Chiari‐Like Malformation and Syringomyelia in American Brussels Griffon Dogs

Abstract

BackgroundAlthough Chiari‐like malformation (CM) and syringomyelia (SM) have been described in many small breed dogs, the prevalence and clinical manifestations of this complex have not been documented in a large cohort of American Brussels Griffon (ABG) dogs.ObjectivesTo characterize the clinical and magnetic resonance imaging (MRI) features of CM and SM in the ABG breed.AnimalsEighty‐four American Kennel Club registered ABG dogs were recruited.MethodsProspective study. Complete histories and neurologic examinations were obtained before MRI. Images were blindly reviewed and calculations were made by using OsiriX. All analyses were performed by Student's t‐test, Spearman's correlation, ANOVA, and chi‐square test where appropriate.ResultsChiari‐like malformation and SM were present in 65% and 52% of dogs, respectively. Twenty‐eight percent of dogs had neurologic deficits and 20% had neck pain. Mean central canal (CC) transverse height was 2.5 mm with a mean length of 3.6 cervical vertebrae. Neurologic deficits were significantly associated with a larger syrinx (P = .04, P = .08) and syrinx size increased with age (P = .027). SM was associated with a smaller craniocervical junction (CCJ) height (P = .04) and larger ventricles (P = .0001; P < .001).Conclusions and Clinical ImportanceSyringomyelia and CM are prevalent in American Brussels Griffon dogs. Syrinx size is associated with neurologic deficits, CM, larger ventricles, a smaller craniocervical junction height, neurologic deficits, and cerebellar herniation. Fifty‐two percent of dogs with a SM were clinically normal.

Syringomyelia and Craniocervical Junction Abnormalities in Chihuahuas

“…All dogs in our study had CM. This finding is similar to previous studies, with occurrence of CM in nonrandomized CKCS study populations varying between 94 and 100%, but higher than the 60.7–80% reported in Griffon Bruxellois dogs …”

“…Chiari‐like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels (CKCSs) and Griffon Bruxellois dogs . Increasing evidence indicates that CM and SM also occur in other small and toy breed dogs (e.g, Yorkshire terriers, Chihuahuas, Maltese dogs, Pugs, Miniature poodles, and Pomeranians) …”

Syringomyelia in a Newborn Male Simmental Calf

“…However, no evidence of SBV, BVDV, and BTV were found in the calf, dam, or herd, and no vaccinations against these viruses had been administered on the farm in question. Syringomyelia as described in the literature is often combined with additional disorders such as Dandy‐Walker syndrome, scoliosis, cleft palate,22 Arnold‐Chiari like malformation,7 dicephalus or spinal dysraphism 23. It is an abnormal spinal cord development,1 that includes – among others ‐ hydromyelia, aplasia, or hypoplasia of the spinal cord, diplomyelia, aberrations of the central canal and of dorsal or ventral septa.…”

“…In chronic cases, the cavities can be lined with reactive astrogliosis. Syringomyelia has been most intensively studied in Cavalier King Charles Spaniels but occurs in other mammals 2, 3, 4, 5, 6, 7. It was previously considered a rare condition in small animal medicine, but because of higher prevalences in certain dog breeds and the increased availability of magnetic resonance imaging (MRI), it has become a relatively common neurological diagnosis 8…”

Low‐Field Magnetic Resonance Imaging and Multislice Computed Tomography for the Detection of Cervical Syringomyelia in Dogs

“…A syrinx of >6.4‐mm wide causes clinical signs in 95% of CKCS 12. In a study conducted in American Brussels Griffon dogs, there was no association found between the size and pain, only between size (>1 and <2 mm) and Chiari malformation signs 35. Also in human medicine signs of pain are not well correlated with the size of the syrinx.…”