Is Mould Dangerous for Pets? What Every Pet Owner Should Know

When people think about mould health risks, they think about themselves and their families. But pets are often more vulnerable to mould exposure than humans — and less able to tell you something is wrong. If you have mould in your home, your furry companions deserve the same consideration.

How mould affects pets

Mould produces spores and, in some cases, mycotoxins — toxic compounds that can cause illness when inhaled, ingested, or contacted through the skin. Pets are susceptible to all three exposure routes, and their size, behaviour, and biology can make them more vulnerable than their human housemates.

Inhalation

Pets breathe the same air you do. If airborne mould spore levels are elevated in your home, your pets are inhaling them constantly. Dogs and cats with shorter snouts (brachycephalic breeds like Pugs, French Bulldogs, and Persian cats) may be especially affected, as their airways are already compromised.

Ingestion

This is where pets face a unique risk. Dogs explore the world with their mouths. Cats groom themselves obsessively. If mould is growing on surfaces your pets lick, chew, or walk on — then groom off their paws — they are ingesting mould spores and potentially mycotoxins directly.

Pets that chew on mouldy materials (timber, leather, fabric, or even mouldy food scraps from the bin) face a particularly high risk of mycotoxin poisoning.

Skin contact

Mould spores can cause contact dermatitis in pets, particularly on their belly, paws, and any areas with thin fur. Pets that lie on mouldy carpet, bedding, or flooring are in constant contact with the source.

Symptoms of mould exposure in dogs

Dogs show a range of symptoms depending on the species of mould, the level of exposure, and the individual dog's health. Watch for:

• Respiratory symptoms — coughing, wheezing, laboured breathing, nasal discharge, sneezing
• Skin irritation — excessive scratching, redness, rashes, hair loss, hot spots
• Digestive issues — vomiting, diarrhoea, loss of appetite, drooling
• Lethargy — unusual tiredness, reluctance to exercise or play
• Neurological symptoms (in severe mycotoxin exposure) — tremors, seizures, loss of coordination, disorientation
• Bleeding — in rare cases of severe mycotoxin poisoning (particularly from Stachybotrys), dogs may develop bleeding disorders

If your dog is showing any combination of these symptoms and you know or suspect mould in your home, mention it to your vet. Mould exposure is often overlooked as a cause.

Symptoms of mould exposure in cats

Cats can be harder to read, as they tend to hide illness. Signs include:

• Respiratory distress — open-mouth breathing, panting (abnormal for cats), coughing, wheezing
• Excessive grooming — particularly of the paws and belly
• Skin irritation — scabs, hair loss, or redness, especially on the face and ears
• Nasal and eye discharge — clear or coloured discharge, squinting
• Behavioural changes — hiding, loss of appetite, aggression, withdrawal
• Vomiting or diarrhoea — particularly if the cat has ingested mould through grooming

Cats with feline asthma are especially vulnerable to airborne mould spores.

Which pets are most at risk?

While all pets can be affected, some are at higher risk:

• Brachycephalic breeds (flat-faced dogs and cats) — already compromised airways
• Young animals — developing immune and respiratory systems
• Senior pets — weakened immune systems
• Pets with pre-existing respiratory conditions — asthma, bronchitis, or chronic cough
• Immunocompromised animals — pets on steroids, chemotherapy, or with conditions like FIV in cats
• Small animals — birds, guinea pigs, hamsters, and rabbits have highly sensitive respiratory systems. Birds in particular can become critically ill from airborne mould spores

A note on birds

Birds deserve special mention. Their respiratory systems are extraordinarily efficient — and extraordinarily sensitive. Aspergillosis, a fungal infection caused by Aspergillus mould, is one of the most common causes of illness and death in captive birds. If you keep birds and have a mould problem in your home, address it urgently.

How pets encounter mould differently

Pets interact with mould sources in ways humans typically do not:

• They are closer to the ground — mould on skirting boards, carpet, and flooring is at their face height
• They explore with their noses — dogs especially will sniff directly at mouldy patches
• They groom mould off their fur and paws — ingesting spores that settle on their coats
• They sleep on the floor — prolonged contact with contaminated surfaces
• They cannot tell you — by the time symptoms are obvious, exposure may have been occurring for weeks or months

What your vet may recommend

If your vet suspects mould-related illness, they may:

• Run blood tests to check for immune response or organ damage
• Take X-rays or ultrasound if respiratory symptoms are present
• Prescribe antifungal medication for confirmed fungal infections
• Recommend removal from the environment until the mould is addressed
• Treat symptoms — antihistamines, bronchodilators, or anti-nausea medication as needed

The most important treatment, however, is eliminating the mould source. No medication will resolve the problem if your pet continues to be exposed. Consider professional air purification to reduce airborne spore levels in your home.

Protecting pets during mould remediation

Mould remediation temporarily increases airborne spore levels before reducing them. This makes the remediation period itself a high-risk time for pets:

• Remove pets from the property during active remediation. Board them with a friend, family member, or kennel
• Do not return pets until the remediation is complete and the space has been thoroughly ventilated
• Wash all pet bedding, bowls, and toys after remediation — or replace them if they were in the contaminated area
• Monitor your pet for symptoms in the weeks following remediation, as some effects can be delayed

Why the treatment method matters

Traditional mould remediation often involves harsh chemical treatments — bleach, ammonia-based products, or synthetic fungicides. These chemicals can leave residues on surfaces that pets then walk on, lie on, and lick. For a pet that grooms its paws, chemical residues are a genuine concern.

This is one of the reasons we use SAN-AIR technology at Pureairo. Our surface mould removal process uses SAN-AIR — a 100% natural, plant-based treatment system. It contains no synthetic chemicals, no bleach, and no toxic residues. Once treatment is complete and the area is ventilated, it is safe for pets to return. This matters when you have animals that interact with surfaces in ways humans simply do not.

Prevention for pet owners

• Address mould promptly — do not wait for it to spread. Small patches are cheap to fix; large infestations are not
• Keep pet areas dry — wash and dry water bowls regularly, keep bedding clean and dry, ensure litter trays are in well-ventilated spaces
• Monitor humidity — keep indoor humidity below 60%
• Ventilate — particularly in rooms where pets spend most of their time
• Check hidden spots — behind furniture, under sinks, inside wardrobes, and in laundry areas where moisture accumulates

Concerned about your pets?

If you have mould in your home and pets in your family, getting the problem resolved quickly and safely is doubly important. At Pureairo, our natural SAN-AIR treatment eliminates mould without introducing chemicals that could harm your animals.

If you are worried about mould affecting your pets, get in touch for a free assessment. We will evaluate the situation and recommend the safest path forward — for every member of your household.