Evaluating the efficacy of surgical excision and topical dimethyl sulphoxide (DMSO) in the treatment of equine cutaneous pythiosis

Document Type : Full paper (Original article)


1 Department of Surgery, Anesthesiology and Radiology, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh 33516, Egypt

2 Department of Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt


Background: Cutaneous pythiosis in horses is a chronic ulcerative granulomatous disease caused by the oomycete Pythium insidiosum. Aims: The objective of the present study was to evaluate the response of cutaneous pythiosis in horses to surgical excision and topical dimethyl sulphoxide (DMSO). Methods: Thirty horses were presented clinically with pruritus, fistulae discharging serosanguineous fluid, and output kunkers in different body areas (limb, abdomen, neck, and face). The clinical diagnosis was confirmed by isolation of the causative agent and histopathology. All animals were treated by surgical excision alone, or surgical excision followed by topical DMSO. The healing process was monitored every week macroscopically to evaluate the response to treatment until complete recovery. Results: The existence of Pythium insidiosum was confirmed in all cases. Histologically, affected horses were characterized by granulation tissue with abundant eosinophils. The size of wounds and the clinical features of pythiosis lesions decreased more after surgical debridement with DMSO application than surgical excision alone. The cutaneous pythiosis lesions were completely recovered at 35 ± 7 and 60 ± 5 days after the surgical excision with topical DMSO and surgical excision alone, respectively. Conclusion: The combination of surgical excision and topical DMSO is found an effective treatment for cutaneous pythiosis in horses.


Main Subjects

Atiba, A and Ghazy, A (2015). The effects of topical dimethyle sulfoxide on second-degree burn wound healing in dogs. A. J. Vet. Sci., 45: 6-12.
Cafarchia, C; Figueredo, LA and Otranto, D (2013). Fungal diseases of horses. Vet. Microbiol., 167: 215-234.
Capriotti, K and Capriotti, JA (2012). Dimethyl sulfoxide: History, chemistry, and clinical utility in dermatology. J. Clin. Aesthet. Dermatol., 5: 24-26.
Cardona-Alvarez, J; Vargas-Vilória, M and Patarroyo-Salcedo, J (2017). Pythiosis cutaneous in horses treated with triamcinolone acetonide. Part 2. Histological and histochemical description. Rev. MVZ. Cordoba. 22: 5638-5652.
Carvalho, ADM; Munhoz, TCP; Toma, HS; dos Santos, JPV; de Oliveira, LGS; Boabaid, FM; Xavier, AB and Kommers, GD (2019). The use of fluconazole associated with surgical excision in the treatment of equine cutaneous pythiosis. Semin. Agrar., 40: 3079-3088.
Chaffin, MK; Schumacher, J and McMullan, WC (1995). Cutaneous pythiosis in the horse. Vet. Clin. North Am. Equine Pract., 11: 91-103.
Chitasombat, MN; Jongkhajornpong, P; Lekhanont, K and Krajaejun, T (2020). Recent update in diagnosis and treatment of human pythiosis. Peer J., 8: 1-30.
Dias, DPM; Doria, RGS; Pereira, RN; Canola; PRA and Di Filippo, PA (2012). Topical treatment using Amphotericin B and DMSO for an atypically located equine cutaneous pythiosis. Acta Sci. Vet., 40: 75-78.
Doria, RGS; Carvalho, MB; Freitas, SH; Laskoski, LM; Colodel, EM; Mendonca, FS; Silva, MAG; Grigoletto, R and Neto, PF (2015). Evaluation of intravenous regional perfusion with amphotericin B and dimethylsulfoxide to treat horses for pythiosis of a limb. BMC Vet. Res., 11: 1-7.
Doria, RGS; Freitas, SH; Linardi, RL; Mendonca, FD; Arruda, LP; Boabaid, FM and Valadao, CA (2012). Treatment of pythiosis in equine limbs using intravenous regional perfusion of Amphotericin B. Vet. Surg., 41: 759-765.
Duimel-Peeters, IGP; Houwing, RH; Teunissen, CP; Berger, MPF; Snoeckx, LHEH and Halfens, RJG (2003). A systematic review of the efficacy of topical skin application of dimethyl sulfoxide on wound healing and as an anti-inflammatory drug. Wounds. 15: 361-370.
Elkhenany, H; Nabil, S; Abu-Ahmed, H; Mahmoud, H; Korritum, A and Khalifa, H (2019). Treatment and outcome of horses with cutaneous pythiosis, and meta-analysis of similar reports. Slov. Vet. Res., 56: 281-291.
Gaastra, W; Lipman, LJA; De Cock, AWAM; Exel, TK; Pegge, RBG; Scheuwater, J; Vilela, R and Mendoza, L (2010). Pythium insidiosum: An overview. Vet. Microbiol., 146: 1-16.
Grooters, AM (2013). Pythiosis and zygomycosis. In: Sellon, DC and Long, MT (Eds.), Equine infectious diseases. (2nd Edn.), St Louis, Saunders Elsevier. PP: 415-421.
Hassan, AS (2014). The antibacterial activity of dimethyl sulfoxide (dmso) with and without of some ligand complexes of the transitional metal ions of ethyl coumarin against bacteria isolate from burn and wound infection. J. Nat. Sci. Res., 4: 106-111.
Leal, ABM; Leal, AT; Santurio, JM; Kommers, GD and Catto, JB (2001). Equine pythiosis in the Brazilian Pantanal region: Clinical and pathological findings of typical and atypical cases. Pesqui. Vet. Bras., 21: 151-156.
Lerksuthirat, T; Sangcakul, A; Lohnoo, T; Yingyong, W; Rujirawat, T and Krajaejun, T (2017). Evolution of the sterol biosynthetic pathway of Pythium insidiosum and related oomycetes contributes to antifungal drug resistance. Antimicrob. Agents Chemother., 61: 1-14.
Loreto, ES; Alves, SH; Santurio, JM; Nogueira, CW and Zeni, G (2012). Diphenyl diselenide in vitro and in vivo activity against the oomycete Pythium insidiosum. Vet. Microbiol., 156: 222-226.
Loreto, ES; Tondolo, JS; Pilotto, MB; Alves, SH and Santurio, JM (2014). New insights into the in vitro susceptibility of Pythium insidiosum. Antimicrob. Agents Chemother., 58: 7534-7537.
Mendoza, L; Mandy, W and Glass, R (2003). An improved Pythium insidiosum-vaccine formulation with enhanced immunotherapeutic properties in horses and dogs with pythiosis. Vaccine. 21: 2797-2804.
Mosbah, E; Karrouf, GIA; Younis, EA; Saad, HS; Ahdy, A and Zaghloul, AE (2012). Diagnosis and surgical management of pythiosis in draft horses: report of 33 cases in Egypt. J. Equine Vet. Sci., 32: 164-169.
Randhawa, MA (2006). The effect of dimethyl sulfoxide (DMSO) on the growth of dermatophytes. Japanese J. Med. Mycol., 47: 313-318.
Randhawa, MA (2008). Dimethyl sulfoxide (DMSO) inhibits the germination of Candida albicans and the arthrospores of Trichophyton mentagrophytes. Japanese J. Med. Mycol., 49: 125-128.
Randhawa, MA; Hamad, S and Aljabre, M (2007). Dimethyl sulfoxide (DMSO) has an additive effect and alters minimal inhibitory concentrations of antifungal drugs. J. Rawalpindi. Med. Coll., 11: 54-60.
Rivierre, C; Laprie, C; Guiard-Marigny, O; Bergeaud, P; Berthelemy, M and Guillot, J (2005). Pythiosis in Africa. Emerg. Infect. Dis., 11: 479-481.
Romero, A; Garcia, J; Balestie, S; Malfatto, F; Vicentino, A; Sallis, ESV; Schild, AL and Dutra, FQ (2019). Equine pythiosis in the Eastern wetlands of Uruguay1. Pesqui. Vet. Bras., 39: 469-475.
Santos, CEP; Ubiali, DG; Pescador, CA; Zanette, RA; Santurio, JM and Marques, LC (2014). Epidemiological survey of equine pythiosis in the Brazilian pantanal and nearby areas: Results of 76 cases. J. Equine Vet. Sci., 34: 270-274.
Tarrand, JJ; LaSala, PR; Han, XY; Rolston, KV and Kontoyiannis, DP (2012). Dimethyl sulfoxide enhances effectiveness of skin antiseptics and reduces contamination rates of blood cultures. J. Clin. Microbiol., 50: 1552-1557.