Afoxolaner and fluralaner treatment do not impact on cutaneous Demodex populations of healthy dogs.

BACKGROUND: Fluralaner and afoxolaner are isoxazolines licensed for the treatment of flea and tick infestations. Isoxazolines have also shown efficacy for treatment of demodicosis. Nothing is known about the impact of these compounds on the populations of Demodex in healthy dogs. HYPOTHESIS/OBJECTIVES: The objective of this study was to measure the prevalence of Demodex in the skin of healthy dogs prior to and following the use of either afoxolaner or fluralaner, using real-time PCR (RT-PCR) for Demodex DNA. Our hypothesis was that the use of an isoxazoline at the labelled dose would eliminate Demodex populations from the skin of healthy dogs. ANIMALS AND METHODS: Twenty healthy dogs with no history of skin disease were recruited. Dogs were divided into two groups of ten, with each group receiving afoxolaner or fluralaner for the 90 day study period. Hairs were plucked from three body sites on Day 0 prior to medication administration, then again on days 30 and 90. RT-PCR amplifying Demodex DNA was performed on all samples. RESULTS: At Day 0 (prior to treatment), five of the 20 dogs were positive for Demodex DNA at least in one skin site (25%). At Day 60, three of 18 dogs were positive (16.7%) and on Day 90, six of 20 dogs were positive (30%). No significant difference in numbers of positive dogs was found between groups or timepoints. CONCLUSION: Treatment with afoxolaner or fluralaner does not impact on cutaneous Demodex populations of normal dogs over a 90 day period.

Detection, Prevalence and Phylogenetic Relationships of Demodex spp and further Skin Prostigmata Mites (Acari, Arachnida) in Wild and Domestic Mammals.

This study was conceived to detect skin mites in social mammals through real-time qPCR, and to estimate taxonomic Demodex and further Prostigmata mite relationships in different host species by comparing sequences from two genes: mitochondrial 16S rRNA and nuclear 18S rRNA. We determined the mite prevalence in the hair follicles of marmots (13%) and bats (17%). The high prevalence found in marmots and bats by sampling only one site on the body may indicate that mites are common inhabitants of their skin. Since we found three different mites (Neuchelacheles sp, Myobia sp and Penthaleus sp) in three bat species (Miotis yumanensis, Miotis californicus and Corynorhinus townsendii) and two different mites (both inferred to be members of the Prostigmata order) in one marmot species (Marmota flaviventris), we tentatively concluded that these skin mites 1) cannot be assigned to the same genus based only on a common host, and 2) seem to evolve according to the specific habitat and/or specific hair and sebaceous gland of the mammalian host. Moreover, two M. yumanensis bats harbored identical Neuchelacheles mites, indicating the possibility of interspecific cross-infection within a colony. However, some skin mites species are less restricted by host species than previously thought. Specifically, Demodex canis seems to be more transmissible across species than other skin mites. D. canis have been found mostly in dogs but also in cats and captive bats. In addition, we report the first case of D. canis infestation in a domestic ferret (Mustela putorius). All these mammalian hosts are related to human activities, and D. canis evolution may be a consequence of this relationship. The monophyletic Demodex clade showing closely related dog and human Demodex sequences also supports this likely hypothesis.

Treatment of perianal fistulas with human embryonic stem cell-derived mesenchymal stem cells: a canine model of human fistulizing Crohn's disease.

AIM: To evaluate the safety and efficacy of intralesional injection of human embryonic stem cell (hESC)-derived mesenchymal stem/stromal cells (MSCs) in canine anal furunculosis dogs. MATERIALS & METHODS: Dogs naturally develop an immune-mediated disease called canine anal furunculosis, which shares many features with human fistulizing Crohn's disease. RESULTS: The hESC-MSCs were well tolerated and 1 month postinjection, accompanied by reduced serum levels of IL-2 and IL-6, two inflammatory cytokines associated with Crohn's disease. All six dogs were found to be completely free of fistulas at 3 months postinjection. However, at 6 months, two dogs had some fistula relapse. CONCLUSION: Results of this study provide the first evidence of the safety and therapeutic potential of hESC-MSCs in a large animal model.