Investigation of sensory thresholds in Cavalier King Charles Spaniels with and without Chiari‐like malformations and syringomyelia

Abstract

BackgroundCavalier King Charles Spaniels (CKCS) suffer pain associated with Chiari‐like malformation and syringomyelia (CMSM). People suffer from a similar condition and describe numerous sensory abnormalities. Sensory changes have not been quantified in affected CKCS.ObjectivesTo use quantitative sensory testing (QST) to quantify thermal and mechanical thresholds in CKCS and to compare QST in dogs with and without syringomyelia (SM).AnimalsForty‐four CKCS.MethodsProspective study. Dogs underwent neurological examinations and craniocervical magnetic resonance imaging (MRI). Thermal testing was performed over the humerus and thorax (n = 32); mechanical testing was performed on the paw and neck (n = 44). Latencies, thresholds, and response rates were compared with presence and severity of SM on MRI, presence of pain reported by the owner and pain identified on examination.ResultsThirty dogs had SM, 30 were painful on examination, 29 were owner‐reported symptomatic. Thermal and mechanical variables were not significantly different based on presence or severity of SM. Dogs with pain on examination had decreased mechanical thresholds on the paw (0.38 kg, SD = 0.18) and neck (2.05 kg, SD = 0.74) compared to thresholds of dogs without pain on examination on the paw (0.60 kg, SD = 0.30) and neck (2.72 kg, SD = 0.57; P = .021).Conclusions and Clinical ImportanceMechanical and thermal sensitivity does not appear to be related to the presence of SM, but mechanical sensitivity appears to be related to the presence of pain and clinical signs. Mechanical testing may be useful for assessing sensory abnormalities during clinical trials.

Longitudinal assessment of syringomyelia in Pomeranians

“…Therefore, we elected to include only T1W-based measurements in this study. SM measurements are often recorded absolutely (e.g., a syrinx diameter of 2.2 mm), or dogs are classified in groups with specific measurement categories (e.g., <1.0 mm, 1.0-1.9 mm, et cetera), or dogs are classified as having SM or not based on size (e.g., >2 mm) (6,7,14,19,(22)(23)(24)(25)(26)(27)(28)(29). Few studies provided relative syrinx sizes (e.g., syrinx height: C3 vertebral depth or the spinal cord itself) (9, 13,19).…”

The beneficial role of companion animals in translational pain research

“…Despite this, several conditions in dogs do appear to mimic neuropathic pain conditions in humans. Chiari-like malformation in Cavalier King Charles Spaniels has long been considered to be associated with neuropathic pain and headache ( 109 ), and recently attempts have been made to develop owner-based questionnaires ( 110 , 111 ) and QST ( 112 ) to measure this pain. Intervertebral disk disease pain, nerve root entrapment, nerve root tumors and lick granulomas are all considered to be neuropathic pain conditions, but development of outcome measures has not been comprehensively explored yet.…”

Companion animal models of neurological disease

“…Both of these techniques have been shown to discriminate healthy dogs from those with SCI, and normalization of the sensory threshold parallels locomotor recovery ( Song et al, 2016 ; Gorney et al, 2016 ). The utility of quantitative sensory testing is also being investigated in dogs with spinal cord disorders associated with chronic neuropathic pain pathologies and phenotypes ( Sparks et al, 2018 ).…”