What are Coccidioidomycosis?
Outdoor cats have a higher predisposition for developing fungal infections. Coccidioidomycosis can only be contracted by coming into contact with infected soil or inhaling infectious dust particles. The infection may spread to other areas of the body. Additionally, cats are more likely to develop lesions in the lungs as a result of the infection compared to other species.
Coccidioidomycosis, commonly known as Valley Fever, is a rare type of fungal infection caused by the fungus Coccidioides immitis that primarily affects the respiratory system. The infection is most prevalent in areas with dry, hot climates, including the southwestern United States, Mexico, and South America. While humans and many other kinds of animals can develop coccidioidomycosis, the condition is not contagious. Though it is not typically contagious, do not allow your cat to bite you if you suspect it is infected with coccidioidomycosis. There has been one reported case of cat-to-human transmission via cat bite.
Symptoms of Coccidioidomycosis in Cats
Symptoms of coccidioidomycosis in cats may be varied and nonspecific. While fungal infection is not typically considered a serious condition, coccidioidomycosis is considered more serious in cats than in other animals due to the associated symptoms. The infection often causes lesions in the lungs, which can lead to more serious respiratory problems. You should seek immediate veterinary attention if you notice any of the following symptoms:
- Pus-filled or draining lesions on the skin
- Difficulty breathing
- Weight loss
- Loss of appetite
- Signs of eye and/or neurological abnormalities
Causes of Coccidioidomycosis in Cats
The only way a cat can develop coccidioidomycosis is through contact with the fungus C. immitis. This fungus may be found in soil or dust particles, particularly in hot, dry areas since the fungus thrives in extreme temperatures. Coccidioidomycosis is endemic to the southwestern U.S. In certain “hot spots” where the fungus is particularly abundant, as much as 70 percent of the human population has contracted coccidioidomycosis.
While the disease is not considered zoonotic – or able to be transmitted from animals to people – one case has been reported of a veterinary assistant contracting coccidioidomycosis after being bitten by an infected cat. However, the infection was resolved following treatment.
Diagnosis of Coccidioidomycosis in Cats
Your vet will first perform a thorough physical examination and make a tentative diagnosis based on presentation of symptoms. Be sure to inform your vet of the extent and duration of your cat’s symptoms as well as any currently prescribed medications. The vet may ask for your recent travel history, particularly if your cat has been to any arid locations.
Your vet will reach a definitive diagnosis by examining tissue samples, usually taken from the respiratory system, and confirming the presence of C. immitis. Blood serum tests are one of the most effective methods for diagnosing coccidioidomycosis. Your vet may also take x-rays of the chest to check for lesions in the lungs and other organs.
Treatment of Coccidioidomycosis in Cats
Treatment will depend on whether or not there are chronic symptoms associated with the disease. Cases of coccidioidomycosis presenting acute symptoms are treated with oral antifungal medications. Fluconazole is the most commonly prescribed antifungal medication, although there are other options available. These medications are typically prescribed for six to twelve months and administered daily. Be sure to inform your vet of any medications your cat is already taking, as some anti-fungal medications can react with other medications or have adverse side effects.
Treating coccidioidomycosis with chronic symptoms is slightly more difficult and tends to involve long-term therapy. In cases of coccidioidomycosis with chronic respiratory symptoms and signs of disseminated disease, antifungal treatment may last as long as a year or more.
There are currently no vaccines available to treat or prevent coccidioidomycosis. Other treatments may also be recommended depending on the symptoms present. Your vet will advise you on a treatment plan based on your cat’s specific needs.
Recovery of Coccidioidomycosis in Cats
Recovery and prognosis are generally good following treatment. Always follow your vet’s post-treatment instructions carefully. Always administer medications exactly as directed for the full duration of the recommended treatment period. Failure to do so could result in aggressive recurrence. Never apply any topical ointments or creams made for human use to your cat’s lesions as this could cause damage to the skin and make the condition worse.
Employing preventative measures is important in safeguarding your cat from coming into contact with the fungus. You may want to limit your cat’s outdoor activity, especially if you live in a high-risk area. Cats have an increased chance of coming into contact with the fungus after rain spells and during dust storms.
Your vet may schedule follow-up appointments as needed to monitor the condition, particularly in cases in which chronic respiratory symptoms are present. If the condition does not appear to be improving with treatment or if your cat experiences any side effects, contact your vet immediately.