Coccidioidomycosis in 26 horses in California, USA: case series and review of the literature. (November 2022)

• Record Type: Journal Article
• Authors: Macías-Rioseco, Melissa; Sheley, Matthew; Ochoa, Jennine; Carvallo-Chaigneau, Francisco R.; Uzal, Francisco A.
• Is Part Of: Journal of veterinary diagnostic investigation. Volume 34:Number 6(2022)
• Page Start: 995
• Page End: 999
• Publication Date: 2022-11
• Subjects: coccidioidomycosis -- horses -- pneumonia -- review; Veterinary medicine -- Diagnosis -- Periodicals; 636.0896075
• DOI: 10.1177/10406387221114622
• Languages: English
• ISSNs: 1040-6387

Abstract

Coccidioidomycosis is a fungal disease caused by Coccidioides immitis or Coccidioides posadasii . We searched the records of the California Animal Health and Food Safety Laboratory from 1990 through 2020 for cases of coccidioidomycosis in horses. The selection criteria for these cases were: 1) live-born horses submitted for autopsy, and 2) a diagnosis of coccidioidomycosis was established, regardless of cause of death. During that time, 19, 054 horses were received, and 26 cases (0.14%) of coccidioidomycosis were diagnosed in horses, of which 19 (73%) cases had pneumonia and/or pleuritis with or without lesions in other organs, and 7 (27%) cases had lesions only in organs other than the lungs (nasal mucosa, spleen, thoracic lymph nodes, heart, pericardial sac, liver, kidney, mediastinum, and/or mesentery). Pneumonia was diagnosed as the cause of death in 1, 838 (9.64%) of the horses received; Coccidioides spp. was the cause of pneumonia in 19 (1.0%) of these animals. Horses have been reported to have low susceptibility to coccidioidomycosis, and the severity and chronicity of the disease can be variable. Lesions in our cases consisted of multifocal-to-coalescing pyogranulomas with intralesional fungal spherules. Coccidioidomycosis must be considered a differential diagnosis in cases of persistent cough, chronic weight loss, fever, and cases with a travel history to, or living in, a region considered endemic for coccidioidomycosis. Coccidioides spp. infection should also be considered when pyogranulomatous inflammation is found within lung, spleen, nasal mucosa, and lymph nodes of horses.