Innovative therapies for Otodectes cynotis infestation in African pygmy hedgehogs: A clinical case report

Abstract

The absence of pharmacologically validated treatment protocols for ectoparasitic infestations in exotic insectivores represents a persistent gap in veterinary therapeutics. This clinical case report describes the application of a multimodal pharmacological approach to treat Otodectes cynotis ear mite infestation in an 18-month-old male African pygmy hedgehog (Atelerix albiventris) presented to the Osaka Institute of Comparative Medicine with bilateral otitis externa, severe auricular pruritus, and progressive weight loss over a six-week period. Otoscopic and microscopic examination confirmed a heavy O. cynotis infestation with a mean baseline density of 45.7 organisms per microscopic field. The innovative treatment strategy combined subcutaneous ivermectin at 0.4 mg/kg on days 0, 14, and 28 with concurrent weekly ceruminolytic ear irrigation and pharmacokinetic monitoring of serum ivermectin concentrations at each clinical visit.Clinical assessments were performed at seven-day intervals over a 42-day period. Mite density declined from 45.7 at baseline to 30.6 (day 7), 17.3 (day 14), 7.8 (day 21), 3.2 (day 28), 0.9 (day 35), and 0.0 (day 42). Integrated heatmap analysis of normalized clinical parameters revealed coordinated improvement across all monitored variables, with parasitological clearance showing the fastest resolution trajectory and erythema the slowest [10]. Phase-based analysis demonstrated that the most effective mite reduction occurred during phase 2 (days 14 to 28), coinciding with peak serum ivermectin concentrations following the second dose. Individual clinical signs reached 50% resolution between days 14 and 26, with crusting resolving earliest and erythema latest. Body weight increased from 279 g to 318 g (14.0% gain), and behavioral activity scores improved from 1.1 to 3.8. No adverse pharmacological reactions were detected. The research confirms that pharmacokinetically guided ivermectin therapy combined with topical ceruminolysis provides effective and safe resolution of O. cynotis in hedgehog patients, and introduces a multimodal monitoring framework integrating parasitological, clinical, and pharmacokinetic data for comprehensive treatment evaluation.