Retrospective Evaluation of a Novel Sustained-Release Ivermectin Varnish for Treatment of Wound Myiasis in Zoo-Housed Animals

Abstract

Myiasis is a major disease condition in human and veterinary medicine. Domestic, free-ranging, and zoo-housed animals can be severely affected by myiasis. Depending on case severity, multiple treatment episodes may be indicated and can lead to recurrent capturing, handling stress, and anesthetics, all of which increase the risk of adverse responses (including death) individually and also in the herd. As an insecticide, ivermectin is often used for larval control. A total of 28 individual myiasis cases were retrospectively evaluated, out of which 11 cases were also treated using an ivermectin sustained-release varnish (SRV). The clinical outcome of all cases was assessed and the results suggest that the use of a topical ivermectin SRV (with or without concurrent injectable ivermectin) can reduce handling and treatments, has no adverse effects, and has minimal recurrence of the disease when compared with cases treated without it.

Time to consider pharmacological interventions against infectious disease in wildlife

“…Drugs requiring repeated administration are a major hindrance in wildlife medicine and have resulted in the development of delivery systems that significantly extend action (Avni-Magen et al, 2018). For example, replacing frequent subcutaneous ivermectin, a topical ivermectin sustained-release varnish was an efficacious single-dose treatment for myiasis in zoo-housed wildlife, including ungulate and avian species (Avni-Magen et al, 2018). Hydrogels, a group of gel-forming delivery systems, also show promise for prolonging therapeutic action, increasing efficacy and reducing toxicity (Coutant et al, 2019).…”

“…Improving the utility of existing PI agents by targeting their specific limitations is another pathway to success. Drugs requiring repeated administration are a major hindrance in wildlife medicine and have resulted in the development of delivery systems that significantly extend action (Avni‐Magen et al, 2018). For example, replacing frequent subcutaneous ivermectin, a topical ivermectin sustained‐release varnish was an efficacious single‐dose treatment for myiasis in zoo‐housed wildlife, including ungulate and avian species (Avni‐Magen et al, 2018).…”

Aspects in controlled drug delivery for topical applications in veterinary medicine

“…The varnish was applied from one to three days, with complete resolution of the lesions. More recently, efficacy of ivermectin varnish in the treatment of wound myiasis of various severity was assessed in a variety of zoo animals, and it has been demonstrated that the use of a topical ivermectin varnish (with or without concurrent injectable ivermectin) can reduce handling and treatments, had no detectable adverse effects, and had minimal recurrence of the disease when compared with cases treated without it ( Avni-Magen et al., 2018 ).…”

Neonatal Umbilical Myiasis - Our experience

“…It acts by causing the parasite's cell membrane to increase in permeability resulting in paralysis and death 24 . It has been widely used in cases of animal myiasis successfully 25 . In our study, we used local antiseptics, turpentine oil over the umbilicus as a repellent for larva, manually removed the larva and injectable antibiotics were given to avoid sepsis.…”