Please cite this article in press as: Singh, S.K., Dimri, U., The immuno-pathological conversions of canine demodicosis. Vet. Parasitol. (2014), http://dx.doi.org/10.1016/j.vetpar.2014.03.008 ARTICLE IN PRESS G Model VETPAR-7180; No. of Pages 5 Veterinary Parasitology xxx (2014) xxx–xxx Contents lists available at ScienceDirect Veterinary Parasitology jo u r nal homep age: www.elsevier.com/locate/vetpar Review The immuno-pathological conversions of canine demodicosis Shanker K. Singh a,b,* , Umesh Dimri b a Department of Veterinary Clinical Medicine, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura 281 001, UP, India b Division of Medicine, Indian Veterinary Research Institute, Izatnagar 243 122, UP, India a r t i c l e i n f o Article history: Received 17 January 2014 Received in revised form 26 February 2014 Accepted 1 March 2014 Keywords: Apoptosis Demodicosis IL-10 Immunosuppression Oxidative stress TGF- a b s t r a c t Canine demodicosis is a common but exigent noncontagious parasitic dermatosis caused by overpopulation of the host-specific follicular mites of various Demodex species. Receptivity of dogs to demodicosis and progression of the clinical disease are influenced by numerous factors including; genetic defect, alteration of skin’s structure and biochemistry, immuno- logical disorders, hormonal status, breed, age, nutritional status, oxidative stress, length of hair coat, stage of oestrus cycle, parturition, endoparasitism and debilitating diseases. Of these, the immune status is thought to be the most significant. Thus, in the present review we intended to edify the immuno-pathological conversions of canine demodico- sis. Generalized demodicosis requires a cutaneous environment that is ecologically and immunologically favorable for extreme colonization of demodectic mites. Demodex canis mites can down regulate the CD4+ T cells; possibly by an increased rate of apoptosis or immunological exhaustion of CD4+ T cells. An increased apoptosis of peripheral leukocytes confers progression of the clinical manifestations. Mites induced elevation of TGF- and inhibition of TNF- mRNA expression might be a key factor for revealing the difference in the mechanism of onset between localized and generalized demodicosis. Moreover, an elevated serum level of IL-10 could be accountable for the recurrence as well as occur- rence of demodicosis in dogs. Over production of reactive oxygen species can corroborate immunological discrepancies in dogs with demodicosis. © 2014 Elsevier B.V. All rights reserved. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 2. Immuno-pathological conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 2.1. Immunosuppressive hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 2.2. T-cells misbalance hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 2.3. Immunosuppressive cytokines up-regulation hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 2.4. Oxidative stress and immuno-containment hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 * Corresponding author at: Department of Veterinary Clinical Medicine, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura 281 001, UP, India. Fax: +91 565 2471288. E-mail address: pshankervet@gmail.com (S.K. Singh). http://dx.doi.org/10.1016/j.vetpar.2014.03.008 0304-4017/© 2014 Elsevier B.V. All rights reserved.