Influence of body weight, age, and sex on cerebrospinal fluid peak flow velocity in dogs without neurological disorders.

BACKGROUND: Changes in the brain can affect the flow velocity of cerebrospinal fluid (CSF). In humans, the flow velocity of CSF is not only altered by disease but also by age and sex. Such influences are not known in dogs.

HYPOTHESIS: Peak flow velocity of CSF in dogs is associated with body weight, age, and sex.

ANIMALS: Peak flow velocity of CSF was measured in 32 client-owned dogs of different breeds, age, and sex.

METHODS: Peak flow velocity of CSF was determined by phase-contrast magnetic resonance imaging (PC-MRI) at the mesencephalic aqueduct, foramen magnum (FM), and second cervical vertebral body (C2). Dogs were grouped according to body weight, age, and sex. Flow velocity of CSF was compared between groups using linear regression models.

RESULTS: Dogs with body weight >20 kg had higher CSF peak velocity compared with dogs <10 kg within the ventral and dorsal subarachnoid space (SAS) at the FM (P = .02 and P = .01, respectively), as well as in the ventral and dorsal SAS at C2 (P = .005 and P = .005, respectively). Dogs ≤2 years of age had significantly higher CSF peak flow velocity at the ventral SAS of the FM (P = .05). Females had significantly lower CSF peak flow velocity within the ventral SAS of FM (P = .04).

CONCLUSION: Body weight, age, and sex influence CSF peak flow velocity in dogs. These factors need to be considered in dogs when CSF flow is quantitatively assessed.