Why Is My Cat’s Ear Full of Gunk? The Causes of Yeast Infections in Cats

What is a Yeast Infection in Cats?

A yeast infection in cats, also known as candidiasis or thrush, is caused by an overgrowth of yeast or fungus on the skin or mucous membranes of a cat’s body. The most common culprit is the Candida albicans fungus. Yeast is present naturally in small amounts on healthy cat skin, but an overgrowth can lead to infection.

Common symptoms of a yeast infection in cats include:[1]

  • Ear infections
  • Skin issues like irritation, redness, and sores
  • Oral thrush
  • Vaginitis in female cats
  • Greasy skin or hair loss

Yeast infections in cats often occur in moist areas of the body like folds of skin, the ears, mouth, and genitals. Treatment typically includes antifungal medications prescribed by a vet.

Causes and Risk Factors

There are several potential causes and risk factors that can lead to yeast infections in cats:

Warm, moist areas of a cat’s body are prone to yeast overgrowth. Areas like the ears, mouth, skin folds, and genital area provide ideal conditions for yeast to thrive [1].

Cats with weakened immune systems are more susceptible to yeast infections. Conditions like feline leukemia virus and feline immunodeficiency virus can suppress the immune system and allow opportunistic yeast to grow [2].

The use of antibiotics can kill off good bacteria that keep yeast in check. Without this beneficial bacteria, yeast populations can expand rapidly [1].

Underlying diseases like diabetes can increase blood sugar levels, promoting yeast overgrowth. Diabetic cats tend to get recurring skin and ear infections [3].


Some common symptoms of yeast infections in cats include:

  • Discharge from the ears or eyes – This is often thick, waxy, and may have a bad odor. Ear infections caused by yeast can lead to head shaking and scratching.
  • Hair loss – Patches of hair loss may occur if yeast settles on the skin.
  • Itchy skin – Yeast can cause severe itching, redness, and irritation on the skin.
  • Weight loss – If a yeast infection affects the digestive tract, cats may lose their appetite and lose weight.
  • Lethargy – The infection can make cats feel unwell, leading to low energy and fatigue.

Other signs include greasy skin, dandruff, and lesions on the skin or eyes. Drooling can occur with oral thrush infections. Diarrhea may be present if the intestinal tract is affected.


If a yeast infection is suspected, the vet will perform a thorough physical exam of your cat. They will look for common signs of a yeast infection like skin lesions, hair loss, greasy skin, and itching. The vet may take a sample of your cat’s skin for examination under a microscope, which is called a skin scraping or skin cytology. This can help identify an overgrowth of yeast.

The vet may also take a sample of discharge from lesions for a fungal culture test. This allows the yeast to grow in a laboratory so it can be identified. A biopsy of the skin may sometimes be done as well.

Your vet may recommend blood tests to check for underlying conditions that could make your cat prone to fungal infections. This includes tests for diabetes, Cushing’s disease, and feline immunodeficiency virus (FIV).

With a combination of a physical exam, skin tests, and blood work, your vet can determine if a yeast infection is the cause of your cat’s symptoms.


Treatment for yeast infections in cats focuses on clearing up the infection with anti-fungal medicines, improving hygiene, and using topical creams or ointments.

Common anti-fungal medicines used include fluconazole, itraconazole, and ketoconazole. These are usually given orally and help fight the yeast infection throughout the body. The medication course is typically 2-4 weeks. Sources: https://wagwalking.com/cat/condition/fungal-yeast-infection, https://www.petmd.com/cat/conditions/infectious-parasitic/c_ct_candidiasis

Keeping the cat’s environment clean is also important to prevent reinfection or spreading. This includes disinfecting food bowls, bedding, litter boxes, and other items the cat comes in contact with regularly. Grooming can help remove yeast from the fur and skin as well.

Topical anti-fungal creams, ointments, or medicated shampoos may be prescribed to treat localized infections on the skin or ears. These can include miconazole, ketoconazole, or other anti-fungal ingredients. The topicals treat the infection site directly while the oral medication treats the whole body.

Home Remedies

There are some natural home remedies that may help treat a yeast infection in cats. Two commonly used remedies are apple cider vinegar and coconut oil.

Apple cider vinegar has antifungal properties that can help inhibit the growth of yeast. To use it, mix a 50/50 solution of apple cider vinegar and water. Use a cotton ball to apply this solution to the affected areas of your cat’s skin. Be sure to sufficiently dilute the vinegar, as it can irritate skin in high concentrations. Only apply to external areas and avoid contact with eyes, nose, and mouth.[1]

Coconut oil is another home remedy with antifungal properties. Look for pure, organic, extra virgin coconut oil. You can apply a small amount directly to the infected area. Coconut oil helps moisturize skin and has anti-inflammatory effects as well. [2]

Plain, unsweetened yogurt contains probiotics that can help restore balance to your cat’s microbiome and fight yeast overgrowth. Apply a small amount to the affected area and let sit for 5-10 minutes before gently wiping off. Make sure your cat does not lick off the yogurt. [2]


There are several steps cat owners can take to help prevent yeast infections in their pets:

Proper grooming and hygiene are important. Regularly bathe your cat with a gentle, antifungal shampoo. Gently clean the ears with a cotton ball dampened with diluted apple cider vinegar to maintain the proper pH balance. Keep the fur trimmed neatly around the rear to prevent feces from clinging to the skin. Change the litter frequently to keep the area clean.

Manage any underlying conditions, like diabetes, that can allow yeast to overgrow. Keeping blood sugar levels controlled through diet, medication, and regular vet checkups helps prevent infections. Discuss probiotic supplements with your vet to support healthy bacteria levels.

Limit antibiotic use which can kill off beneficial bacteria and allow yeast to thrive. Only use antibiotics when truly necessary and be sure to finish the full course as prescribed by your vet. You may consider probiotic therapy during and after a course of antibiotics.

With diligent care and attention, many yeast infections can be avoided in cats. But if an infection does occur, prompt veterinary treatment is key to relief and recovery.

When to See a Vet

It’s important to take your cat to the vet if the symptoms of a yeast infection persist or worsen. Some signs that indicate a vet visit is needed include:

  • The infection spreads to other parts of the body or becomes more inflamed/irritated
  • Symptoms like skin irritation, ear inflammation, or respiratory issues don’t improve with home treatment
  • Loss of appetite, lethargy, or other signs of illness develop
  • You notice signs of dehydration like reduced skin elasticity, dry gums, or sunken eyes
  • Your cat seems to be in a lot of discomfort from itching/inflammation

A vet can do tests to diagnose the yeast infection and identify the specific fungus involved. This allows them to prescribe the most effective antifungal medication to clear up the infection. They can also provide additional treatments for symptoms and give suggestions on managing any underlying conditions contributing to the infection’s development.

Left untreated, yeast infections in cats can worsen and lead to complications like skin ulcers, tissue damage from scratching, and secondary infections. It’s important not to delay veterinary care if home treatment isn’t improving the infection within a few days. With the right medical care, most cats fully recover from yeast infections.

Outlook and Complications

Yeast infections in cats are usually easily treatable if caught early and addressed properly. With prescription antifungal medication from a veterinarian, most cats make a full recovery within 2-4 weeks. Mild infections limited to just the skin, ears or paws can sometimes be cleared up with over-the-counter antifungal creams or medicated shampoos.

However, the infection can recur if the underlying cause is not addressed. Things like allergies, antibiotic use, diabetes or a compromised immune system may make a cat prone to repeat infections. Identifying and controlling these risk factors is important to prevent recurrence.

There is also a risk of the infection spreading to other pets in the home. Cats with skin lesions or ear infections may leave infectious yeast behind on shared items like bedding. Keeping the infected cat isolated during treatment and washing all bedding can help reduce transmission.

Key Takeaways

Yeast infections in cats are caused by an overgrowth of yeast on the skin, ears, or other areas. Risk factors include allergies, antibiotic use, poor diet, diabetes, and a weakened immune system. Symptoms include itchy skin, scaly patches, head shaking, and ear discharge. Diagnosis is made through skin scrapings, tape preps, blood tests, and fungal cultures. Treatment depends on the location and severity but may include antifungal medication, medicated shampoos, and dietary changes. Preventing yeast infections focuses on managing risk factors and keeping the cat’s immune system strong. Seeing a vet is recommended to properly diagnose the infection and rule out other causes. Left untreated, yeast infections can worsen and lead to secondary infections. With prompt treatment and prevention, cats can recover fully.

To prevent yeast infections in cats, feed them a balanced diet low in carbs and sugars. Control flea and environmental allergies. Avoid overusing antibiotics and only use them when prescribed by a vet. Check for signs of diabetes or other immune deficiencies. Keep your cat’s skin and ears clean and dry. See your vet regularly and at the first signs of an infection. With vigilance and proactive care, you can help keep your cat healthy and yeast free.

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