Long-term follow-up of laryngeal Rhinosporidium seeberi diagnosed by PCR and treated with laser ablation and voriconazole nebulization in a retired thoroughbred polo horse.
Abstract: A 21-year-old retired polo Argentinian thoroughbred horse from a teaching herd was presented for a routine bronchoalveolar lavage demonstration, during which an incidental finding of a granulomatous mass on the dorsal aspect of the epiglottis was made. Rhinosporidium seeberi was suspected from a histological section obtained from an initial biopsy, and the mass was removed via laser surgery for cytology and PCR. Sequencing of the PCR amplicons confirmed the diagnosis of R. seeberi. A treatment protocol of nebulized voriconazole for 10 d postoperatively was used. Long-term follow-up required 2 more laser surgeries plus oral fluconazole to resolve the remaining fungal spores. However, 2.5 y later, there was no evidence of remaining fungal spores. Key clinical message: Horses from endemic regions can potentially be exposed to R. seeberi. Based on its travel history, this horse may have contracted the infection in South America, California, or Alberta. Treatments administered, including diode laser resection, voriconazole antifungal nebulization, and oral fluconazole administration, were successful but required repeated interventions. Suivi à long terme du Rhinosporidium seeberi laryngé diagnostiqué par PCR et traité par ablation au laser et nébulisation au voriconazole chez un cheval de polo thoroughbred pur-sang à la retraiteUn cheval thoroughbred argentin de polo retraité de 21 ans, issu d’un troupeau d’enseignement, a été présenté pour une démonstration de lavage broncho-alvéolaire de routine, au cours de laquelle une découverte fortuite d’une masse granulomateuse sur la face dorsale de l’épiglotte a été faite. Rhinosporidium seeberi a été suspecté à partir d’une coupe histologique obtenue à partir d’une biopsie initiale, et la masse a été retirée par chirurgie au laser pour cytologie et PCR. Le séquençage des amplicons PCR a confirmé le diagnostic de R. seeberi. Un protocole de traitement au voriconazole nébulisé pendant 10 jours après l’opération a été utilisé. Le suivi à long terme a nécessité 2 autres interventions chirurgicales au laser et du fluconazole oral pour éliminer les spores fongiques restantes. Cependant, 2,5 ans plus tard, il n’y avait aucune trace de spores fongiques restantes.Message clinique clé:Les chevaux des régions endémiques peuvent potentiellement être exposés à R. seeberi. D’après ses antécédents de voyage, ce cheval pourrait avoir contracté l’infection en Amérique du Sud, en Californie ou en Alberta. Les traitements administrés, notamment la résection au laser à diode, la nébulisation antifongique au voriconazole et l’administration orale de fluconazole, ont été efficaces mais ont nécessité des interventions répétées.(Traduit par Dr Serge Messier).
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The study is about a 21-year-old retired polo horse from Argentina that had a fungal infection identified as Rhinosporidium seeberi in its larynx, treated using laser surgery and the antifungal drug voriconazole. The treatment was successful, however, it required repeated procedures to fully clear the fungal spores.
Identification of Laryngeal Rhinosporidium Seeberi in a Horse
This research was conducted on a 21-year-old retired polo Argentinian thoroughbred horse that was part of a teaching herd.
The horse was initially presented for a routine bronchoalveolar lavage demonstration, a medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs to obtain fluid for diagnostic testing.
During this procedure, a granulomatous mass was unexpectedly discovered on the dorsal aspect of the horse’s epiglottis. The presence of Rhinosporidium seeberi, a type of fungus, was suspected from a histological section obtained from an initial biopsy.
The mass was removed using laser surgery, and the removed tissue was analysed using cytology and Polymerase Chain Reaction (PCR) processes. This confirmed the presence of Rhinosporidium seeberi.
Treatment of Rhinosporidium Seeberi
An antifungal treatment protocol was followed postoperatively. This involved the use of nebulized voriconazole, an antifungal medication, for 10 days.
The long-term follow-up of the horse’s medical condition required two more laser surgeries and oral administration of another antifungal drug, fluconazole, to completely eliminate the remaining fungal spores.
2.5 years after initial detection and treatment, there were no traces of remaining fungal spores.
Key Clinical Message
Horses from regions endemic with Rhinosporidium seeberi can potentially be exposed to this fungus.
Based on the travel history of the treated horse in this study, it is suggested that it might have contracted the infection in either South America, California, or Alberta.
The treatments employed, including diode laser resection, voriconazole antifungal nebulization, and oral fluconazole administration, effectively treated the Rhinosporidium seeberi infection but required repeated interventions.
Cite This Article
APA
Toner S, Leguillette R, Israel J, Legge C, Samani ARE, Kavanagh M, Goodmanson M.
(2024).
Long-term follow-up of laryngeal Rhinosporidium seeberi diagnosed by PCR and treated with laser ablation and voriconazole nebulization in a retired thoroughbred polo horse.
Can Vet J, 65(7), 667-674.
Faculty of Veterinary Medicine, University of Calgary, 11877 85th Street NW, Calgary, Alberta T3R 1J3.
Leguillette, Renaud
Faculty of Veterinary Medicine, University of Calgary, 11877 85th Street NW, Calgary, Alberta T3R 1J3.
Israel, Júlia
Faculty of Veterinary Medicine, University of Calgary, 11877 85th Street NW, Calgary, Alberta T3R 1J3.
Legge, Carolyn
Faculty of Veterinary Medicine, University of Calgary, 11877 85th Street NW, Calgary, Alberta T3R 1J3.
Samani, An Razieh Eshraghi
Faculty of Veterinary Medicine, University of Calgary, 11877 85th Street NW, Calgary, Alberta T3R 1J3.
Kavanagh, Molly
Faculty of Veterinary Medicine, University of Calgary, 11877 85th Street NW, Calgary, Alberta T3R 1J3.
Goodmanson, Mallory
Faculty of Veterinary Medicine, University of Calgary, 11877 85th Street NW, Calgary, Alberta T3R 1J3.
MeSH Terms
Animals
Horses
Horse Diseases / drug therapy
Horse Diseases / surgery
Horse Diseases / diagnosis
Voriconazole / therapeutic use
Voriconazole / administration & dosage
Antifungal Agents / therapeutic use
Antifungal Agents / administration & dosage
Male
Rhinosporidiosis / veterinary
Rhinosporidiosis / drug therapy
Rhinosporidiosis / surgery
Rhinosporidiosis / diagnosis
Nebulizers and Vaporizers / veterinary
Laser Therapy / veterinary
Polymerase Chain Reaction / veterinary
Laryngeal Diseases / veterinary
Laryngeal Diseases / surgery
Laryngeal Diseases / drug therapy
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