Comparative Study by Computed Radiography, Histology, and Scanning Electron Microscopy of the Articular Cartilage of Normal Goats and in Chronic Infection With Caprine Arthritis-Encephalitis Virus VIDELINA RODRIGUES DE SOUSA, 1 FRANCISCO DAS CHAGAS ARA  UJO SOUSA, 2 OSMAR FERREIRA DA SILVA FILHO, 1 ROSE ELI GRASSI RICI, 3 ANAEMILIA DAS NEVES DINIZ, 1 LA  ECIO DA SILVA MOURA, 4 JACYARA DE JESUS ROSA PEREIRA ALVES, 5 ANT ^ ONIO DE SOUSA J  UNIOR, 1 MARIA ANG  ELICA MIGLINO, 3 JO ~ AO MACEDO DE SOUSA, 6 FELIPE DE JESUS MORAES JUNIOR, 1 AND FL  AVIO RIBEIRO ALVES 7 * 1 Animal Science Post-Graduate Program, Federal University of Piau  ı (UFPI), Teresina, Piau  ı, Brazil 2 Faculty of Medical Science, State University of Piau  ı (UESPI), Teresina, Piau  ı, Brazil 3 School of Veterinary Medicine and Animal Science, University of S~ ao Paulo (USP), S~ ao Paulo, S~ ao Paulo, Brazil 4 Scientific Initiation Program (CNPq), School of Veterinary Medicine, Federal University of Piau  ı (UFPI), Bom Jesus, Piau  ı, Brazil 5 Surgery Post-Graduate Program, Federal University of Cear a (UFC), Fortaleza, Cear a, Brazil 6 Department of Veterinary Medicine and surgery, Federal University of Piau  ı (UFPI), Teresina, Piau  ı, Brazil 7 Department of Veterinary Morphophysiology, Federal University of Piau  ı (UFPI), Teresina, Piau  ı, Brazil KEY WORDS Arthritis; inflammatory joint disease; lentivirus; caprine; DJD ABSTRACT In the northeast of Brazil, caprine arthritis-encephalitis (CAE) is one of the key reasons for herd productivity decreasing that result in considerable economic losses. A compara- tive study was carried out using computed radiography (CR), histological analysis (HA), and scanning electronic microscopy (SEM) of the joints of CAE infected and normal goats. Humerus head surface of positive animals presented reduced joint space, increased bone density, and signs of degenerative joint disease (DJD). The carpal joint presented no morphological alterations in CR in any of the animals studied. Tarsus joint was the most affected, characterized by severe DJD, absence of joint space, increased periarticular soft tissue density, edema, and bone sclero- sis. Histological analysis showed chronic tissue lesions, complete loss of the surface zone, absence of proteoglycans in the transition and radial zones and destruction of the cartilage sur- face in the CAE positive animals. Analysis by SEM showed ulcerated lesions with irregular and folded patterns on the joint surface that distinguished the limits between areas of normal and affected cartilage. The morphological study of the joints of normal and CAE positive goats deep- ened understanding of the alteration in the tissue bioarchitecture of the most affected joints. The SEM finding sustained previous histological reports, similar to those found for rheumatoid arthritis, suggesting that the goat infected with CAE can be considered as a potential model for research in this area. Microsc. Res. Tech. 77:11–16, 2014. V C 2013 Wiley Periodicals, Inc. INTRODUCTION Goat breeding in the Northeast of Brazil is severely affected by high indices of health problems. Goat herd in Brazil has been estimated at 9,313 million heads, and the Northeastern region has 90.0% of the total number (Gregory et al., 2009), but improper manage- ment practices interfere greatly in herd productivity (Mart  ınez-Naval on et al., 2013). One of the main factors in productivity decreasing is caprine arthritis-encephalitis (CAE) caused by an RNA virus of the lentivirus genus, Retroviridae family (Lima et al., 2004), isolated for the first time in the United States in 1980 by Crawford and Narayan. In Brazil, CAE was first observed in Rio Grande do Sul state (Moojen et al., 1986). In the Northeast, it was first reported in Cear a, due to changes in the milk pro- duction systems, such as the importation of males of exotic goat breeds to improve the genetics of the native herds (Callado et al., 2001; Pinheiro et al., 1989). CAE has accounted for incalculable economic losses, including young animal death, decreased milk produc- tion, and weight loss in adults, because of moving diffi- culty. Consequently, there has been herd devaluation, early animal replacement, and expenses with control measures and commercial barriers against products (dams, reproducers, and semen) (Alvarez et al., 2005; Gjerset et al., 2009). Clinically, the disease is characterized by progres- sive weight loss, skin flaking, rough fur, markedly *Correspondence to: Fl avio Ribeiro Alves, Department of Veterinary Morpho- physiology, Federal University of Piau ı, Teresina, Piau ı, Brazil. E-mail: flavioribeiro@ufpi.edu.br Received 10 August 2013; accepted in revised form 21 October 2013 Review Editor: Prof. George Perry Contract grant sponsor: National Council for Scientific and Technological Development (CNPq). DOI 10.1002/jemt.22306 Published online 4 November 2013 in Wiley Online Library (wileyonlinelibrary.com). V V C 2013 WILEY PERIODICALS, INC. MICROSCOPY RESEARCH AND TECHNIQUE 77:11–16 (2014)