Therapeutic effects of oral fluralaner in pet rabbits with severe sarcoptic mange (Sarcoptes scabiei).

Sarcoptic mange is one of the most severe, highly contagious, and fatal ectoparasitic infestations of rabbits. Fluralaner, an isoxazoline class of oral ectoparasiticide, is considered as a very potent acaricide. The present study aimed to evaluate the therapeutic efficacy of oral fluralaner in pet rabbits with severe spontaneous Sarcoptes scabiei infestation. A total of eight un-neutered pet rabbits, tested positive for S. scabiei by microscopy of skin scrapings, were enrolled. Seven rabbits had severe clinical infestation (score 5), while remaining one rabbit had moderate disease clinical signs (score <3). A single oral dose equivalent to 25 mg/kg of fluralaner was administered to each rabbit. On day 14 post-therapy, marked improvements in the skin lesions were observed; severely infested rabbits had a clinical score of 3, while the moderately infested rabbit had a score of 1. However, none of the rabbits tested negative for S. scabiei. On day 30 post-therapy, complete clinical recovery was recorded in all rabbits (Score 0), but, a complete parasitological clearance was not recorded except to the moderately infested rabbit. All rabbits were tested negative for S. scabiei on day 45 post-therapy. Therefore, a single oral dose of fluralaner at a 25 mg/kg was found to be effective in the treatment of severe sarcoptic mange in pet rabbits and no additional topical or systemic medications were needed. Further studies in a larger number of individuals with a bigger spectrum of disease severities (i.e. more moderate/mild) are needed to comprehensively document the safety and efficacy of this drug in mangy rabbits.

Quantification of immuno-regulatory cytokine and toll-like receptors gene expression in dogs with generalized demodicosis.

The proliferation of Demodex mites is mainly controlled by host immunity; however, the precised mechanism of host-mite interplay and host immune response in the cutaneous microenvironment of dogs with generalized demodicosis (GD) are not yet established. In the present study, we envisaged the alterations in the expression of toll-like receptors (TLRs) and immuno-regulatory cytokine gene in the skin lesions and peripheral blood mononuclear cells (PBMCs) of dogs with GD. The expression of TLR2, TLR6, IFN-γ, TGF-ß and IL-10 genes in the skin lesions and PBMCs of 15 dogs with GD was quantified by qRT-PCR. Compared to healthy dogs, significantly elevated expression of TLR2 (P = 0.048), TGF-ß (P = 0.04) and IL-10 (P = 0.012) were found in the PBMCs of dogs with GD. Conversely, there was significantly reduced expression of TLR6 gene (P = 0.021) in the PBMCs of these dogs. The infested dogs also revealed significantly elevated expression of TLR2 gene (P = 0.034) in the skin lesions, while, the expression of the TLR6 gene was found to be significantly (P = 0.004) reduced. Interestingly, significant alterations in TGF-ß (P = 0.105) and IL-10 (P = 0.162) genes expression were not observed in the skin lesions of diseased dogs. Our findings suggest that Demodex mites contribute to a different systemic and cutaneous immune response in dogs for their proliferation, and consequently the development of GD. Therefore, Demodex mites might be inducing the immunosuppression through activating the systemic over-expression of immunosuppressive cytokines; however, in the cutaneous lesions, the expression of immunosuppressive cytokines remained unaltered. Both systemic and local over-expression of TLR2 and reduced expression of TLR6 genes might be responsible for the inflammatory signs of canine demodicosis and helping to the mite to escape the host immunity.