Treatment of pythiosis in equine limbs using intravenous regional perfusion of amphotericin B.
Authors: Dória Renata G S, Freitas Silvio H, Linardi Renata L, Mendonça Fábio de Souza, Arruda Laura P, Boabaid Fabiana M, Valadão Carlos A A
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Amphotericin B Regional Perfusion for Equine Pythiosis Pythium insidiosum infection in horses presents a significant clinical challenge, particularly in the distal limbs where systemic antifungal therapy penetrates poorly. This case series of 12 horses evaluated intravenous regional limb perfusion (IRLP) of amphotericin B following surgical debridement and thermocautery, administering 50 mg via a catheter placed in a superficial vein distal to a tourniquet. Complete lesion resolution occurred in 92% of cases within 35–60 days after one or two treatment cycles, with clinical evaluations tracking improvement over two months. Whilst transient complications emerged—limb oedema and regional pain in 42% of horses and injection site inflammation in 33%—these adverse effects resolved spontaneously within a fortnight. For practitioners managing equine pythiosis, this technique offers a practical high-success strategy that delivers concentrated antifungal activity directly to the infection site whilst avoiding systemic toxicity, though combining IRLP with aggressive surgical management remains essential for optimal outcomes.
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Practical Takeaways
- •IRLP amphotericin B combined with surgical debridement and thermocautery offers a practical treatment option for equine pythiosis with high success rates and acceptable short-term side effects
- •Plan for temporary limb swelling and pain in the first two weeks post-treatment; these are expected and resolve without intervention
- •Consider this technique for distal limb pythiosis cases as an alternative to amputation or prolonged topical therapy
Key Findings
- •92% of horses achieved complete lesion resolution within 35-60 days after 1-2 intravenous regional limb perfusion (IRLP) treatments with amphotericin B
- •Limb edema and regional pain occurred in 42% of treated horses but resolved within 14 days
- •Injection site inflammation occurred in 33% of horses and also resolved within 14 days