Surgical excision and topical dimethyl sulphoxide (DMSO) for equine pythiosis

As described in the article treatment with regional perfusion of DMSO and antifungals was effective for treating pythiosis. Regional perfusion while not that difficult does require certain technical skills, probably a trip to the equine hospital. Here surgical excision in combination with plain DMSO was found to be curative. Personally, if I tried this route, I would try to find a safe concentration of antifungal to add to the DMSO and use this as my topical. However, the results are interesting suggesting an antifungal quality of the DMSO alone.
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Evaluating the efficacy of surgical excision and topical dimethyl sulphoxide (DMSO) in the treatment of equine cutaneous pythiosis
Iran J Vet Res. Fall 2020;21(4):301-307.
Authors
A Atiba 1 , A Ghazy 1 , M H Hamad 2
Affiliations

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.

Abstract

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.

Keywords: Dimethyl sulphoxide; Horse; Pythiosis; Pythium insidiosum; Surgical excision.