Why does my cat have bad breath?

Why does my cat have bad breath?

There are several possible reasons:

• Diet: Your cat's breath might smell like fish for a short time after eating, but this should be temporary. A good quality, complete diet is recommended for optimal health and wellbeing, including oral health.  
• Oral infections and abscesses: Bacteria from these can produce foul smells. Regular vet check-ups can catch these problems early, especially in breeds prone to dental issues.
• Objects getting stuck in teeth: Food, hair, or string caught between your cat's teeth can cause bad breath as they decompose. Watch for signs like pawing at the mouth, drooling, sore or bleeding gums, or avoiding hard food.
• Systemic diseases: Conditions like kidney disease, feline diabetes, and liver disease can cause different breath odours. For example, kidney disease can cause a urine-like smell, while diabetes may give the breath an unusually sweet, fruity scent. See your vet immediately if your cat has bad breath and other symptoms like weight loss or drinking more water.
• Stomatitis: If your cat has severe mouth inflammation, known as stomatitis, it's likely to cause bad breath. Cats with stomatitis may also show signs like pawing at the mouth or refusing food.
• Tumours: Oral tumours can cause tissue decay and very bad breath.

Long-term effects of untreated bad breath in cats

If left untreated, the underlying conditions causing bad breath can get worse. Plaque can turn into tartar, leading to gum disease. This condition damages the tissues supporting the teeth, potentially leading to tooth loss and infections, both of which can cause ongoing dental problems and chronic pain. In severe cases, the bacteria that come with periodontal disease can enter the bloodstream, possibly affecting other organs such as the heart and kidneys.

Chronic bad breath in cats caused by illnesses like kidney disease or diabetes can indicate that these conditions are not well managed and may lead to further complications. Regular veterinary check-ups, particularly as your cat ages, can help catch these issues early before they lead to more severe health problems. Cats will often continue to eat despite dental conditions, so never take a good appetite as a sign that all must be okay. 

Read more: How many teeth do cats have?

How to treat and prevent bad breath in cats

Treating cat bad breath involves addressing the underlying cause. Here's what you can do:

• Regular dental care: Like us, cats can benefit from a trip to the dentist. Having your cat's teeth professionally cleaned when recommended by your vet is a great way to prevent bad breath and other dental issues. During these cleanings, your vet will thoroughly check all teeth, remove plaque and tartar and extract any teeth that can't be saved. Maintaining this routine for older cats or breeds prone to dental problems is especially important.
• Brushing your cat's teeth: Regular brushing at home is a hugely beneficial way to improve your cat’s oral hygiene and will reduce plaque build-up. Use a toothbrush and toothpaste designed specifically for cats - never use human toothpaste. It may take some time for your cat to get used to this, so start slowly and gently. If your cat resists brushing, you could try dental wipes or gels.
• Dietary adjustments: Increasing the amount of dry food in your cat's diet, or switching to a prescription dental diet, can help reduce plaque build-up. Additionally, dental treats designed to clean teeth can be useful supplements - these can be high in calories so use sparingly. Look for products approved by the Veterinary Oral Health Council (VOHC). Be mindful of your cat's overall diet to ensure it supports good oral health.
• Treating underlying health conditions: If your cat has bad breath due to a condition like diabetes or kidney disease, treating the underlying issue is crucial. In these cases, your vet may prescribe medication or suggest dietary changes.
• Dental chews and water additives: Consider using dental chews and water additives with the Veterinary Oral Health Council (VOHC) seal of approval. These can help reduce plaque and freshen your cat's breath. Starting these practices early in your cat's life can help prevent dental issues later. Introduce water additives cautiously - some cats can be put off from drinking by changes to their water source.

Read more: Post-dental care guide for your pet

What the studies say

In 2021, a Swedish study on cat dental problems and owner perceptions found that only 37% of cat owners who claimed to be aware of dental issues in their pets recognised bad breath as a clinical sign of these problems​. Although no UK study has been carried out investigating the same topic, this suggests a potential widespread lack of awareness, and many cat owners may be overlooking bad breath as a sign of serious dental conditions.
More evidence that bad breath in cats should be taken seriously can be found in a 2022 study in the Journal of Veterinary Dentistry. The study demonstrated that cat halitosis is statistically linked with dental pain. The study found that, due to the existing dental conditions causing their bad breath, cats with halitosis experienced sensitivity and discomfort when handled by vets.

Need more advice on your cat's dental care?

If your cat's breath smells despite regular home care, or if you notice symptoms like drooling, difficulty eating, or pawing at the mouth, use our find a vet page to find your nearest vet, or speak to a vet online using our video vet service.

Looking for more expert advice on maintaining your cat's dental health? Visit our cat dental care hub for all the essentials.

Prevention is always better than cure, so start taking steps today to protect your pet’s teeth. Members of Pet Health Club get 10% off dental procedures.