Feline Coccidioidomycosis

1 Feline Coccidioidomycosis

Clinical symptoms of feline coccidioidomycosis

Infected cats show elevated temperature, persistent cough, labored breathing, loss of appetite, weight loss, lethargy and diarrhea. When bone is affected, lameness and muscle atrophy occur.

Pathological changes of feline coccidioidomycosis

Swollen bronchial or mediastinal lymph nodes and pericardial effusion; granulomas in the pleura, pericardium, heart, lungs, liver, spleen and stomach.

Differential diagnosis

(1) Feline coccidioidomycosis vs. feline toxoplasmosis

Both show elevated temperature (above 40°C), anorexia, cough, emaciation and diarrhea.

Difference: toxoplasmosis is caused by Toxoplasma gondii. Chronically the temperature reaches 39.7-41.1°C, with iritis and conjunctivitis, and pregnant queens abort. At necropsy there is congestion and subcutaneous hemorrhage on the hind limbs, abdomen and ear pinnae, pulmonary edema, cut surfaces ooze clear yellow fluid, scattered small nodules throughout the lungs, and Toxoplasma can be seen on impression smears stained with Wright’s stain.

(2) Feline coccidioidomycosis vs. feline viral rhinotracheitis

Both show poor appetite, elevated temperature and cough.

Difference: viral rhinotracheitis is caused by a virus. Affected cats have serous or mucoid nasal discharge, conjunctival congestion and edema, dendritic corneal congestion and tearing. At necropsy the nasal, laryngeal and bronchial mucosa is necrotic; multinucleated giant cells and intranuclear inclusion bodies are seen in upper respiratory epithelium.

(3) Feline coccidioidomycosis vs. feline tuberculosis

Both show mild fever, reduced appetite, cough and labored breathing.

Difference: tuberculosis is caused by Mycobacterium tuberculosis. There are rales in the lungs, starting with a dry cough that turns productive, later producing purulent mucus that is grayish-white or slightly green, with blood-tinged nasal discharge. At necropsy the tuberculous lesions look sarcomatous; nodules are grayish-white or yellow-white; liver lesions are centrally depressed, and when the capsule ruptures pus drains, forming cavities; the lungs show nodules, caseation (later cavitating with pus) or calcification. Smears stained by the acid-fast method show red, medium-sized, straight and slightly curved tubercle bacilli.

(4) Feline coccidioidomycosis vs. feline histoplasmosis

Both show fever, cough, diarrhea, anorexia and emaciation.

Difference: histoplasmosis is caused by Histoplasma. Affected cats show vomiting and dermatitis. X-ray shows pulmonary nodules and enlarged bronchial and visceral lymph nodes. An intradermal test aids diagnosis.

(5) Feline coccidioidomycosis vs. feline paragonimiasis

Both show cough, diarrhea and fever.

Difference: paragonimiasis causes severe morning cough, starting dry then productive, with thick sputum that is initially white then rust-colored or brown. Fecal examination reveals eggs (round, golden-yellow).

Notes

The disease mainly presents as elevated temperature, loss of appetite, cough, labored breathing, emaciation and diarrhea. Skeletal muscle infection causes lameness and muscle atrophy. The coccidioidin sensitivity test is positive. X-ray and fluorescent antibody tests can confirm the diagnosis.

Prevention and treatment

(1) Prevention

Keep the environment and cat bedding clean. For sick cats, disinfect their excreta (urine, feces, vomit, sputum) with disinfectant before deep burial.

(2) Treatment

Treatment takes a long time, so it should not be interrupted.

1. Ketoconazole: 5-10 mg/kg body weight, orally, twice daily, for at least 3-6 months. If bone is affected, lifelong treatment may be needed.

2. Stopping treatment can cause relapse. Lifelong maintenance dose: 5 mg/kg body weight.