Equine Veterinary Education Oropharyngeal Botryomycosis in a Geriatric Mare Journal: Equine Veterinary Education Manuscript ID EVE-CR-2016-120.R2 Fo Wiley - Manuscript type: Case Report Date Submitted by the Author: n/a r Complete List of Authors: Merchán Muñoz, Alejandro; Unitat Equina, Fundació Hospital Clínic Veterinari (Facultat de Veterinària, Universitat Autònoma de Barcelona), Re Servei de Cirurgia Equina Jose-Cunilleras, Eduard; Universitat Autonoma de Barcelona Facultat de Veterinaria, Medicina i Cirurgia Animals Prades, Marta; Universitat Autonoma de Barcelona Facultat de Veterinaria, Medicina i Cirurgia Animals vi Ribera, Thaïs; Fundació Hospital Clínic Veterinari (Facultat de Veterinària, Universitat Autònoma de Barcelona), Servei de Cirurgia Equina, Departament de Medicina i Cirurgia Animals ew Viu, Judit; Universitat Autonoma de Barcelona Facultat de Veterinaria, Medicina i Cirurgia Animals Rodriguez Pozo, Maria; Universitat Autonoma de Barcelona Facultat de Veterinaria, Medicina i Cirurgia Animals Ramis, Antonio; Universitat Autonoma de Barcelona Facultat de On Veterinaria, Sanitat Animal i Anatomia Discipline: Infectious diseases, Internal medicine Body System/Disorder: Respiratory: upper airways < Respiratory ly Botryomycosis is an uncommon chronic bacterial infection that can have cutaneous and visceral involvement. This report describes an 18-year-old mixed-breed mare presented with dysphagia, dyspnea, and an upper respiratory noise that developed secondary to oropharyngeal Abstract: botryomycosis. Histological examination of the mass showed a granulomatous formation with Splendore-Hoeppli phenomenon surrounding gram-positive bacteria. This report describes clinical signs, approach and management of an oropharyngeal Staphylococcus aureus granuloma in a geriatric mare. Note: The following files were submitted by the author for peer review, but cannot be converted to PDF. You must view these files (e.g. movies) online. ESTEL_DE_SOLAMELLES_20130204101829_1042390.avi Page 1 of 25 Equine Veterinary Education Fo r Re vi ew On ly Equine Veterinary Education Page 2 of 25 1 Case Report. 2 Oropharyngeal Botryomycosis in a Geriatric Mare. 3 A. Merchan,1* E. Jose-Cunilleras,1 M. Prades,1 T. Ribera,1 J. Viu,1 M. L. Rodríguez-Pozo,1# A. J. 4 Ramis.2 1 5 Unitat Equina, Fundació Hospital Clínic Veterinari, Carrer de l'Hospital s/n, Campus UAB, 6 Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona. 7 08193 Bellaterra (Cerdanyola del Vallès), Spain. 2 8 Servei de Diagnòstic de Patologia Veterinària, Departament d’Anatomia i Sanitat Animal, Fo 9 Universitat Autònoma de Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain 10 r * 11 Present address: Hagyard Equine Medical Institute, Lexington, Kentucky, USA Re # 12 Present address: Hospital Veterinario San Vicente, Sant Vicent del Raspeig, Alicante, Spain 13 vi 14 Corresponding author: E. Jose-Cunilleras ew 15 email: eduard.jose.cunilleras@uab.cat 16 Tel. +34 935 811 968 On 17 FAX. +34 935 813 428 18 ly 19 20 Keywords: Botryomycosis, Staphylococcus aureus, granuloma, oropharynx, potassium iodide. 1 Page 3 of 25 Equine Veterinary Education 21 Summary 22 Botryomycosis is an uncommon chronic bacterial infection that can have cutaneous and visceral 23 involvement. This report describes an 18-year-old mixed-breed mare presented with dysphagia, 24 dyspnea, and an upper respiratory noise that developed secondary to oropharyngeal botryomycosis. 25 Histological examination of the mass showed a granulomatous formation with Splendore-Hoeppli 26 phenomenon surrounding gram-positive bacteria. This report describes clinical signs, approach and 27 management of an oropharyngeal Staphylococcus aureus granuloma in a geriatric mare. Fo r Re vi ew On ly 2 Equine Veterinary Education Page 4 of 25 28 Introduction 29 Cutaneous and visceral botryomycosis has been described in equids, ruminants, companion 30 animals, guinea pigs, elephant and humans for over a century. (Bollinger 1870, Bostrom et al 1969, 31 Sheikh-Omar and Abdullah 1985, Bonifaz and Carrasco 1996, Pandey et al 1997, Margaret et al 32 2001, Miller et al 2001, Sleeman, J et al 2003, Scott 2007). Botryomycosis is an uncommon 33 condition, characterized by formation of a slow growing chronic granuloma caused by non- 34 filamentous aerobic and anaerobic bacteria such as Staphylococcus aureus, Pseudomona spp. and 35 Bacteroides. S. aureus is the most common agent encountered. Fo 36 Diagnosis is based on histological identification of granulomatous inflammation and isolation of the 37 microorganism. In the case described herein, a subepiglotic oropharyngeal granuloma caused by S. r 38 aureus was diagnosed based on the characteristic histologic findings and positive culture. Re 39 Histologically, botryomycosis is characterized by the presence of radiating, star-like asteroid or 40 club-shaped eosinophilic material, Splendor-Hoeppli (SH) reaction around the infectious agent; vi 41 which represents a localized immunological host reaction to antigens (Hussein 2008). Fungal ew 42 granulomas, bacterial abscessation, foreign body, amyloidosis, and neoplasia should be included in 43 its differential diagnosis. (Miller and Campbell 1982, Shaw et al. 1987, Kiper et al. 1992, Jones On 44 1994) 45 This report describes the clinical manifestations of a granuloma caused by S. aureus in the ly 46 oropharynx of a geriatric mare outlining a diagnostic and surgical approach as well as management 47 of the case. To the authors’ knowledge this is the first case of botryomycosis in the oropharynx 48 described in equine. 3 Page 5 of 25 Equine Veterinary Education 49 Case history 50 An 18-year-old mixed breed mare weighing approximately 450 kg was presented to Fundació 51 Hospital Clínic Veterinari of the Universitat Autònoma de Barcelona, with a 3-year history of a 52 mass located in the submandibular area and a second mass in the pharyngeal region. Over the 53 month prior to admission, the mare was occasionally pyrexic and presented intermittent dysphagia. 54 The mare also had episodes of dyspnea, upper respiratory noise, and bilateral mucoid nasal 55 discharge, especially when exercised. 56 Fo 57 Clinical findings 58 On presentation, the mare was quiet, alert and responsive. Physical exam was within normal limits. r 59 Bilateral mucoid nasal discharge was evident. Two firm, round shaped and smooth masses were Re 60 palpable in the submandibular and pharyngeal areas to the right side of midline, 5 and 3 cm in 61 diameter respectively. The skin overlying the masses was normal and there was no evidence of pain vi 62 or pruritus. ew 63 Ultrasonography of the submandibular mass revealed soft tissue density with multiple hypoechoic 64 compartments. The pharyngeal mass was encapsulated with the presence of punctiform hyperechoic On 65 structures and mineral opacities as well as hypoechoic areas similar to the other mass. (Fig 1) No 66 communication between the two masses was identified. An ultrasound guided fine-needle aspirate ly 67 was obtained under local anesthesia with mepivacaine from both masses. Cytology revealed mixed 68 neutrophilic and mononuclear inflammatory cells with presence of gram-positive cocci and 69 bacterial culture was negative. 70 Skull radiography revealed a well circumscribed, round soft tissue radio-opacity in the oropharynx 71 over the base of the tongue that obscured the epiglottis and hyoid apparatus over which it was 72 superimposed. 73 Endoscopy of the upper respiratory tract (URT) revealed the soft palate protruding dorsally into the 74 nasopharynx as though being pushed upwards. The soft palate was displaced dorsal to the epiglottis 4 Equine Veterinary Education Page 6 of 25 75 throughout the endoscopic examination. Oral endoscopy identified a 3 cm diameter, ulcerated pink 76 mass at the base of the tongue slightly offset to the right of midline that occluded the end of the 77 oropharynx (Fig.2). This mass was attached to the base of the tongue and ventral aspect of the 78 epiglottis. This finding explained the dysphagia and dyspnea. 79 Treatment 80 Surgical resection under general anesthesia was performed in two different procedures. Pre- 81 operatively, total protein and fibrinogen were elevated at 9.8 g/dl and 800 mg/dl respectively. 82 Rebreathing exam and thoracic ultrasonography were normal. Complete blood count, serum Fo 83 biochemistry and electrocardiogram were within normal limits. 84 The patient received pre-operative sodium penicillin1 (22.000 IU/kg bwt i.v.), gentamicin2 (6.6 r 85 mg/kg bwt i.v.), phenylbutazone3 (4.4 mg/kg bwt i.v.) and morphine2 (0.1 mg/kg bwt i.m.). Re 86 The mare was sedated with romifidine4 (0.06 mg/kg bwt i.v.) and butorphanol3 (0.03 mg/kg bwt 87 i.v.), induced with ketamine5 (2 mg/kg bwt i.v.) and diazepam6 (0.05 mg/kg bwt i.v.), placed in vi 88 dorsal recumbency and maintained with isoflurane7 in 100% oxygen through a mid cervical ew 89 tracheotomy performed prior to induction. 90 Initial intraoral examination under general anesthesia revealed a fibrous mass, approximately 1.5 x On 91 5 x 3 cm, from the base of the tongue to the oropharynx and slightly offset to the right of midline, 92 involving the mucosa of the oropharynx. ly 93 The ventral aspect of the head and neck were clipped and prepared aseptically. Surgery was 94 performed through a submandibular approach and continued by pharyngotomy as well as intraoral 95 manipulation. The submandibular mass extended to the oropharynx involving contiguous structures 96 such as the hyoid apparatus. Because of the location of the mass, surgical excision was unsuccessful 97 in achieving clean margins. The submandibular area was sutured in four layers: mucosa, muscle, 98 subcutaneous tissue and skin; and the pharyngotomy was left to heal by second intention. The 99 oropharyngeal mass excised surgically was fixed in 10% formalin and processed routinely for 5 Page 7 of 25 Equine Veterinary Education 100 histopathological studies. Hematoxilin-eosin and Gram staining were performed on the different 101 sections. 102 Two days later, under intravenous anesthesia with xylazine, ketamine, and guafenesin, the second 103 surgery was performed in sternal recumbency. Through an intraoral approach, the remaining part of 104 the mass adhered to the right aryepiglottic fold was removed (Fig.3). Laparoscopic instruments 105 were used for the procedure guided by nasal endoscopy. Additionally, an adhesion between the 106 subepiglottic fold and epiglottis was excised. 107 Diagnosis Fo 108 The different sections of the samples evaluated showed a similar histopahologic image: the normal 109 architecture of the tissue was extensively obliterated by irregularly sized pyogranulomas constituted r 110 by collections of degenerate neutrophils with variable numbers of surrounding macrophages, Re 111 epithelioid cells and foreign body multinucleated cells. A dense fibrovascular granulation tissue 112 infiltrated mainly by lymphocytes and plasma cells was seen between pyogranulomas. Within the vi 113 pyogranuloma there were numerous cocoid Gram positive stained bacterial colonies imbedded in an ew 114 amorphous eosinophilic material deeply eosinophilic, Splendore-Hoeppli phenomenon (Fig. 4). The 115 histological diagnosis was focally extensive severe pyogranulama with intralesional Gram positive On 116 bacteria, compatible with botryomycosis. 117 Culture of the mass isolated coagulase positive Staphylococcus aureus and antimicrobial ly 118 susceptibility testing confirmed in vitro sensitivity to amikacin, cephotaxime, ceftiofur, ceftriaxone, 119 doxycycline, enrofloxacin, erythromycin, gentamicin, rifampin and trimethoprim-sulfamethoxazole. 120 Therapeutic plan and follow up 121 Following the first surgery the patient received systemic sodium penicillin (22,000 IU/kg bwt i.v. q. 122 6 h) and gentamicin (6.6 mg/kg bwt i.v. q. 24 h) for 4 days, which was changed to doxycycline8 (10 123 mg/kg bwt per os q. 24 h) when the susceptibility testing was available. Initially, anti-inflammatory 124 treatment consisted of phenylbutazone (4.4 mg/kg bwt i.v. q. 12 h) for 3 days, followed by 6 Equine Veterinary Education Page 8 of 25 125 suxibuzone7 (3.3 mg/kg btw i.v. q. 12 h) for 8 days. Another dose of morphine (0.1 mg/kg bwt i.m.) 126 was administered post-operatively. 127 Fluid therapy with isotonic solution, Ringer Lactate2 (10 L), supplemented with calcium 128 borogluconate2 23% (4 mEq/L) was administered overnight. Then enteral fluids with water 129 supplemented with sodium chloride9 (135 mEq/L), potassium chloride9 (5 mEq/L) and honey, as a 130 source of glucose, (15 ml/L) at a rate of 2 ml/kg/h for 7 days, was administered through a 5 mm 131 diameter nasogastric tube left in place sutured to the alar fold. 132 The mouth was flushed with water after doxycycline administration and diluted clorhexidine10 as an Fo 133 oral antiseptic. Ten milliliters of throat spray consisting of nitrofurazone11 (100 g), dexamethasone12 134 (6 ml, 2 mg/ml) and dimethyl sulfoxide9 (33 ml) was administered twice a day. On day 4, the mare r 135 was gradually fed, which she tolerated well. During hospitalization, the mare gradually improved, Re 136 nasal discharge and secretion from the tracheotomy site decreased. The tracheostomy tube was 137 removed 3 days after the second surgery and a wound dressing gauze was applied over the defect. vi 138 The tracheostomy, pharyngotomy, and submandibular incisions healed well by second intention. ew 139 On day 9 post-operatively, endoscopy revealed mild swelling of the soft palate and epiglottis. No 140 adhesions were observed between the epiglottis and subepiglottic fold. The patient was discharged On 141 on day 10. Doxycycline was continued for 3 weeks as well as oral flushing with diluted 142 clorhexidine after doxycycline administration. The mare was treated with suxibuzone and throat ly 143 spray for 1 week. Pharyngotomy and tracheotomy incisions were cleaned as needed. 144 On re-examination 3 weeks later, incisions healed uneventfully and plasma fibrinogen 145 concentration had decreased to 400 mg/dl. On upper airway endoscopy at that time the soft palate 146 was still dorsally displaced. Intermittent movement of the tip of the epiglottis over the soft palate 147 and lateralization was recognized. Food material was present in the nasal cavity and mucous 148 secretions in the trachea. Doxycycline was continued for an additional 2 weeks. 149 On a recheck two months later, total protein and fibrinogen had increased to 9 g/dl and 500 mg/dl 150 respectively. Surgical incisions and the tracheotomy site were not visible. On external palpation of 7 Page 9 of 25 Equine Veterinary Education 151 the pharynx, a 5 cm mass was evident on the right side of the tongue. Dorsal displacement of the 152 soft palate was still seen on endoscopy. Delineation of the mass by intraoral endoscopy was not 153 possible, but mild mucosal ulcerations on the surface of the mass were still observed. Therapy with 154 doxycycline was discontinued as no significant improvement was observed; trimethoprim- 155 sulfamethoxazole13 (30 mg/kg bwt per os q. 12 h) and potassium iodide9 (30 mg/kg bwt per os q24 156 h) was initiated for one week followed by potassium iodide at 20 mg/kg per os q24h for 3 weeks. 157 Iodides were chosen as these have been used for treatment of chronic or encapsulated bacterial 158 infections. Potassium iodide was to be discontinued if epiphora or skin exfoliation were observed. Fo 159 The owners were informed this condition could progress and the aim after the surgical resection 160 was to prevent regrowth of the remaining oropharyngeal mass. The mare was discharged with r 161 instructions to reexamine her in our hospital in 3-4 weeks, and phone call check-ups every two Re 162 weeks. 163 Outcome vi 164 The initial response to this treatment was satisfactory; the mare did not lose weight and had a good ew 165 quality of life. However, approximately 18 months after discharge from the hospital the mare was 166 euthanized due to progressive weight loss, progressive dysphagia and secondary aspiration On 167 pneumonia. Postmortem examination could not be performed at the farm. ly 8 Equine Veterinary Education Page 10 of 25 168 Discussion 169 Botryomycosis is a pyogranulomatous inflammation associated with eosinophilic granules that have 170 peripheral club formation, Splendor-Hoeppli phenomenon, and gram-positive cocci or gram- 171 negative bacilli (Speirs et al. 1971). S. aureus is the most common isolated bacteria. Occasionally, 172 other species such as E. coli, Proteus, Streptococcus, Pseudomona spp., Bacteroides and 173 Micrococcus spp. have been implicated (Winslow 1959, Akiyama 1996, Bonifaz and Carrasco 174 1996). It has also been reported under different names such as staphylococcal actinophytosis, 175 granular bacteriosis, actinobacillosis, bacterial pseudomycosis, bacterial granuloma and Fo 176 staphylococcal pseudomycetoma (Saadat et al. 2007, Scott 2007, Smiet et al 2012). 177 The occurrence of botryomycosis is rare in horses. It can be divided into cutaneous and visceral r 178 forms. (Winslow 1959, Smiet et al 2012). The most common presentation is as a staphylococcal Re 179 wound infection (Miller et al. 2001) especially after castration (Knottenbelt 2009) and occasionally 180 in tissues and skin of the mammary gland (Smiet et al. 2012). Diagnosis is made on the basis of vi 181 clinical signs and by histologic characteristics. One of the histological characteristics in ew 182 botryomycosis is the identification of the Splendor-Hoeppli (SH) phenomenon (Schlossberg et al. 183 1998, Snowden et al. 2003, Hussein 2008). It usually appears as strongly eosinophilic amorphous On 184 material with star-like or club-shaped configurations surrounding or adjacent to the causative agent. 185 The exact nature of the Splendore-Hoeppli reaction is not well understood yet. It represents a ly 186 localized immunological host reaction to antigens, in our case to Staphylococcus aureus (Saadat et 187 al. 2007, Hussein 2008, Rath et al. 2012). The extensive fibrotic and granulomatous lesion that 188 characterizes botryomycosis hinders diffusion of antimicrobials into the site of infection, and the 189 Splendore-Hoeppli material probably prevents phagocytosis and intracellular killing of the insulting 190 agent resulting in chronicity of the infection (Hussein 2008). 191 It is important to consider that sometimes the typical histological characteristics of botryomycosis 192 may be not identified. Atypical presentations with uncharacteristic lesions resembling other 193 conditions have been identified in humans. SH phenomenon was not identified in botryomycosis 9 Page 11 of 25 Equine Veterinary Education 194 patients with concurrent acquired immunodeficiency disease (Brunken et al. 1983, Patterson et al. 195 1987, Coulibaly et al 2008). Therefore, culture plays a significant role in the definitive diagnosis 196 and management of the patient. 197 Computed tomography and magnetic resonance imaging would have been key to define the extent 198 of the lesion and involvement of surrounding structures. Both diagnostic imaging techniques were 199 offered to the owner, but these were only available at a distant referral hospital and the owner 200 refused to perform them. 201 In the differential diagnosis of an oro-pharyngeal mass the conditions that should be considered are Fo 202 fungal granulomas, bacterial abscess, foreign body penetration, amyloidosis and neoplasia. Most of 203 the granulomas described in previous reports affecting the nasal passages, nasopharynx and r 204 oropharynx are associated with fungus (Hodgin and Conaway 1984). The conditions identified are Re 205 phycomycosis (Miller and Campbell 1982, Zamos et al. 1996), cryptococcosis (Watt 1970, Carrig 206 1968 Roberts et al. 1981, Malik et al. 1997, Stewart et al. 2009, Cruz et al. 2009), and granulomas vi 207 by Pseudallescheria spp. (Brearley et al. 1986), or Cocciodes spp. (Hodgin and Conaway 1984) ew 208 In a study of clinical observations of equine phycomycosis, the horses usually presented with a 209 large granulomatous nasal mass, nasal discharge, and dyspnea due to mechanical blockage (Miller On 210 and Campbell 1982). In the case described in this report, the mass in the oropharynx was 211 responsible for the loss of normal anatomy in the nasopharynx. In addition, the mass occluded the ly 212 end of the oropharynx, which resulted in dysphagia, dyspnea and nasal discharge. Likewise, the 213 case reports of cryptococcal granulomas in the nasal cavity with involvement of the nasopharynx 214 presented with anorexia, fever, inspiratory and expiratory difficulties, dyspnea, and malodorous 215 sanguineous or mucopurulent nasal discharge. On endoscopy, cryptococcal granulomas can be 216 identified as pale yellow, mucous-covered masses (Watt 1970, Carrig 1968 Roberts et al. 1981, 217 Malik et al. 1997, Stewart et al. 2009, Cruz et al. 2009). Considering the importance of climate 218 factors, such as warmth and humidity (Roberts et al. 1981), Spain does not provide the ideal 10 Equine Veterinary Education Page 12 of 25 219 environment for development of these mycosis and we considered these very unlikely as a possible 220 diagnosis in this mare. 221 Neoplasia of the larynx and pharynx in horses can include squamous cell carcinoma (Jones 1994), 222 lymphosarcoma (Burba et al. 1991), fibroma (Madewell 1976, Cotchin 1977) and melanoma (Dorn 223 and Priester 1976). Squamous cell carcinoma represents the most frequent neoplasm of the upper 224 respiratory and gastrointestinal tracts (Jones 1994). 225 Botryomycosis has a slow progression. The pathogenesis of botryomycosis has been discussed and 226 is not clearly understood. Host factors such as altered immune factors, debilitating illnesses, or Fo 227 concurrent infections are prerequisites to the development of the disease (Brunken et al. 1983). 228 Botryomycosis has been reported in patients with lowered resistance, immune deficiency or r 229 immunosuppression. In the case described, the mare was healthy but aged. For cryptococcosis, Re 230 damaged tissue that predisposes to infection has been suggested as a contributing factor (Roberts et 231 al. 1981, Cruz et al. 2009). For example, passage of a nasogastric tube or floating teeth could allow vi 232 the development of a scaffold for the organism. Because of the development of the mass in the ew 233 oropharynx, we hypothesize that an insult in the area could have been the beginning of the process. 234 However, this case had no history of lingual and oro-pharyngeal trauma or associated periodontal On 235 disease, therefore the source of infection could not be established. 236 Treatment of botryomycosis includes surgical excision combined with systemic antimicrobial ly 237 therapy. Effective treatment of botryomycosis depends on the nature of the inciting organism, the 238 site of lesion, and the horse’s immune status (Saadat et al. 2007). In the case described, because of 239 the poor accessibility of the mass, its hard and fibrotic consistency and the infiltrative nature of its 240 attachment to underlying tissues the resection was not completely achieved. Endoscopically-guided 241 diode laser excision combined with an oral approach may have resulted in a higher degree of 242 success. Surgical approach to lesions at the base of the tongue is somewhat limited unless 243 aggressive midline submandibular approaches are used. Intraoral approaches provide limited 244 exposure to subepiglotic and aboral tongue structures. Similarly, a ventral midline pharyngotomy 11 Page 13 of 25 Equine Veterinary Education 245 only provides limited access to structures below the soft palate and epiglottis. In addition the mass 246 was located far too orally in order to be accessed by a laringotomy approach. 247 Antimicrobial therapy is impaired in cases of botryomycosis by the Splendore-Hoeppli reaction that 248 appears to prevent achieving bactericidal antibiotic concentrations inside the granuloma. It may also 249 prevent phagocytosis and intracellular killing of the bacteria and thus influence treatment (Saadat et 250 al. 2007, Smiet et al 2012). In the case described, the choice of antibiotic therapy was based on 251 culture and susceptibility results. 252 Potassium iodide has been the treatment of choice for Sporotrichosis (Rosser et al. 1981, Werner Fo 253 and Werner 1994) and is commonly used in treatment of fungal infections in horses (Zamos et al. 254 1996, Davis et al. 2000, Schwarz et al. 2009, Crothers et al. 2009). Review of the existing literature r 255 revealed that potassium iodide (KI) has not been reported previously as a therapeutic option for Re 256 botryomycosis. We introduced it following the recommendation of a veterinary colleague 257 (Knottenbelt 2013). Iodides have traditionally been used in selected cases for treatment of chronic vi 258 or well encapsulated bacterial or fungal infections. Iodides are anti-inflammatory agents by virtue ew 259 of their ability to quench toxic oxygen metabolites and inhibit neutrophil chemotaxis.(Sterling and 260 Heyman 2000). Side effects during treatment may include epiphora, ocular discharge, cough, and On 261 dry seborrhea of the skin and coat (Davis et al. 2000, Knottenbelt 2002). No adverse effects were 262 noted in the case described here. ly 263 Research into S. aureus abscess formation and persistence in host tissue has demonstrated that 264 different surface proteins involved in disease pathogenesis may be useful for vaccine development 265 in the future and provide a new line of treatment (Cheng et al. 2009). 266 We have described the first report of chronic botryomycosis in equine presented as an 267 oropharyngeal mass, which is comparable with similar masses in other parts of the body. The slow 268 onset of clinical signs and difficulty in visualization and/or recognizing this abnormality may allow 269 significant enlargement and extensive tissue invasion to occur prior to presentation for examination 270 and treatment. In conclusion, oropharyngeal botryomycosis should be distinguished from other 12 Equine Veterinary Education Page 14 of 25 271 conditions in the horse, which are characterized, by mucopurulent nasal discharge, airway 272 obstruction, respiratory noise, dyspnea, and dysphagia. Fo r Re vi ew On ly 13 Page 15 of 25 Equine Veterinary Education 273 Authors’ declaration of interest 274 No conflicts of interest have been declared. 275 276 Source of funding 277 None. Fo r Re vi ew On ly 14 Equine Veterinary Education Page 16 of 25 278 Manufacturers’ addresses 1 279 Laboratorios ERN S.A., Barcelona, Spain. 2 280 B. Braun Vet Care, Rubi, Barcelona, Spain. 3 281 Zoetis, Alcobendas, Madrid, Spain. 4 282 Boehringer Ingelheim, Sant Cugat del Vallès, Barcelona, Spain. 5 283 Merial Laboratorios, Barcelona, Spain. 6 284 Roche, Sant Cugat del Vallès, Barcelona, Spain. 7 285 Laboratorios Dr. Esteve, Martorelles, Barcelona, Spain. Fo 8 286 Laboratorios Syva S.A.U., León, Spain. 9 287 Fragon Iberica S.A.U., Terrasa, Barcelona, Spain. r 10 288 AGB, Ajalvir, Madrid, Spain. Re 11 289 Laboratorios Seid, Lliça de Vall, Barcelona, Spain. 12 290 Schering-Plough Animal Health, San Agustín de Guadalix, Madrid, Spain. vi 13 291 Fatro Ibérica, Sant Just Desvern, Barcelona, Spain. ew On ly 15 Page 17 of 25 Equine Veterinary Education 292 References 293 Akiyama, H., Kanzaki, H., Tada, J. and Arata, J. (1996) Staphylococcus aureus infection on cut 294 wounds in the mouse skin: experimental staphylococcal botryomycosis. J Dermatol Sci. 11, 234- 295 238. 296 Bollinger, O. (1870) Mycosis der Lunge beim Pferde. Virchows. Arch Pathol Anat. 49, 583-6. 297 Bonifaz, A. and Carrasco, E. (1996) Botryomycosis. Int. J. Dermatol. 35, 381-388. 298 Bostrom, R.E., Huckins, J.G., Kroe, D.J., et al. (1969) Atypical fatal pulmonary botryomycosis in 299 two guinea pigs due to Pseudomonas aeruginosa. J Am Vet Med Assoc. 155, 1195-9. Fo 300 Boulton, C.H., Williamson, L. (1984) Cryptococcal granuloma associated with jejunal 301 intussusception in a horse. Equine Vet J. 16, 548-551. r 302 Brearley, J.C., McCandlish, I.A., Sullivan, M., Dawson, C.O. (1986) Nasal granuloma caused by Re 303 Pseudallescheria boydii. Equine Vet J. 18, 151-3. 304 Brunken, R.C., Lichon-Chao, N., Van der Broek, H. (1983) Immunologic abnormalities in vi 305 botryomycosis. A case report with review of the literature. J Am Acad Dermatol. 9, 428-34. ew 306 Burba, D.J., Jann, H.W., Confer, A.W. (1991) Surgical reduction of a laryngeal lymphosarcoma 307 mass causing dyspnea in a horse. Equine Pract. 13, 14-6. On 308 Carrig, C.B. (1968) What is your diagnosis? J Am Vet Med Assoc. 153, 1206-9. 309 Casamián-Sorrosal, D., Fournier, D., Shippam, J., Woodward, B. and Tennant, K. (2008) Septic 310 pericardial effusion associated with pulmonary and pericardial botryomycosis in a dog. J Small ly 311 Anim Pract. 49, 655-659. 312 Cheng, A.G., Kim, H.K., Burts, M.L., Krausz, T., Schneewind, O. and Missiakas, D.M. (2009) 313 Genetic requirements for Staphylococcus aureus abscess formation and persistence in host tissues. 314 Faseb J. 23, 3393-3404. 315 Coulibaly, B., Géraldine, H., Le Hémon, A., Gouriet, F. and Marie-Anne, C. (2008) Staphylococcus 316 aureus isolated from a case of lymph node botryomycosis. Arch Pediatr. 15, 1440-1442. 317 Cotchin, E. (1977) A general survey of tumors in the horse. Equine Vet J. 9, 16-21. 16 Equine Veterinary Education Page 18 of 25 318 Cruz, V.C., Sommardahl, C.S., Chapman, E.A., Fry, M.M., Schumacher, J. (2009) Successful 319 treatment of a sinonasal cryptococcal granuloma in a horse. J Am Vet Med Assoc. 234, 509-513. 320 Crothers, S.L., White, S.D., Ihrke, P.J., Affolter, V.K. (2009) Sporotrichosis: a retrospective 321 evaluation o 23 cases seen in northern California (1987-2007). Vet Dermatol. 20, 249-59. 322 Davis, P.R., Meyer, G.A., Hanson, R.R., Stringfellow, J.S. (2000) Pseudallescheria boydii infection 323 of the nasal cavity of a horse. J Am Vet Med Assoc. 217, 707-9. 324 Dorn, C.R., Priester, W.A. (1976) Epidemiologic analysis of oral and pharyngeal cancer in dogs, 325 cats, horses and cattle. J Am Vet Assoc 169. 1202-5. Fo 326 Hussein, M.R. (2008) Mucocutaneous Splendore-Hoeppli phenomenon. J Cutan Pathol. 35, 979- 327 988. r 328 Jones, D.L. (1994) Squamous cell carcinoma of the larynx and pharynx in horses. (1994) Cornell Re 329 Vet. 84, 15-24. 330 Kiper ML, Wrigley R, Traub-Dargatz J, Bennett D. (1992) Metallic foreign bodies in the mouth or vi 331 pharynx of horses: seven cases (1983-1989). J Am Vet Med Assoc. 200(1):91-3. ew 332 Knottenbelt, D.C. (2002) Fungal airways diseases. In: Equine Respiratory Diseases. Ithaca, NY: 333 International Veterinary Information Service (www.ivis.org). 334 Knottenbelt, D.C. (2009) Bacterial granuloma (botryomycosis / staphylococcal pseudomycetoma / On 335 deep pyoderma). In: Pascoe’s Principles and Practice of Equine Dermatology, 2nd edn., Ed: D.C. 336 Knottenbelt, Saunders Elsevier, Edinburgh. pp 148-150. ly 337 Knottenbelt, D.C. (2013) Personal communication. 338 Madewell, B.R., Priester, W.A., Gillete, E.L., Snyder, S.P. (1976) Neoplasms of the nasal passages 339 and paranasal sinuses in domesticated animals as reported by 13 veterinary colleges. Am J Vet Res. 340 37, 851-5. 341 Malik, R., Martin, P., Wigney, D.I., Church, D.B., Bradley, W., Bellenger, C.R., Lamb, W.A., 342 Barrs, V.R., Foster, S., Hemsley, S., Canfield, P.J., Love, D.N. (1997) Nasopharyngeal 343 cryptococcosis. Aust Vet J. 75, 483-8. 344 Miller, R.I., Campbell, R.S.F. (1982) Clinical observations on equine phycomycosis. Aust Vet J. 345 58, 221-6. 17 Page 19 of 25 Equine Veterinary Education 346 Miller, M.A., Fales, W.H., Tyler, J.W., Suedmeyer, W.K. (2001) Pulmonary botryomycosis in a 347 Scottish Highland steer. J Vet Diagn Invest. 13, 74-76. 348 Orhan, D., Kiratli, H., Kocabeyoglu, S. (2006) Conjunctival Splendore-Hoeppli phenomenon in a 3- 349 year-old child. Pediatr Dev Pathol. 9, 388. 350 Pandey, G.S., Nomura, Y., Kobayashi, K., Fujise, H., Yamada, T. (1998) Cutaneous staphylococcal 351 granuloma in a free living zebra (Equus burchelli) in Zambia. J Vet Med Sci. 60, 137-8. 352 Patterson, J.W., Kitces, E.N., Neafie, R.C. (1987) Cutaneous botryomycosis in a patient with 353 acquired immunodeficiency syndrome. J Am Acad Dermatol. 16, 238-42. Fo 354 Rath, S., Sharma, S., Mohapatra, S., Roy, A., Vemuganti, G.K., Balne, P., Reddy, A. (2012) Mixed 355 Nocardia cyriacigeorgica and Staphylococcus aureus infection in the periocular skin and orbit in an 356 immunocompetent adult. Orbit 31, 428-30. r Re 357 Roberts, M.C., Sutton, R.H., Lovell, D.K. (1981) A protracted case of cryptococcal nasal 358 granuloma in a stallion. Aust Vet J. 57, 287-291. vi 359 Rosser, E.J., Dunstan, R.W. (1998) Sporotrichosis. In: Greene CE, ed. Infectious Diseases of the 360 Dog and Cat, 2nd edn. Philadelphia, PA: W.B. Saunders Co., 399-402. ew 361 Saadat, P., Ram, R., Sohrabian, S. and Vadmal, M. (2007) Botryomycosis caused by 362 Staphylococcus aureus and Pneumocystis carinii in a patient with acquired immunodeficiency On 363 disease. Clin. Exp. Dermatol. 33, 266-269. 364 Schlossberg, D., Pandey, M. and Reddy, R. (1998) The Splendore-Hoeppli phenomenon in hepatic 365 ly botryomycosis. J Clin Pathol. 51, 399-400. 366 Scott, D.W. (2007) Cutaneous bacterial pseudomycetoma (botryomycosis) in dogs: Two new case 367 reports and a review of the literature. Jpn J Vet Dermatol. 13, 135-140. 368 Shaw, D.P., Gunson, D.E., Evans, L.H. (1987) Nasal Amyloidosis in Four Horses. Vet Pathol. 24, 369 183-5. 370 Schwarz B, Burford J, Knottenbelt D. Cutaneous fungal granuloma in a horse. (2009) Vet 371 Dermatol. 20, 131-4. 372 Sheikh-Omar, A.R. and Abdullah, A.S. (1985) Perforated gastric ulcer associated with disseminated 373 staphylococcal granuloma (botryomycosis) in a cat. Vet Rec. 117, 131. 18 Equine Veterinary Education Page 20 of 25 374 Sleeman, J., Clyde, V., Finnegan, M., Ramsay, E. and Shires, M. (2003) Mammary botryomycosis 375 and mastectomy in an African elephant (Loxodonta africana). Vet. Rec. 152, 54-55. 376 Smiet, E., Grinwis, G. C. M., van den Top, J. G. B., Oldruitenborgh-Oosterbaan, M. M. S. (2012) 377 Equine mammary gland disease with a focus on botryomycosis: A review and case study Equine 378 vet. Educ. 24, 357-366. 379 Snowden, M.J., McAlindon, T.E., Morosan, C.G., Lo, G.H. (2006) Small vessel vasculitis in a 380 patient with botryomycosis. J Rheumatol, 33, 2545. 381 Speir, W.A., Mitchener, J.W., Galloway, R.F. (1971) Primary pulmonary botryomycosis. Chest 60, 382 92-93. Fo 383 Sterling JB, Heymann WR. (2000) Potassium iodide in dermatology: a 19th century drug for the 384 21st century-uses, pharmacology, adverse effects, and contraindications. J Am Acad Dermatol. r 385 43(4):691-7. Re 386 Stewart, A.J., Salazar, T., Waldridge, B.M., Schumacher, J., Welles, E.G., Hanson, R.R., Sartin, 387 E.A., Lenz, S.D., Holland, M., Beard, D.M. (2009) Multimodal treatment of recurrent sinonasal vi 388 cryptococcal granulomas in a horse. J Am Vet Med Assoc. 235, 723-730. ew 389 Watt, D.A. (1970) A case of cryptococcal granuloma in the nasal cavity of a horse. Aust Vet J. 46, 390 493-5. On 391 Werner, A.H., Werner, B.E. (1994) Sporotrichosis in man and animal. International Journal of 392 Dermatology. 33, 692-700. 393 ly Winslow, D.J. (1959) Botryomycosis. Am J Pathol. 35, 153-167. 394 Zamos, D.T., Schumacher, J., Loy, J.K. (1996) Nasopharyngeal conidiobolomycosis in a horse. J 395 Am Vet Med Assoc. 208, 100-1. 396 19 Page 21 of 25 Equine Veterinary Education 397 Figure Legends 398 Fig 1: Ultrasonographic examination of the oropharyngeal mass to the right of midline. A well- 399 encapsulated mass with puntiform hyperechoic structures and mineral opacities with interspersed 400 hypoechoic areas is observed. The mass was approximately 2 × 2.6 cm. 401 Fig 2: Endoscopy of the nasopharynx; dorsal displacement of the soft palate is observed (A) due to 402 swelling underneath the soft palate that obliterates the view of the larynx. Endoscopy of the 403 oropharynx, an ulcerated subepiglotic mass is identified partially obscuring the epiglottis (B). 404 Fig 3: Endoscopy of the nasopharynx; reminiscence of the mass attached to the aryepiglottic fold 405 (black arrows) obstructing the entrance to the trachea and persistent dorsal displacement of the soft Fo 406 palate. Nasogastric tube for enteral fluid therapy (white arrows) (A). A modified esophageal 407 grasping forceps with a horizontal jaw was used to grip the mass (B). r 408 Fig 4: Staphylococal pyogranuloma The pyogranuloma is constituted by a deeply eosinophilic Re 409 material (Splendore-Hoeppli phenomenon) and numerous cocoid bacterial colonies surrounded by 410 collections of degenerate neutrophils with variable numbers of surrounding macrophages and vi 411 epithelioid cells. HE staining (A). In a serial section it can be observed the Gram positive bacterial ew 412 colonies showing a deep blue staining. Gram stain (B). On ly 20 Equine Veterinary Education Page 22 of 25 Fo r Re vi ew Fig 1: Ultrasonographic examination of the oropharyngeal mass to the right of midline. A well-encapsulated mass with puntiform hyperechoic structures and mineral opacities with interspersed hypoechoic areas is observed. The mass was approximately 2 × 2.6 cm. 266x200mm (72 x 72 DPI) On ly Page 23 of 25 Equine Veterinary Education Fo r Fig 2: Endoscopy of the nasopharynx; dorsal displacement of the soft palate is observed (A) due to swelling underneath the soft palate that obliterates the view of the larynx. Endoscopy of the oropharynx, an Re ulcerated subepiglotic mass is identified partially obscuring the epiglottis (B). vi ew On ly Equine Veterinary Education Page 24 of 25 Fo r Fig 3: Endoscopy of the nasopharynx; reminiscence of the mass attached to the aryepiglottic fold (black arrows) obstructing the entrance to the trachea and persistent dorsal displacement of the soft palate. Re Nasogastric tube for enteral fluid therapy (white arrows) (A). A modified esophageal grasping forceps with a horizontal jaw was used to grip the mass (B). vi ew On ly Page 25 of 25 Equine Veterinary Education Fo r Re vi ew Fig 4: Staphylococal pyogranuloma The pyogranuloma is constituted by a deeply eosinophilic material (Splendore-Hoeppli phenomenon) and numerous cocoid bacterial colonies surrounded by collections of degenerate neutrophils with variable numbers of surrounding macrophages and epithelioid cells. HE staining (A). In a serial section it can be observed the Gram positive bacterial colonies showing a deep blue staining. Gram stain (B). On 903x677mm (72 x 72 DPI) ly Equine Veterinary Education Page 26 of 25 Fo r Re vi ew Fig 4: Staphylococal pyogranuloma The pyogranuloma is constituted by a deeply eosinophilic material (Splendore-Hoeppli phenomenon) and numerous cocoid bacterial colonies surrounded by collections of degenerate neutrophils with variable numbers of surrounding macrophages and epithelioid cells. HE staining (A). In a serial section it can be observed the Gram positive bacterial colonies showing a deep blue staining. Gram stain (B). On 903x677mm (72 x 72 DPI) ly