehogs and lungworm. It does not apply to a pet African pygmy hedgehog.

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Never use human decongestants, vapour rubs, essential oils, eucalyptus, tea tree or a scented humidifier on a hedgehog.

A hedgehog has a small airway, a very small body and a nose it uses constantly. Aromatic oils are direct airway irritants and are absorbed through the skin. They make an inflamed airway worse and can cause collapse. The same applies to burning candles, incense, plug-in air fresheners and aerosol sprays in the room where the hedgehog lives.
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Why hedgehogs get chest infections so easily

An African pygmy hedgehog comes from warm, dry savannah. Kept in a European or North American home, it typically lives at the bottom of or below its species temperature range unless the enclosure is heated deliberately and thermostatically.

Temperature does two things at once. It drives immune function, so a persistently cool hedgehog defends itself badly against organisms it would normally contain. It also triggers the attempt to hibernate, and a hedgehog that goes torpid stops eating and drinking while bacteria carry on multiplying.

Then there is the air itself. A hedgehog spends its whole life with its nose in the bedding, pushing and digging. Whatever the bedding gives off, it inhales concentrated.

Wood shavings from pine or cedar release aromatic compounds that irritate the airway lining. Dusty paper or sawdust bedding does the same mechanically. Soiled bedding produces ammonia, which strips the protective mucus layer and paralyses the cilia that sweep debris out of the airway. Once that clearance mechanism is damaged, ordinary bacteria that were being handled quietly get a foothold.

Dry winter air from central heating thins the airway mucus further, which is why cases cluster after the heating goes on.

Staging: what it looks like early, established and late

Early.

A slightly wet nose in the morning. Occasional sneezing, often dismissed as dust. Wheel distance drops, or the hedgehog starts later and stops earlier. Appetite is still normal or nearly so.

This is the stage where treatment is straightforward and cheap, and it is the stage almost everybody misses, because nothing looks dramatic.

Established.

Crusting around the nostrils that reforms after you clean it. Audible clicking or bubbling on breathing when the hedgehog is not being handled. Appetite drops. Weight starts to fall. The hedgehog sleeps into the night and is reluctant to come out.

Some hedgehogs at this stage sit with the front end slightly raised, because it makes breathing easier.

Late.

Effort you can see: the flanks pumping, the whole body moving with each breath, a stretched neck, or breathing through an open mouth. Refusal to eat. Cold to the touch. A tight, unmovable ball that will not relax even when warm.

At this stage the animal is often also dehydrated and hypothermic, and the two together kill faster than the infection.

Foraging effort is an early measure. A hedgehog that stops working a puzzle feeder it used to empty is telling you something before any noise does.

What else makes these signs

Every sign here has look-alikes, and telling them apart changes what happens next.

The heart disease overlap deserves emphasis. Dilated cardiomyopathy is a well recognised problem in pet hedgehogs, and its early presentation is exactly what an owner reads as a chest infection: less activity, breathing that looks like effort, and weight loss. The difference is usually the nose, which stays clean, and the history, which is one of gradual decline rather than a sudden onset. Only radiographs and an ultrasound examination settle it, and treating heart failure as an infection wastes the time that matters.

The failure modes of the usual advice

"Hedgehogs get lungworm, so treat for parasites."

Lungworm is a disease of wild European hedgehogs, which eat slugs and snails. A pet African pygmy hedgehog eating a commercial diet and captive-bred insects is not exposed to that life cycle. Almost every rescue article an owner finds online is about a different species with a different problem. Treating for the wrong thing delays the right thing.

"Clicking is a happy hedgehog sound."

Hedgehogs do click and pop as a defensive display, and they huff when annoyed. Those noises are made at you. A wet click, crackle or bubble that repeats with each breath while the animal is asleep is a different sound with a different meaning. Record it on your phone; a vet can tell them apart instantly.

"Put it in a steamy bathroom to clear the airways."

Hedgehogs overheat easily and heat stress is its own emergency. Nebulisation prescribed by a vet is a controlled version of this idea; a hot bathroom is not.

"Switch to wood shavings, they are more absorbent."

Pine and cedar shavings are among the worst choices for an animal that buries its face in bedding. Kiln dried aspen, dust extracted paper bedding, or washed fleece liners are safer. If a bedding raises visible dust when you pour it, it is raising dust in the hedgehog's nose all night.

"Wait and see if it clears up."

Respiratory infection in a small mammal progresses to pneumonia. A hedgehog that stops eating is losing ground faster than the infection is being fought, and appetite loss is the point at which a manageable case becomes a critical one.

"Use the antibiotics left over from the dog."

Dosing is by weight and by drug, and several antibiotics that are routine in other species are inappropriate here. A partial course also selects for resistant bacteria, which is a genuine problem in the organisms that cause these infections.

The routine that catches it early

Hedgehogs conceal illness and only come out at night, so passive observation is not enough. Three habits do most of the work.

Weigh weekly, on the same scale, on the same day.

Weight is the single most sensitive early indicator in this species, and it is objective. A downward trend over two or three weeks is meaningful even when the animal looks fine.

Log the wheel.

Whether you use a mileage counter or just note how much bedding has been thrown around, night activity is a proxy for how the animal feels. A quiet wheel is an early warning.

Look at the nose in daylight, before the hedgehog wakes up properly.

Overnight discharge dries and crusts. By the time the hedgehog has been awake and grooming for an hour, the evidence has gone.

Appetite is the line between concerning and urgent. A hedgehog that walks away from food it normally finishes needs to be seen.

What the vet will want

Bring the husbandry data with the hedgehog. In this species it usually identifies the cause faster than the physical examination, because a hedgehog that balls up cannot be examined properly without sedation anyway.

Expect the vet to want radiographs of the chest, which usually means sedation, and possibly a nasal swab for culture. Sedation in a hedgehog with breathing difficulty carries risk, which is another reason to go early rather than late.

What never to do

Do not cool the room to make breathing easier. That is a mammalian intuition from human fever care and it is exactly wrong here: cooling a hedgehog suppresses its immune response and can trigger an attempted hibernation.

Do not bath a hedgehog with a respiratory infection. Wet fur and spines lose heat fast, and a sick hedgehog often cannot recover its temperature afterwards.

Do not pick off nasal crusts dry. Soften them with a damp cotton pad if the hedgehog tolerates it, or leave them for the vet.

Do not use an unregulated heat lamp or a heat mat without a thermostat while waiting for an appointment. Burns and overheating in a hedgehog that cannot move away are a common secondary injury.

Do not stop the antibiotic course early because the hedgehog seems better. Relapse after a shortened course is the usual reason a second infection is harder to treat than the first.

When to get help

Watch a resting hedgehog for a full minute. Breathing should be silent, even and shallow, with no movement of the flanks that you can see from across the room.

Contact a veterinarian with exotic mammal experience the same day for any breathing effort, open-mouth breathing, refusal to eat, or a hedgehog that is cold and will not uncurl.

Contact them within the week for repeated sneezing with a wet or crusted nose, any sound on breathing heard while the animal is undisturbed, or a weight trend that is going down.

While you arrange the appointment, keep the hedgehog warm at the upper end of its species range, remove dusty bedding and any scented product from the room, offer the food it likes most, and keep handling to the minimum needed to check on it.