Response to: An objection to "Congenital external hydrocephalus in a dog".

We appreciate the interest in our article detailing the diagnosis of external hydrocephalus (Gomes I et al i . 2019). Considering the fluid characteristics on MRI, we feel confident that no haemorrhage was evident, although we agree that fluid analysis would have been necessary to definitively confirm this. We consider that a subdural space fluid accumulation would most likely be secondary to a pathological process (inflammation, neoplasia, trauma) particularly in the presence of haemorrhage or haematoma, or following surgical intervention. [Extracted from the article]