Introduction
Antifungal medications are used to treat fungal infections in cats. Common fungal infections in cats include ringworm, yeast infections, and systemic fungal infections like blastomycosis or histoplasmosis. It’s important to use an antifungal medication that is safe and effective for cats when treating a fungal infection. Using the wrong antifungal can lead to toxic side effects in cats. This guide covers the types of fungal infections in cats, symptoms to look out for, available antifungal medications, and how to choose and administer a safe antifungal treatment for your cat.
Types of Fungal Infections in Cats
Some of the most common fungal infections seen in cats include:
Ringworm
Ringworm is a highly contagious fungal skin infection caused by Microsporum canis. It causes circular bald patches and scaly skin on a cat’s head, ears, legs, and feet (Merck Veterinary Manual). Ringworm spreads easily between cats and other animals through direct contact and contaminated objects. It can also spread to humans.
Aspergillosis
Aspergillosis is a fungal infection caused by Aspergillus mold spores. It often starts in the respiratory system but can spread to other organs. Common symptoms include sneezing, nasal discharge, difficulty breathing, and ulcers in the nose and mouth (VMSG).
Blastomycosis
Blastomycosis is caused by the fungus Blastomyces dermatitidis and primarily affects the lungs, causing pneumonia, coughing, fever, and difficulty breathing. Skin lesions may also occur. It is uncommon but can be fatal if left untreated (Flat Rock Veterinary Clinic).
Cryptococcosis
Cryptococcosis is an infection caused by the fungus Cryptococcus neoformans. It often starts as a respiratory illness but can disseminate to other areas like the skin, eyes, and central nervous system. Common symptoms include sneezing, nasal discharge, skin lesions, and neurologic issues (Merck Veterinary Manual).
Histoplasmosis
Histoplasmosis is caused by the fungus Histoplasma capsulatum. The fungal spores are inhaled and infect the lungs, causing pneumonia, coughing, and difficulty breathing. Disseminated histoplasmosis spreads the infection to other areas of the body (VMSG).
Symptoms of Fungal Infections
Fungal infections in cats can cause a variety of symptoms depending on the type of fungus and which part of the body is affected. Some common symptoms of fungal infections in cats include:[1]
– Skin lesions/hair loss – Fungal infections of the skin, like ringworm, often lead to circular patches of hair loss and skin lesions. The lesions may be red, scaly, and itchy.
– Nasal discharge – Fungal infections in the nasal cavity or sinuses can cause chronic nasal discharge. The discharge may be clear, bloody, or contain mucus or pus.
– Coughing – Fungal infections in the lungs, like blastomycosis, can lead to pneumonia and coughing. The cough may be dry and hacking or productive with phlegm.
– Lethargy – Systemic fungal infections that spread through the body can cause lethargy, depression, and generally feeling unwell.
– Fever – Fungal infections often cause fever, especially if the infection is systemic.
– Weight loss – Chronic fungal infections can suppress appetite and lead to weight loss.
[1] https://www.guilfordjamestownvet.com/site/blog-greensboro-vet/2021/02/12/fungal-infections-cats
Diagnosing Fungal Infections
Diagnosing fungal infections in cats typically starts with a physical examination. The veterinarian will look for signs of infection like skin lesions, eye discharge, ear inflammation, and swelling along the nasal passages or other areas. They may take samples by swabbing affected areas or doing skin scrapings to collect fungi for identification.
Fungal cultures are an important diagnostic tool. Samples collected from the cat are incubated to allow any fungal organisms to grow. Once growth occurs, the fungi can be identified to determine the species and best treatment options.
Biopsies may also be taken if deeper tissue evaluation is needed. Samples of the infected tissue are examined under a microscope to visualize the presence of fungi and identify the type. Biopsies are considered the most accurate method for diagnosing fungal infections.
Imaging tests like X-rays, MRIs, or CT scans may be used to evaluate internal fungal infections affecting the lungs, sinus cavities, or other areas. These tests allow veterinarians to see the extent of the infection and determine if or where surgery may be required.[1]
Antifungal Medications
There are several types of antifungal medications that can be used to treat fungal infections in cats:
Azoles
Azoles such as fluconazole and itraconazole work by interfering with the fungal cell membrane production. They are commonly used for systemic and intestinal fungal infections in cats. Fluconazole is given orally, while itraconazole can be given orally or via injection (Antifungal Cat Meds: Sprays, Lotions and Oral – PetSmart).
Terbinafine
Terbinafine is an antifungal medication that works by inhibiting ergosterol synthesis, an essential part of fungal cell membranes. It is effective against dermatophytes and can be used to treat superficial fungal infections in cats when given orally (Cat Medications Antifungal – VetRxDirect).
Amphotericin B
Amphotericin B binds to ergosterol in the fungal cell membrane, causing pores to form that leak cell contents. It can be used to treat systemic fungal infections in cats but is typically reserved for more serious infections due to potential kidney toxicity (Cat Antibiotics and Antifungal Products – scaHealth).
Griseofulvin
Griseofulvin disrupts fungal cell division by interfering with microtubule function. It is one of the oldest antifungal drugs and is used to treat dermatophytosis or ringworm infections in cats when given orally (Griseofulvin Tablets – VetRxDirect).
Choosing a Safe Antifungal
When choosing an antifungal for cats, it’s important to consider potential side effects and choose a pet-specific formula. Some key tips:
Consider side effects. Antifungals can cause liver damage, so it’s essential to monitor liver enzymes and function. Mild gastrointestinal upset is also possible. Discuss risks vs. benefits with your veterinarian.
Choose pet-specific formula. Look for antifungals made just for cats, not human medications. Pet meds are tailored to feline physiology. Popular options include itraconazole and fluconazole.
Consult veterinarian. Don’t give any medication without guidance from a vet. They’ll prescribe the right antifungal, dosage and duration based on your cat’s case. Follow instructions exactly.
Monitor liver function. Your vet will likely recommend periodic bloodwork to check on liver enzymes while on antifungals. Alert them to any signs of liver trouble like jaundice, vomiting or appetite loss.
With careful selection and monitoring, antifungals can safely and effectively treat infections in cats. Work closely with your veterinarian to choose the right medication for your feline companion.
Administering Antifungal Medications Safely
It’s important to follow the dosage instructions provided by your veterinarian to safely administer antifungal medications to cats. Oral antifungals like itraconazole are typically prescribed at 5-10 mg/kg once daily for 2-4 weeks, with the medication given for 1 week followed by 1 week off, repeating for the duration of treatment (1). This pulsed dosing helps minimize side effects. Giving the medication with food can help prevent upset stomach. Administering the full treatment course as prescribed is critical, even if symptoms resolve, to prevent recurrence. Also, watch closely for side effects like vomiting, diarrhea, or liver issues and notify your vet if they occur.
With close adherence to your veterinarian’s dosage instructions and monitoring for side effects, antifungal medications can be safely administered to cats in most cases.
(1) https://www.merckvetmanual.com/pharmacology/systemic-pharmacotherapeutics-of-the-integumentary-system/antifungals-for-integumentary-disease-in-animals
Lifestyle Changes
There are some lifestyle changes you can make at home to help prevent the spread of fungal infections between cats, or contaminating the home environment. These include:
- Disinfecting the home environment with a pet-safe disinfectant to kill any fungal spores
- Washing all bedding, blankets, cat towers, scratching posts, etc. thoroughly to remove fungal contamination according to product instructions
- Keeping cats with fungal infections separated from other cats to avoid spread between cats. This may mean housing them in separate rooms.
Making these simple changes can help prevent fungal infections from persisting in the home and lower the chances of transmission between cats. Be sure to follow your veterinarian’s additional recommendations for lifestyle changes to best support your cat’s health.
Prognosis
The prognosis for fungal infections in cats depends on the type of infection and how well the cat responds to treatment[1]. While some mild surface fungal infections can be cleared up quickly with topical antifungal medications, systemic fungal infections like blastomycosis often require months of oral antifungal treatment. Even then, the infection can come back later if the cat’s immune system remains compromised.
Close follow-up care with a veterinarian is very important when treating a cat for a fungal infection to monitor their response to treatment. Blood tests may be recommended during treatment to check if fungal markers are decreasing[2]. For fungal infections that tend to recur like ringworm, the cat’s skin and coat should be monitored long-term for any signs of the infection coming back.
With aggressive treatment under a veterinarian’s supervision and preventative care at home, the prognosis for fungal infections in cats can often be good. However, severe systemic fungal infections or those that fail to respond to initial treatment can potentially be life-threatening if not properly managed.
Prevention
There are a few key things cat owners can do to help prevent fungal infections in their feline companions:
Practice good hygiene by keeping your cat’s food and water bowls clean, washing bedding frequently, and cleaning the litter box daily. Fungal spores can accumulate in areas your cat frequents, so keeping things clean reduces exposure.
Avoid areas with lots of molds and fungi like compost piles or rotting wood, and ventilate humid areas well. Reducing your cat’s contact with fungal spores in the environment helps prevent infection.
Feed your cat a nutritious diet and keep their immune system strong. Cats with compromised immune systems are more prone to fungal infections. Providing excellent nutrition and minimizing stress supports good immune function.
Regular grooming and bathing can remove fungal spores from your cat’s coat and skin before they can take hold. Brush frequently and use a gentle, antifungal shampoo on occasion.
Take your cat to the vet annually for a wellness checkup. Early diagnosis allows fungal infections to be treated promptly before they worsen.
By promoting cleanliness, reducing exposure, and supporting immune health, cat owners can help prevent problematic fungal infections in their pets.
