Diagnosis and treatment of truncal cutaneous pythiosis in a dog

Abstract

Aggressive surgical excision in combination with medical treatment resulted in a favorable long-term (> 1 year) outcome in this dog. Thorough workup including diagnostic imaging and lymph node evaluation is recommended. If surgery is to be performed, skin margins of 5 cm and deep margins of 2 fascial planes are recommended.

Successful management of cutaneous pythiosis in a dog with subsequent cutaneous vasculitis

“…Because local postoperative recurrence of pythiosis is common at the site of resection or in regional lymph nodes, the removal of draining lymph nodes, especially if enlarged, is also recommended (Grooters 2003, Schmiedt and others 2012). Often, Pythium species lesions located on the trunk need drastic resection with removal of multiple fascial planes and sometimes bone (Thieman and others 2011). …”

“…There are multiple factors that may have contributed to success in this case. First, we were able to surgically remove all grossly infected tissue, which is the most important goal of treatment (Grooters 2003, Thieman and others 2011). Complete removal of diseased tissue increases chances of success compared with medical management alone (Grooters 2003).…”

“…Pythium species organisms are not true fungi and lack a cell wall, so classic antifungal medications such as the azoles and terbinafine that inhibit ergosterol production are not expected to be highly efficacious (Gaastra and others 2010). The combination of itraconazole at 10 mg/kg and terbinafine at 30 mg/kg is most often recommended (Grooters 2003, Thieman and others 2011, Oldenhoff and others 2014). While the innovator formula Sporanox has long been considered the gold standard, the expense is a limiting factor for its use.…”

“…The infection occurs mainly in tropical and subtropical areas, and depending on the site of entry, infection can lead to cutaneous, gastrointestinal, or less commonly vascular, ocular or systemic forms of disease (Gaastra and others 2010). The disease usually has a grave prognosis with infection recurrence common (Dykstra and others 1999), although success can be seen with aggressive surgical resection combined with long‐term medical management (Grooters 2003, Thieman and others 2011). The case presented here is an example of successfully managed cutaneous pythiosis with an additional point of interest manifested as cutaneous vasculitis during treatment.…”

History and Perspective of Immunotherapy for Pythiosis

“…Biflagellate zoospore is an infective stage of P. insidiosum that shows strong tropism to animal hairs and tissues [41,42]. Direct exposure to the pathogen habitat (i.e., stagnant water, rice field, pond) could increase the risk of the infection [43][44][45][46][47]. Patients with pythiosis usually manifest with clinical features associated with an infection of the skin [11,23,48,49], artery [13,50,51], eye [47,[52][53][54], gastrointestinal tract [28,[55][56][57], or another internal organ [5,12,[58][59][60].…”