Questionnaire-based behaviour analysis of Cavalier King Charles spaniels with neuropathic pain due to Chiari-like malformation and syringomyelia Lynda Rutherford a , Annette Wessmann b , Clare Rusbridge c , Imelda M. McGonnell d , Siobhan Abeyesinghe e , Charlotte Burn e , Holger A. Volk a,⇑ a Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, UK b School of Veterinary Medicine, University of Glasgow, Bearsden, Glasgow, UK c Stone Lion Veterinary Hospital, Goddard Veterinary Group, London, UK d Department of Veterinary Basic Sciences, Royal Veterinary College, London, UK e Centre for Animal Welfare, Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, UK article info Article history: Accepted 20 May 2012 Keywords: Syringomyelia Chiari-like malformation Cavalier King Charles spaniel Pain Quality of life abstract Chiari-like malformation (CM)/syringomyelia (SM) is a disease complex recognised in Cavalier King Charles spaniels (CKCSs) that can lead to neuropathic pain (NeP). In humans, NeP is associated with anx- iety, depression and reduced quality of life (QoL). In this study, databases of three specialist veterinary centres were searched and CKCS breed societies and health forums were contacted to identify CKCS with an imaging diagnosis of CM/SM. Owners completed questionnaires on behaviour, signalment, general health status, NeP and QoL. Data were analysed from 122 dogs out of 564 questionnaires completed, after incomplete questionnaires and data from dogs that had other potentially debilitating disease processes were excluded. NeP severity score was significantly and positively correlated with ‘stranger-directed’ fear (r S = 0.28), non-social fear (r S = 0.34), ‘separation-related’ behaviour (r S = 0.38), attachment behaviour (r S = 0.24), excitability (r S = 0.21) and proxy for pain sensation (r S = 0.29). Increased NeP was also signif- icantly associated with decreased QoL (r S = 0.47), ability to settle (r S = 0.26) and willingness to exercise (r S = 0.50). Severity of NeP was positively associated with certain fear-associated behaviour and with decreased owner-perceived QoL. Thus, neurobehavioural changes should be considered in the manage- ment of NeP in CKCS with CM/SM. Ó 2012 Elsevier Ltd. All rights reserved. Introduction An estimated 95% of Cavalier King Charles spaniels (CKCSs) are affected by Chiari-like malformation (CM) and around 70% develop syringomyelia (SM) (Dewey and Rusbridge, 2008; Parker et al., 2011). In humans, Chiari-type I malformation (the human counter- part to CM) and SM are associated with neuropathic pain (NeP) and present with a variety of symptoms, including headaches, pain in the trigeminal territory, back pain, temporomandibular joint pain and spontaneous pain (Todor et al., 2000; Thimineur et al., 2002). NeP is defined as pain arising as a direct consequence of a lesion or disease process which affects the somatosensory system (Grubb, 2010). The resulting abnormal somatosensory processing can man- ifest as (1) dysaesthesia, a spontaneous or evoked unpleasant abnormal sensation (people with this condition describe burning- type pain, pins and needles and other strange sensations); (2) allo- dynia, pain from a stimulus which is not normally painful, such as light touch or motion; (3) hyperpathia, increased pain from stimuli which are normally painful; or (4) causalgia, a constant, burning- type pain (Gilron et al., 2006; Rusbridge and Jeffery, 2008). CM/SM in CKCS is commonly associated with pain, especially in the cervical region, and with neurological dysfunction, e.g. scolio- sis, limb paresis and ataxia (Rusbridge et al., 2000, 2006). Affected dogs might be hypersensitive to touch and often scratch an area on the shoulder, ear, neck or sternum, commonly only on one side of the body without making skin contact, so called phantom scratch- ing (Rusbridge et al., 2006). Some dogs perform facial or head rub- bing or spontaneous vocalisations. Such clinical signs are thought to indicate the presence of the animal’s perception of NeP, possibly due to damage of the spinal dorsal horn grey matter secondary to SM, as well as overcrowding of the foramen magnum and subse- quent compression of the trigeminal nuclei in the caudal brainstem (Todor et al., 2000; Rusbridge et al., 2006; Rusbridge and Jeffery, 2008). Maximal syrinx width, length and asymmetry strongly predict signs of pain, whilst the degree of cerebellar herniation does not (Lu et al., 2003; Rusbridge et al., 2007; Cerda-Gonzalez et al., 2009). The dorsal horn of the spinal grey matter is central for processing and transmission of sensory information to the brain. 1090-0233/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.tvjl.2012.05.018 ⇑ Corresponding author. Tel.: +44 170 7666365. E-mail address: hvolk@rvc.ac.uk (H.A. Volk). The Veterinary Journal 194 (2012) 294–298 Contents lists available at SciVerse ScienceDirect The Veterinary Journal journal homepage: www.elsevier.com/locate/tvjl