Syringomyelia in cavalier King Charles spaniels: the relationship between syrinx dimensions and pain.
OBJECTIVE
This study was designed to test the hypothesis that pain associated with syringomyelia in dogs is dependent upon size and involvement of the dorsal part of the spinal cord.


METHODS
Masked observers determined syrinx dimensions and precise location within the spinal cord on magnetic resonance images of 55 cavalier King Charles spaniels with syringomyelia. After removal of masking, syrinx size and location were compared between the cohorts of dogs that exhibited pain with those that did not.


RESULTS
Maximum syrinx width was the strongest predictor of pain, scratching behaviour and scoliosis in dogs with syringomyelia. Both pain and syrinx size were positively correlated with syrinxes located in the dorsal half of the spinal cord.


CONCLUSIONS
Large syrinxes associated with damage to the dorsal part of the spinal cord are associated with persistent pain suggesting that the pain behaviour expressed by this group of patients is likely to be "neuropathic pain," resulting from disordered neural processing in the damaged dorsal horn. As such it is likely that conventional analgesic medication may be ineffective.
Rusbridge
C
C
Stone Lion Veterinary Centre, 41 High Street, Wimbledon Village, London SW19 5AU, UK.
Carruthers
H
H
Dubé
M-P
MP
Holmes
M
M
Jeffery
N D
ND
D000818:Animals; D015331:Cohort Studies; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D008297:Male; D010146:Pain / Q000209:etiology / Q000662:veterinary*; D010147:Pain Measurement / Q000662:veterinary; D010375:Pedigree; D012720:Severity of Illness Index; D013117:Spinal Cord Compression / Q000150:complications / Q000473:pathology / Q000662:veterinary*; D013595:Syringomyelia / Q000150:complications / Q000473:pathology / Q000662:veterinary*