Fungal infections in horses encompass a variety of conditions caused by different fungal species that can affect the skin, respiratory system, and other body systems. These infections can range from superficial skin infections, such as ringworm, to more serious systemic infections like aspergillosis. The presence of fungi in the equine environment and their interactions with the horse's immune system can influence the development and severity of these infections. Diagnosis often involves identifying the specific fungal organism through laboratory testing, while treatment may include antifungal medications and supportive care. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenesis, diagnosis, and treatment of fungal infections in horses.
Bagy MM, Abdel-Mallek AY.Hair samples from different animals collected from different sites in Riyadh, Saudi Arabia were examined for the presence of saprophytic and keratinolytic fungi. Fifty-one specimens were examined of which 19 were from rabbits, 13 from sheeps, 12 from camels and 7 from horses. Forty-eight species and one variety which belong to 24 genera were collected during this investigation. The most common genera were Aspergillus and Chrysosporium. In low frequency, members of the genera Thermoascus, Scopulariopsis, Alternaria, Penicillium, Rhizopus, Botryotrichum, Fusarium, Ulocladium and keratinophilic f...
Grandguillot L, Fairbrother JM, Vrins A.A protected catheter brush introduced by fiberoptic bronchoscopy was used to sample the tracheai and bronchial mucosa in 28 horses with small airway disease. Tracheal and bronchial brushings were examined for the presence of fungi, aerobic and anaerobic bacteria, and a cytoiogical evaluation was also done on fluid collected by the bronchoalveolar lavage (BAL) technique. Microorganisms (bacteria and fungi) were isolated more often in tracheal brushings (53.6%) than in bronchial brushings (10.7%). Anaerobic bacteria were not isolated. Results of this study indicate that fiberoptic bronchoscopy u...
Hintz HF.Interest in mycotoxins and mycotoxicosis in humans and animals has greatly increased in recent years. Horses have long been considered very susceptible to molds. The signs, treatment, and prevention of several conditions, such as leukoencephalomalacia, aflatoxicosis, ergotism, fescue toxicity, slobbering disease, ryegrass staggers, and moldy sweet clover disease, are discussed.
Friedman DS, Schoster JV, Pickett JP, Dubielzig RR, Czuprynski C, Knoll JS, Wolfgram LJ.The fungal organism Pseudallescheria boydii was isolated from the cornea of a Quarter Horse with ulcerative keratitis. Despite aggressive hourly medication through a subpalpebral lavage system, with drugs including miconazole and natamycin, the cornea developed a stromal abscess. Orbital exenteration was performed after 3 weeks. The fungal isolate was later determined to be resistant to all 8 antifungal drugs tested. Microscopic examination of the cornea revealed fungal hyphae throughout the corneal stroma and penetrating the Descemet membrane. Pseudallescheria boydii has not been implicated p...
Vesonder R, Haliburton J, Golinski P.Feed samples of corn, pelleted feed, and oats associated with equine leucoencephalomalacia (ELEM) were obtained from North Carolina, Illinois, Indiana, and Oklahoma. These samples contained a high colony density of Fusarium moniliforme Sheldon which ranged from 64 to 87% of the total fungi. Fifty-nine F. moniliforme strains were isolated. Isolates of F. moniliforme in feed samples from Illinois, Indiana, and Oklahoma were cultured on corn. The fermented corn, mixed with regular feed and fed to one-day-old ducklings, effected a high mortality coefficient (average 55%). Methanol extracts of corn...
Shadomy HJ, Dixon DM.An unusual fungus, probably traumatically introduced into the eye of a horse while grazing, was studied on various mycological media. Upon examination of colonies the organism produced bulbils and clearly exhibited the characteristics of a new species of Papulaspora, P. equi Shadomy & Dixon.
Humber RA, Brown CC, Kornegay RW.A 15-year-old Arabian mare from southern Louisiana with a 2-month history of periodic epistaxis and severe weight loss had a large, fibrosing, granulomatous mass containing numerous nodules ("kunkers") projecting dorsally into the nasopharynx, and was euthanized at the owner's request. In addition to these kunkers, the mass contained a single trematode tentatively identified as Fasciola hepatica. Several kunkers were removed, washed thoroughly in sterile water and embedded in nutrient agars; the fungus that grew out of them was identified as Conidiobolus lamprauges Drechsler (Entomophthorales:...
Marasas WF, Kellerman TS, Gelderblom WC, Coetzer JA, Thiel PG, van der Lugt JJ.Each of two horses was dosed by stomach tube with culture material on maize of Fusarium moniliforme MRC 826. One horse developed severe hepatosis and mild oedema of the brain after 6 doses of 2.5 g of culture material/kg body mass/day in 7 days. The second horse, in a similar experiment but at a dosage rate of 1.25 g/kg/day, developed mild hepatosis and moderate oedema of the brain. In both animals the brain oedema was particularly noticeable in the medulla oblongata. The mycotoxin fumonisin B1 was extracted and purified from the culture material of F. moniliforme MRC, 826 which contained appr...
Gelderblom WC, Jaskiewicz K, Marasas WF, Thiel PG, Horak RM, Vleggaar R, Kriek NP.Cultures on corn of Fusarium moniliforme MRC 826 are known to cause leukoencephalomalacia in horses and to be toxic and hepatocarcinogenic in rats. Culture material of this F. moniliforme isolate has also been shown to exhibit cancer-promoting activity in a short-term cancer initiation-promotion bioassay with diethylnitrosamine-initiated rats and the induction of gamma-glutamyl-transpeptidase-positive (GGT+) foci as an endpoint after 4 weeks of promotion. This bioassay was used as a monitoring system to isolate cancer-promoting compounds from cultures of F. moniliforme MRC 826. Culture materia...
Ihrke PJ, Wong A, Stannard AA, Vivrette SL.The fungal flora of the hair and underlying skin from 2 sites was examined qualitatively in 20 horses free of skin or ocular disease. Fungi were isolated from both the hair and the underlying skin of all 20 horses. Twenty-two genera regarded commonly as saprophytes were identified and an additional 2 fungi resembled the perfect state of the cutaneous pathogenic genera Microsporum and Trichophyton. Cladosporium spp, Penicillium spp, and Rhizopus spp were the most frequently isolated saprophytes. In general, similar fungi were isolated from the hair and underlying skin, and differences were not ...
Cabañes FJ, Abarca L, Bragulat MR, Bruguera T.A phaeohyphomycotic infection caused by Alternaria alternata is reported in a 5-month-old Spanish mare. The diagnosis was made by direct microscopic examination and by repeated isolation of the fungus in culture. This is the first documented case to be reported in Spain.
Nansen P, Grønvold J, Henriksen SA, Wolstrup J.Interactions between the predacious hyphomycete Arthrobotrys oligospora and third-stage larvae of nine animal-parasitic nematodes were tested in vitro. The trap-inducing capabilities of the ruminant trichostrongylus Cooperia oncophora, C. curticei, Haemonchus contortus and Ostertagia ostertagi and of equine cyathostomes were almost comparable to those of free-living soil nematodes, and significantly higher than those of the porcine Oesophagostomum dentatum and Oe. quadrispinulatum and of the murine Nematospiroides dubius. The trap-forming potential of Dictyocaulus viviparus was poor. All anima...
McEntee M.A cutaneous mass (1.5 cm in diameter) was removed from the head of a horse and was diagnosed histologically as eumycotic mycetoma. Immunofluorescence, performed on formalin-fixed, paraffin-embedded tissue, identified Pseudallescheria boydii as the etiologic agent. Findings from earlier reports of eumycotic mycetoma were compared with those of this horse.
Clarke AF, Madelin TM, Allpress RG.The relationship between air hygiene within two types of identically managed horse housing and the incidence of covert respiratory disease (as revealed by endoscopic examination) of their inhabitants was assessed. The horses were all under the supervision of the same trainer. In one yard the design ensured the boxes were well ventilated in still air conditions. In the other yard the boxes were insulated and there was little provision for natural ventilation in still air conditions. There was heavy fungal and actinomycete contamination of wood shavings in the heavily insulated, poorly ventilate...
Abid HN, Walter PA, Litchfield H.A 6-year-old Quarter Horse gelding was examined because it had a sharply circumscribed, firm, brown-black, roughly spherical dermal nodule at the right tuber ischii. After it was excised, the lesion did not recur. Microscopically, the dermis of the excised specimen had multiple pyogranulomas, many of which contained thick-walled, dark brown fungal elements, some with internal septation compatible with chromomycotic fungi. Chromomycosis is a rare skin disease in the horse. It may be included in the differential diagnoses of nodular and/or pigmented skin lesions that include melanoma, pyogranulo...
Clarke AF, Madelin T.This paper describes and compares three techniques of categorisation of hay, straw and other feeds and beddings collected from stables. A hand-held sampler was used to categorise samples according to the presence of plant material, fungal spores and dust mites. An Andersen sampler was used to categorise samples according to the thermotolerances of fungi and actinomycetes. An aerodynamic particle sizer was used to categorise samples according to respirable particle release rates. The highest burden of respirable particles was associated with the presence of thermophilic and thermotolerant actin...
Webster AJ, Clarke AF, Madelin TM, Wathes CM.The concentration of fungal spores, the main constituents of respirable dust in stables, is determined by rates of release from fodder and bedding and rate of clearance, principally by ventilation. This paper outlines the principles that govern the application of natural ventilation to the control of air hygiene in barns and individual boxes for horses. When release rates are low, ventilation rates over four air changes per hour are satisfactory. Ventilation was satisfactory in individual boxes but usually unsatisfactory in barns and specific recommendations are made for improvement. Prelimina...
Caron JP, Fretz PB, Bailey JV, Barber SM, Hurtig MB.Epistaxis, caused by guttural pouch mycosis, was treated by balloon-tipped catheter and ligature occlusion of the involved arteries in 13 horses. In 7 horses, more than one artery was catheterized. Serious postoperative hemorrhage was prevented in all horses. Long-term endoscopic follow-up examination was possible in 8 horses, and all had complete regression of the fungal lesion as early as 5 weeks after surgery. Six of the 8 horses did not receive medical treatment. Problems related to the use of the balloon-tipped catheter technique were rare. There were incisional infections in 3 horses, ca...
Shipton WA.The equine phycomycotic agent known commonly as Hyphomyces destruens or occasionally as Pythium gracile, is described as a new species Pythium destruens. Separation is on the basis of morphological features, temperature growth profiles, esterase/lipase activity, and carbohydrate utilization ability. P. diclinum (synonymous with P. gracile sensu Middleton) showed minor differences in vesicle, oospore and oogonium size from P. destruens. P. destruens grew at 40 degrees C on corn meal agar and hydrolysed esters of lauric and oleic acids. These abilities were not displayed by P. diclinum, but this...
Grabner A.Mycosis of the guttural pouches is a sporadic disease characterized by diphtheroid-necrotizing inflammation, and is caused by different fungal species, mainly by Aspergillus spp., Penicillium spp. and Candida spp. Highest incidence is during summer in stable horses. Proper diagnosis often requires--besides detection by mycological techniques--histological examination of tissue obtained by bioptic endoscopy. Prognosis is hopeless in late stages of the infection because of the erosion of the carotid artery or accompanied by the fatal complications of a not reparable cranial nerve damage also in ...
Haack D.For the inoculation of the dermatophyte-test-medium Fungassay, 200 skin scrapings from horses, 13 from cattle and 13 from artificially infected guinea pigs were used. As control methods, the alkali method, the fluorescent microscope technique and the usual mycological culture were available. For the analysis of skin scrapings, the Fungassay culture mediums are clearly inferior to the usual mycological culture. Fewer dermatophytes were isolated and false positive as well as false negative results occurred. The cultivation of Trichophyton verrucosum failed on the dermatophyte-test-medium.
Adeyefa CA.The effects of the various growth factors with regard to the nutritional physiology of zoophilic dermatophytes isolated from horses are reported. The optimum temperature, pH and growth period for the fungal isolates were found to be 30 degrees-35 degrees C, 5-6 and 7-12 days respectively while the carbon and nitrogen sources utilised by the organisms were sucrose, fructose, maltose, L-arginine and calcium nitrate. The use of these factors in preparation of efficacious fungicides used in the treatment of ringworm infections in man and animals is discussed.
Gabal MA, Awad YL, Morcos MB, Barakat AM, Malik G.Mycotoxicoses involving horses, rabbits and cattle have been studied. Fusarium tricinctum and T-2 toxin were isolated from all incriminated feedstuffs. Other isolated trichothecenes from the feed included HT-2, verrucarins and roridin. The toxins were separated, identified and quantitated using thin-layer chromatography, gas-liquid chromatography and mass spectrometry. T-2 toxin was detected in amounts varying from 0.5-204 ppm. The contaminated feedstuffs in connection with the affected horses and rabbits, included cereal grains (corn, cornstalks, bran and barley), whereas fescue hay was assoc...
Adeyefa CA.The clinicopathological features and treatment of cases of dermatomycotic infections in horses are reported. Organisms isolated from these cases include Trichophyton mentagrophyte, T. equinum and Micosporum equinum. The Veterinary, medical and economic importance of the disease is discussed.
Krogh HV, Lundegaard HC.A case of guttural pouch mycosis in an 11-year-old horse is described. The fungus isolated was identified as Emericella nidulans. Housing under bad hygienic conditions without ventilation for three years might have been a predisposing factor.
Hoquet F, Higgins R, Lessard P, Vrins A, Marcoux M.A total of 43 horses were used for the study of the pharyngeal bacterial flora. The median value of the number of bacteria in the group of 19 normal horses was 3.8 x 10(4) cfu/g of secretions. This value was 6.4 x 10(4)cfu/g in horses with grade I pharyngitis, 1.3 x 10(5) cfu/g in horses with grade II pharyngitis and 3.5 x 10(6) cfu/g in horses affected with grades III and IV pharyngitis. Corynebacterium spp, coagulase-negative staphylococci, Nocardia spp, Moraxella spp and Enterobacter spp were the most frequently encountered bacteria in the normal animals as well as in horses affected with p...
Selim SA, Soliman R, Osman K, Padhye AA, Ajello L.Isolation of Histoplasma farciminosum from five horses, showing typical signs of histoplasmosis farciminosi (epizootic lymphangitis) was successfully attempted. The mycelial form of H. farciminosum was isolated on Sabouraud dextrose agar enriched with 2.5% glycerol, brain heart infusion (BHI) agar enriched with 10% horse blood and PPLO dextrose glycerol agar. The last medium proved to be the most effective, both for primary isolation and subculturing of the fungus. It was found that on primary isolation, the lag phase of the mycelial form of the fungus was relatively long, involving 4-8 weeks ...
Le Bars J, Le Bars P.Successful investigation and prevention of mycotoxic problems requires close collaboration between scientists from several disciplines ranging from agronomists and technologists required during production of food and feeds, to toxicologists and pathologists examining the effects of mycotoxins on animals and man. Zootoxic metabolites following fungal infection result from four general mechanisms: (i) secondary fungal metabolism (mycotoxins, eg, aflatoxins); (ii) bioconversion of vegetal compounds (eg, dicoumarol); (iii) plant reactions (phytoalexins, eg, coumestrol); and (iv) plant-fungus assoc...
Trápaga MR, Poester VR, Mousquer MA, de Souza RP, Rafael LA, Bonel J, Melo AM, Reis AG, de Faria RO, Stevens DA, Nogueira CEW, Xavier MO.Aspergillosis is an uncommon disease in horses, but it can be fatal. We report two cases of systemic aspergillosis in foals that occurred in a short period in the same region of southern Brazil. In addition, a literature review of similar cases was also performed. Risk factors were attributed to an immunodepression by primary enterocolitis and corticosteroid treatment, the damage in the epithelium, and multiple antibacterial treatments, which allowed local fungal proliferation, tissue invasion and spread of infection, leading to death. Since the antemortem diagnosis of aspergillosis in foals i...
Hosny OH, Abd-Elkareem M, Ali MM, Ahmed AF.Ulcerative keratitis is a common disease in horses which may cause blindness. To prevent secondary bacterial and fungal infections and promote quick re-growth of the epithelial layer, different treatment approaches have been employed. This study aimed to examine the effects of advanced platelet-rich fibrin (A-PRF) gel on the healing process of experimentally induced corneal ulcers in donkeys. Nine healthy adult donkeys were used for the study. The donkeys were divided into two groups: the control group, where no medication was applied to the corneal ulcer, and the A-PRF gel group, where A-PRF ...
Medical mycologyDecember 6, 2023
myad124 doi: 10.1093/mmy/myad124
Wernery U, Joseph M, Joseph S, Al Mheiri F.Epizootic equine lymphangitis (EEL) is a chronic fungal disease that affects equids. The causative agent is a dimorphic fungus called Histoplasma capsulatum var farciminosum. H. capsulatum var farciminosum field strain 7 (D 2878/2023) isolated from the eye socket of an EEL Ethiopian horse was sub-cultured on 4 different solid media and incubated at 26°C and 37°C for 6 weeks. Details of growth morphology were recorded and shown in images during 6 weeks of incubation. H. capsulatum var farciminosum grew best at 26°C on all 4 agars, but only on sheep blood agar at 37°C as small, white dry col...
Anbalagan E, Malathi S.The human body's largest organ is the skin which covers the entire body. The facial skin is one area of the body that needs careful handling. It can cause several facial skin diseases like acne, eczema, moles, melanoma, rosacea, and many other fungal infections. Diagnosing these diseases has been difficult due to challenges like the high cost of medical equipment and the lack of medical competence. However, various existing systems are utilized to detect the type of facial skin disease, but those approaches are time-consuming and inaccurate to detect the disease at early stages. To address var...
Woo PCY, Mheiri FA, Cavalleri J, Joseph S, Tang JYM, Joseph M, Tsang CC, Lau SKP, Wernery U.Epizootic lymphangitis (EL) is a highly prevalent and contagious infectious disease affecting horses in many parts of Ethiopia caused by Histoplasma capsulatum sensu lato ('var. farciminosum'). In this study, 12 suspected isolates of H. capsulatum sensu lato or yeasts unidentified by conventional biochemical tests isolated from Ethiopian horses with EL were characterised by ITS sequencing. Six of the 12 isolates were identified to be members of H. capsulatum sensu lato and the other six were Pichia kudriavzevii (synonym: Candida krusei) (n = 3), Trichosporon asahii (n = 1), Geotrichum silv...
Dély S, Gerber V, Peters LM, Sage SE.The presence of fungi in tracheal wash (TW) of horses was recently linked to mild-moderate equine asthma, indicating a possible causal role; however, increased numbers of fungi may also stem from asthma-related alteration of tracheal mucus clearance or from environmental exposure. Our objective was to elucidate the association between the presence of fungi in TW and asthma status while controlling for relevant confounders. We conducted a retrospective case-control study involving 73 horses, including 34 controls and 39 asthmatic cases. Each asthmatic horse was matched with a control from the s...
Böswald LF, Gottschalk C, Kaltner F, Merk J, Schwaiger K, Kienzle E.While previous reports come mostly from the southern Americas, several outbreaks of hypersalivation in horses were observed in Middle Europe from 2016 to 2018. Objective: To describe feed-induced hypersalivation in European horses. Methods: Analysis of feedstuffs. Methods: Veterinarians and horse or stable owners were encouraged to submit feedstuffs from case outbreaks of hypersalivation in which, infectious diseases or other systemic causes of the syndrome were ruled out and intoxication was suspected. Feedstuff analysis was performed, including gross examination, microscopic analysis of fine...
Kurras S, Knottenbelt D, Schmelz U, Schaal T, Tischendorf T, Fuchs R, Schorling T, Koene MHW.Dermatophytosis is a common fungal skin infection in horses, particularly affecting young and immunocompromised animals. Traditional treatments often involve antifungal medications with potential side effects. Here, we present a case report that evaluated the efficacy of cold atmospheric plasma-aerosol (CAP-A) as a standalone treatment for equine dermatophytosis. Unassigned: A 2-year-old Westphalian warmblood stallion presented with confirmed dermatophyte lesions restricted to the left side of the mouth which were treated with CAP-A. Treatment was administered 2 times daily for 12 consecutive ...
Chagoya-Fuentes JL, Gaona-López J, Hernández-Carbajal GR, Torres-Guerrero H, Lammoglia-Villagómez MA, Huerta-Peña J, Pérez-Brígido CD....A clinical case of an adult horse with invasive, ulcerative, proliferative, pyogranulomatous disease of the skin (tumor) in the shoulder region is presented. The mass had a granulomatous and crater-shaped appearance, with serosanguinous discharge and the presence of fistulas with caseous material. The tumor was removed by surgery and sent to the laboratory for diagnosis. Histopathology was performed using Grocott-Gomori methenamine silver stain. The presence of necrotic material, fibrosis, infiltrated cells, and brown-colored hyphae, characteristic of members of the genus Pythium, were observe...
Abebaw B.An adult male black horse was presented to the UOG veterinary clinic with swelling, discharge, and skin wounds on the chest wall and the right front leg; then, it goes to the lateral and medial hind leg. Inspection and palpation were carried out, and we revealed that the skin was swelled, thickened and hard on clinical examination. There was also nodule rupture, and discharge on the limb and chest skin. Different therapy was applied starting from washing the wound with water-diluted potassium permanganate and then 0.9% NaCl together with paraffin topically placed on the wound. 10% povidone-iod...
Krogh HV, Lundegaard HC.A case of guttural pouch mycosis in an 11-year-old horse is described. The fungus isolated was identified as Emericella nidulans. Housing under bad hygienic conditions without ventilation for three years might have been a predisposing factor.
Wernery U, Nothelfer HB, Böhnel H, Collins WR.An acute outbreak of a C. perfringens Type C enterotoxemia in a polo club killed 8 polo ponies in less than 24 hours. Hay with a massive fungal contamination (Aspergillus and Fusarium sp.) is suspected to have triggered the enterotoxemia. Our cases show numerous similarities with the previously reported cases of EIC. However, acute toxic tubulonephrosis in the necropsied horses and longstanding elevation of AST and gamma GT-levels in survivors is unique in our cases.
Guillot J, Collobert C, Gueho E, Mialot M, Lagarde E.A case is reported in a 9-year-old Anglo-Arab horse with guttural pouch mycosis caused by Emericella nidulans. Acute death occurred by exsanguination following erosion of the external carotid artery. Histopathological examination of the mycotic plaque demonstrated septate hyphae, conidial heads, hülle cells and mature cleistothecia containing characteristic ascospores. Specific identification was confirmed by culture. In accordance with previous reports, Emericella nidulans should be considered as the major agent of guttural pouch mycosis in Equidae.
Elad D, Blum S, Kol A, Ederi N, David D.A case of equine eumycotic mycetoma caused by Madurella mycetomatis is described. This is the first report of M. mycetomatis as the etiologic agent of human or animal infections in Israel. The definitive identification of the isolate was established by molecular methods. In addition the mold was cultured on various media through which we found that its growth rate was significantly augmented on incubation on trypticase soy agar, more so if horse serum was added to this medium. Sixteen previously published cases defined by the authors as mycetoma in horses are briefly reviewed. Among these, onl...