Texas Equine Veterinary Association

• 19 • Treatment of cutaneous habronemiasis requires 1) debridement of the lesions to remove excess granulation tissue and "sulfur" granules, 2) mitigation of local inflammation and 3) elimination of migrating larvae. ere are many treatments that can be used, but they all require the 3 components listed above. Debridement of the affected tissue serves several purposes. Physically removing viable larvae and inflamed tissue helps to decrease further larval migration. e "sulfur" granules will prevent a lesion from healing, so they must be removed to allow the wound to start healing with healthier tissue. Until aggressive debridement is done, the wound will never fully heal. ese lesions are not uncommonly treated by owners for weeks to months, before seeking veterinary intervention. Aggressive debridement is the key, and can not be overemphasized! Mitigation of local inflammation can be done locally or systemically. Triamcinolone is commonly injected into the lesion bed aer debridement. Many combinations of steroid-containing topical medications can lead to the desired decrease of the local inflammation. Systemic steroids can also be used to decrease inflammation, especially if there are multiple habronemiasis lesions. Elimination of migrating larvae may be the hardest goal to achieve with our current arsenal of anthelmintics. Resistance to ivermectin, and presumably moxidectin, has developed. is has led to an increase in difficulty with resolving lesions in the early stages. ese lesions, le unchecked, develop into extremely challenging medical management cases. Some of the resistant recurrent cases will only be healed for a few winter months before the process begins again in the warmer weather of the spring. ese are challenging for both veterinarian and owner. Realizing that there are many ways to treat these cases, I will outline my own personal choices for treatment. I will aggressively debride any excess or friable tissue by bluntly scraping the lesions with the handle end of a #4 blade handle. If necessary, I will sharply debride any tissue that is above the skin edge. If there are many sulfur granules, I will sharply debride any tissue that can be removed. I will systemically deworm with ivermectin (recommended per body weight oral dose: 200mcg/kg) once a week for 3–4 weeks. If the tissue is very inflamed and itchy, I will locally inject up to 10mg of triamcinolone aer debridement. I will also dispense a combination of phosmet (Paramite LA© dip- organophosphate), DMSO and dexamethasone (2mg/ml). I dispense this in a dauber bottle for use topically twice daily until the lesions are resolved. I mix the combination with equal parts of all 3 medications. • • • • • Figure 8: Sheath lesion that had been treated topically by the owner for 8 months Figure 9: Lesion 6 months aer aggressive debridement and treatment

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