Review Diagnosis, genetic control and preventive management of canine hip dysplasia: A review M.M.D. Ginja a, * , A.M. Silvestre b , J.M. Gonzalo-Orden c , A.J.A. Ferreira d a Department of Veterinary Science – CITAB, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal b Department of Animal Science – CECAV, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal c Department of Animal Pathology, Animal Medicine, University of León, 24071 León, Spain d Department of Clinic – CIISA, Faculty of Veterinary Medicine, Technical University of Lisbon, 1300-477, Portugal article info Article history: Accepted 6 April 2009 Keywords: Canine Hip dysplasia Hip laxity Genetic control Preventive management abstract Despite expensive screening and breeding programmes, hip dysplasia (HD) continues to be one of the most common orthopaedic diseases in dogs. The vast majority of dogs afflicted with HD show minimal to no clinical signs, but it can also be a highly debilitating condition for both working and pet dogs. Hip joint laxity is considered a major risk factor for the development of degenerative joint disease and a definitive diagnosis is made if characteristic signs are evident on a ventrodorsal view of the pelvis. Early prediction of the condition can be made using stress radiographic techniques to evaluate the passive hip laxity. The diagnosis of HD may be used for the purpose of selecting breeding stock or to decide on the best treatment approach. Breeding programmes based on individual dog phenotypes have been ineffective and a selection procedure based on breeding value (BV) estimation is recommended. Traditional conser- vative and surgical treatment approaches are reserved for dogs with overt clinical signs of the disease but such treatments can be expensive and aggressive, and are often ineffective in eliminating clinical signs or subluxation and in preventing the development of degenerative joint disease. The implementation of breeding programmes based on BVs and further research into early prediction/diagnosis of HD and effec- tive preventive treatment approaches are essential. Ó 2009 Elsevier Ltd. All rights reserved. Introduction Hip dysplasia (HD) is an inherited, non-congenital disease that is particularly prevalent in large and giant breeds of dog (Mäki et al., 2004; Janutta and Distl, 2006; Ginja et al., 2008b) and the expression of HD genes may be influenced by a number of environ- mental factors (Silvestre et al., 2007). HD is a biomechanical dis- ease characterised by abnormal development of the hip joint and can be a highly debilitating condition for both working and pet dogs (Moore et al., 2001; Vezzoni et al., 2008). However, the vast majority of dogs afflicted with HD show minimal or no clinical signs (Barr et al., 1987; Ginja et al., 2008b). In more severely af- fected dogs, medical and/or surgical treatment is sometimes indi- cated (Farrell et al., 2007; Vezzoni et al., 2008). By convention, a definitive diagnosis is made only if character- istic signs of HD are evident on a standard ventrodorsal radiograph of the pelvis (Corley, 1992; Flückiger, 1995; Gibbs, 1997). Hip joint laxity (HJL) is considered a major risk factor leading to abnor- mal weight-bearing forces and subsequent development of osteoarthritis during or after maturity (Smith et al., 1995; Ginja et al., 2008c). HJL estimated using the distraction index in stress radiographs in dogs at 4 months (Lust et al., 1993; Ginja et al., 2008c) and 2 months of age (Ginja et al., 2009) was correlated or associated with HJL and HD after 1 year of age. Preventive therapeutic recommendations for predisposed pa- tients can be confusing due to the disease’s unpredictable clinical progression and the lack of published scientific data documenting the long-term efficacy of the available treatments (Puerto et al., 1999; Farrell et al., 2007). Therefore, active genetic control based on diagnostic tests of the condition and selective breeding is the best tool to achieve genetic changes decreasing the disease to acceptable levels (Farrell et al., 2007; Ginja et al., 2008b; Janutta et al., 2008). Humans can also be affected by developmental HD, but the therapeutic protocols are well defined and preventive man- agement is always recommended and can even begin immediately after birth (Gerscovich, 1997; Wenger and Bomar, 2003). The purpose of this review is to clarify and discuss, based on the current knowledge, HD diagnostic techniques, control strategy rec- ommendations and preventive management approaches. It is hoped this will bring veterinarians up-to-date and help further educate breeders and owners about the condition. 1090-0233/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.tvjl.2009.04.009 * Corresponding author. Tel.: +351 259350666; fax: +351 259350480. E-mail address: mginja@utad.pt (M.M.D. Ginja). The Veterinary Journal 184 (2010) 269–276 Contents lists available at ScienceDirect The Veterinary Journal journal homepage: www.elsevier.com/locate/tvjl