Acta Veterinaria Scandinavica Case study Treatment of rabbit cheyletiellosis with selamectin or ivermectin: a retrospective case study Marianne Mellgren*1 and Kerstin Bergvall2 Address: 1Djurklinik Stigsbo, Stigsbo 213, Stjärnsund, Sweden and 2Department of Small Animal Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, Uppsala, Sweden Email: Marianne Mellgren* - lindstr.mellgr@ebox.tninet.se; Kerstin Bergvall - kerstinbergvall@hotmail.com * Corresponding author BioMed Central Open Access Published: 2 January 2008 Acta Veterinaria Scandinavica 2008, 50:1 doi:10.1186/1751-0147-50-1 This article is available from: http://www.actavetscand.com/content/50/1/1 Received: 23 September 2007 Accepted: 2 January 2008 © 2008 Mellgren and Bergvall; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: A retrospective study of rabbits treated against cheyletiellosis was performed to evaluate the efficacy and safety of selamectin or ivermectin in clinical practice. Methods: Medical records from 53 rabbits with microscopically confirmed Cheyletiella infestation were collected from two small animal clinics. The rabbits were divided into three groups, based on treatment protocols. Group 1 included 11 rabbits treated with ivermectin injections at 200–476 μg kg-1 subcutaneously 2–3 times, with a mean interval of 11 days. In Group 2, 27 rabbits were treated with a combination of subcutaneous ivermectin injections (range 618–2185 μgkg-1) and oral ivermectin (range 616–2732 μgkg-1) administered by the owners, 3–6 times at 10 days interval. The last group (Group 3) included 15 rabbits treated with selamectin spot-on applications of 6.2–20,0 mgkg-1, 1–3 times with an interval of 2–4 weeks. Follow-up time was 4 months–4.5 years. Results: Rabbits in remission were 9/11 (81,8%), 14/27 (51,9%) and 12/15 (80,8%) in groups 1, 2 and 3, respectively. Conclusion: All treatment protocols seemed to be sufficiently effective and safe for practice use. Though very high doses were used in Group 2 (ivermectin injections followed by oral administration), the protocol seemed less efficacious compared to ivermectin injections (Group 1) and selamectin spot on (Group 3), respectively, although not statistically significant. Controlled prospective studies including larger groups are needed to further evaluate efficacy of the treatment protocols. Background Parasite infestation with Cheyletiella species is reported worldwide. The condition is highly contagious, with three species, C. parasitivorax, C. blakei and C. yasguri normally infesting rabbits, cats and dogs respectively [1-3]. Cheyle- tiella mites belong to the order prostigmata and the family Cheyletiellidae. The mites are large (270–540 μm) and very mobile. Adult mites have four pairs of legs with distal combs instead of claws. The mouthpart (palpi) has a pair of curved claws characteristic of the mite Cheyletiella. The three species can be separated morphologically only by the shape of a sensory organ in genu 1 on the first pair of legs. The entire lifecycle of approximately 21 days is spent on the host, where they feed on surface epithelia, debris and lymph. Adult Cheyletiella mites can survive a month Page 1 of 6 (page number not for citation purposes)