How To Avoid Mould and Mildew in Your Rabbit Hutch

A mouldy hutch is an unsafe hutch. Mould and mildew in your rabbit hutch can make your bunnies sick or even kill them. It can also damage the hutch. Learn how to protect your rabbit and your rabbit’s enclosure safely and effectively.

Mould in your house can be a health hazard. Mildew and mould in your rabbit hutch can be equally hazardous for your rabbits. On top of that, they can both weaken the wood of your rabbit’s home, eventually making that home unsafe to occupy.

Mould and mildew can become a problem -- a big problem -- for your rabbit even before you know it’s there. Prevention is key. But what if you already have a problem? Don’t worry. There are ways of dealing with mildew and mould in a rabbit hutch that is both effective and safe.

What are Mould and Mildew?

Mould and mildew are fungi. They thrive in moist or humid environments, though some types can live in drier climates as well.

The main differences between mould and mildew are their appearance and the type of damage they cause. In general, mould can cause more and greater damage to both health and property. But mildew can make your rabbit sick, too.

The different types of mould

Mould comes in many different colours, including yellow, green, blue, brown, white, grey, and black. It usually has a fuzzy appearance.

Many types of mould are harmless. Some, like the mould used to produce certain cheeses, are even beneficial. The harmful ones, however, cause several different kinds of problems.

These include:

• Allergic reactions
• Toxicity
• Exacerbating existing health conditions

This last point is an important one. Because rabbits are prone to respiratory problems, inhaling mould spores can be particularly dangerous for them.

The different types of mildew

There are two main types of mildew: powdery and downy. Downy mildew often starts out yellow then turns brown. Powdery mildew looks like a powder. It begins white but later becomes black, brown, or yellow.

Where Mould and Mildew Grow

Where might your rabbit come across mould or mildew? Turns out, there are quite a few places.

The hutch itself

Mould and mildew can grow on wooden rabbit hutches if those hutches encounter excess moisture. That moisture might come from rain, from splashback from gutters or drainage pipes, from water dripping off of leaves after a rainfall, from a dripping water bottle, or even from a rabbit’s own urine. It might grow for a long time before you notice it.

Plastic and metal enclosures may also grow mould if moisture is allowed to gather.

The litter tray

Urine and faeces provide the moisture and nutrition that mould loves. It’s important to spot-clean your rabbit’s litter box daily to discourage fungal growth. Training your rabbit to use a litter tray will make cleaning easier and keep urine in one place.

Read how to litter train your rabbit here.

Toys and accessories

Toys and accessories can also grow mould if not regularly cleaned.

Food and hay

Mould can grow on uneaten fresh food. It can also grow on hay. Inspect your hay before giving it to your rabbit. Hay should have that “fresh hay” smell and not have black spots or other signs of mould.

Remove uneaten fresh food at the end of each day, and change out hay daily.

Water bottles

Water bottles are a prime spot for mould growth, first because many people don’t clean them as often as they should, and also because they’re leak-prone. Empty, wash and refill your rabbit’s water bottle daily. Also, check for leaks. Leaks are annoying, but they’re very common. Here’s one solution:

How Mould and Mildew Can Harm Your Rabbit

The symptoms of mould poisoning are different, depending upon whether your rabbit has inhaled the fungi or ingested it.

Symptoms of inhaled mould poisoning

If your bunny is exhibiting respiratory symptoms, mould or mildew may be to blame. Symptoms of inhaled mould or mildew include:

• Laboured breathing
• Rapid breathing
• Coughing
• Sneezing
• Wheezing
• Nasal discharge which may include blood

Symptoms of ingested mould poisoning

If your rabbit has eaten mould or mildew, they may experience different symptoms, such as:

• Decreased appetite
• Changes in stool including blood in the faeces
• Diarrhoea
• Abdominal pain

Other symptoms

Other symptoms of mould exposure may include:

• Discharge from the eyes
• Sores around the face and mouth
• Low body temperature

Longer-term damage from mould poisoning

Exposure to mildew and mould in a rabbit hutch can cause other problems. You might not notice these problems immediately, but they can be just as serious. They include:

• Liver damage
• Kidney damage
• Gangrene
• Constricted blood flow
• Reproductive damage to females
• Vitamin K deficiency

How your vet may treat mould or mildew exposure

If you think your rabbit may be suffering from mould or mildew exposure, it’s important to take them to your vet right away. 

Your vet will generally offer your rabbit supportive care. This may include treatment of respiratory, skin, and digestive symptoms. It may also include IV fluids for dehydration from diarrhoea. If your bunny is suffering from an allergic reaction to mould or mildew, your vet may also administer appropriate anti-allergy medication. 

What can you do About Mildew and Mould in a Rabbit Hutch?

The best treatment is prevention. But what if you’ve already found mildew and mould in your rabbit hutch? Don’t worry. We’ll help you sort that out, too.

How to treat mildew and mould in a rabbit hutch

First, remove your rabbit and their dishes and toys from the hutch. Next, dispose of all hay and bedding. Then deal with the mould.

Mould remediation expert Nick Nembhard recommends the following steps.

1. Gather your materials. You’ll need:
   • A scrub brush or stainless steel scrubbing pad. Sandpaper can also help with stubborn spots.
   • A mild non-toxic detergent like dishwashing liquid
   • A rabbit-safe disinfectant
   • A dry cloth
   • A  vacuum with a HEPA filter
2. Suit up. Put on an N95 respirator, safety goggles, and rubber gloves.
3. Inspect the hutch, not only to find the mould but to find the source of the excess moisture.
4. Apply the detergent to the mould. Be careful not to oversaturate the wood.
5. Scrub the mouldy patch until it’s clean.
6. Wipe the excess moisture away with a dry cloth.
7. Apply the rabbit-safe disinfectant to the area.
8. Dry the wood again.
9. Vacuum the wood with the HEPA vacuum.
10. Wait 24 hours for the wood to dry completely.

While the wood is drying, take the time to wash and disinfect your rabbit’s toys, dishes, and water bottles.

You can also use distilled white vinegar instead of detergent, but the process is a little different.

First, use the HEPA vacuum to remove spores from the surface of the wood. Then put the vinegar into a spray bottle and spray it onto the mould or mildew. Wait 40 to 60 minutes, then scrub and let dry as above.

How to Stop Mould and Mildew Before They Begin

Preventing mildew and mould in a rabbit hutch takes some planning and thought. But it’s not hard. Are you ready?

Hutch and hutch placement

First, you need the right hutch. Choose a raised hutch (one where the floor doesn’t sit on the ground) with adequate ventilation.

Next, weatherproof your hutch. Most hutches are pre-treated but after the first year, it’s advised to retreat your hutch. Choose a rabbit-safe wood treatment. This means:

• Water-based
• No heavy metals
• Does not contain creosote
• Low on volatile organic compounds (VOCs)

A rain cover can also help to protect your hutch from moisture.

Now, check your hutch placement. This can be a tricky balance. You want your pets to be safe, warm and dry, but also to have adequate ventilation. The hutch also needs to be clear of drainage pipes or other sources of excess moisture.

Here are a few places not to put your hutch:

• In a damp area of your garden
• Under trees or in a part of your garden that rarely sees the sun
• Next to or touching trees, hedges or bushes. Their leaves can drip water onto your hutch long after the rain stops.
• Near a gutter or drainpipe. Splash from these can seep into the wood of the hutch, encouraging mildew and mould.

You can site your Hutch in any of these places included above and plenty of owners do, but doing so will mean your hutch is at a higher risk and will need more attention.

Instead, choose a part of your garden that has a good mixture of fresh air and sunshine. If you live in a hot climate, make sure that the spot you choose doesn’t have too much sunshine, as rabbits are very sensitive to heat. Also, ensure that air can flow well through and beneath the hutch.

After a rainfall, your hutch and hutch cover will be wet. Remove the cover and hang it to dry. If the hutch itself is wet, remove your rabbit and any hay, food, and bedding, and allow the hutch to dry, too.

Anti-mould hutch maintenance

Do you have a hutch maintenance routine? You should. It takes a bit of extra work, but your rabbit’s health is worth it.

Do the following daily.

• Remove uneaten fresh food and hay
• Spot-clean the litter box
• Wash out food and water dishes
• Empty, clean, and refill the water bottle
• Look for moisture spots and deal with them
• Inspect the hutch for visible mould or mildew.

You may be tempted to let your litter tray duties slide. Don’t. Urine provides moisture that encourages fungal growth. On top of that, the faeces of plant-eating animals are highly nutritious and moist. Mould will grow on it quickly.

At the same time, you do want to leave some faeces in the litter box, as they are an important supplement to your rabbit’s diet. Rabbits usually consume cecotropes in the morning or at night. So leave a few pellets when you do your spot-clean, then clear them away if they’re still there the next day.

These tasks can be done weekly:

• Check for white marks on the walls or floor of your hutch. These come from urine. The moisture can encourage mould. Clean them with vinegar.
• Remove all toys and accessories from the hutch. Wash them with dish soap and warm water.
• Change out your rabbit’s bedding. Dispose of disposable bedding and wash fabric bedding.
• Wipe down plastic or metal enclosures with warm water and vinegar
• Disinfect plastic or metal enclosures with a rabbit-safe disinfectant or a solution of one part bleach to ten parts water.

Final Thoughts

Mildew and mould are common, especially in damp and humid climates. They can grow slowly and insidiously for a long time before you might notice them. And by that time, they might have already damaged both your hutch and your pet’s health.

The best way to keep mildew and mould out of your hutch is to prevent it from growing in the first place. Choose the right model hutch, place it somewhere with plenty of airflow and sunshine, and invest in weather protection. Inspect your hutch for mould and mildew regularly, and develop a daily and weekly cleaning routine.

And if you do notice mildew and mould in your rabbit hutch, treat it immediately and aggressively.

Do you have any tips for preventing or treating mildew and mould in a rabbit hutch? Let us know in the comments!

And for more information on how to keep your bunny happy check out our rabbit library here.