Caparinia tripilis (Michael, 1889), first reported in Erinaceus europaeus from England , is one of the most important causes of skin disease in hedgehogs . The ears of infested animals become scaly and the skin of the affected parts thickens. The mite causes annoyance to their hosts, which shows pruritic symptoms as they often sit on their haunches and attempt to scratch infested areas with their hind claws. In advanced cases, dry crusts form on the surface of the skin, which thickens, becomes folded, and may even crack. Bleeding can occur when the lesions become worse, spines may fall out, and affected hedgehogs eventually become so incapacitated that they cannot roll up properly . The life cycle of C. tripilis includes egg, larva, protonymph, deutonymph (none of which shows sexual dimorphism) and either an adult male or an adult female . Observations suggest that the complete life cycle encompasses about three weeks . By means of genital suckers, an adult male and a pubescent female (deutonymph) form an attachment pair, which is more or less permanent up until the time of emergence of the adult female from the deutonymphal exuviae. Severe infestation may be found in young animals as early as the age of 4 months and heavily infested animals may die . Infested hedgehogs, therefore, must be isolated and treated.
Treatments in hedgehogs have included organophosphate bath, ivermectin injection, and amitraz spray [4, 5]. After the treatment with organophosphate bath (ParamiteTM, Vet-Kem Co., Dallas, Texas), skin lesions were improved and the condition had not recurred . However, organophosphate insecticide toxicity is the leading cause of major morbidity and death in the insecticide class. The clinical syndrome of organophosphate toxicity varies widely, ranging from the classic cholinergic syndrome to flaccid paralysis and even intractable seizures . While ivermectin (Eqvalan®, Merck & Co., Rahway, New Jersey) administered intramuscularly at 21-day intervals reduced clinical disease caused by Caparinia infestation in A. albiventris, it failed to eliminate the mites. On the other hand, two treatments with a 0.03% rinse of amitraz (Mitaban®, Upjohn Co., Kalamazoo, Michigan) 7 days apart cleared the infestation . An application of 1% permethrin has also been shown to be effective .
Moxidectin, a macrocyclic lactone disaccharide, is a potent, broad-spectrum endectocide with activity against a wide range of nematodes, insects, and mites. First used commercially in Argentina as an injectable formulation for cattle in 1989, it has been widely used as a broad-spectrum antiparasitic remedy for a variety of mammalian species including food-producing and companion animals . It has been reported that moxidectin is 100 times more lipophilic than ivermectin and that the concentration of moxidectin in fat tissue was 90-fold higher than that detected in plasma 28 days following treatment in cattle [9, 10]. The high liphophilic nature of moxidectin may be particularly important as a potent miticide against those parasitic mites that live on the surface of animal skin with sebaceous glands. Recent experimental studies confirmed the efficacy of topical imidacloprid + moxidectin against otoacariosis caused by Otodectes cynotes in dogs  and cats . The imidacloprid + moxidectin formulation were also highly efficacious against the KS1 Ctenocephalides felis, flea strain infesting cats . With the ease of a spot-on medication, the formulation could also be used for parasitic control in exotic pet animals, and studies on ear mite infection caused by O. cynotes in ferrets resulted in successful elimination of the parasite . However, the efficacy and side effects against mange infestation in hedgehogs have not been studied yet. The objective of the present investigation is to evaluate the efficacy and safety of imidacloprid 10% + moxidectin 1% spot-on against naturally infested Caparinia tripilis in hedgehogs.