Hydrocephalus is a condition categorised by excessive fluid build-up in fluid-containing cavities of the brain. The name can be broken down to hydro (fluid) and cephalus (brain).
What are the signs of hydrocephalus?
An enlarged head is the most obvious sign of the condition. The top of the skull will appear dome-shaped and the fontanelle (a normal space between the bones of the skull in a neonate/young or foetus) is wider than normal.
What rabbits are affected?
The condition affects neonatal and very young rabbits. Sadly, most affected rabbits are born dead. Very occasionally they can live for several weeks but this is not common. Those rabbits that do survive for days or weeks will often show signs of neurological disease such as nystagmus (flickering of the eyes), ataxia (staggering/wobbly when moving), head tilt and star gazing, with other clinical signs also possible.
What is the prognosis?
Very sadly the prognosis is extremely poor and there is little that can be done. Affected rabbits are best euthanised to stop them suffering. Supportive treatment, in the way of addressing neurological signs, such as padding the environment, supportive feeding and keeping them warm is the only treatment and this is invariably unlikely to make any difference to the eventual outcome.
What is the cause?
Very often cases of hydrocephalus are genetic (passed on by the parents) but can also be the result of dietary deficiency or excessive amounts of vitamin A for the female when and before she was pregnant.
Can it be prevented?
Any rabbits whose offspring are born with the condition should not be used for breeding again as it is likely these rabbits are genetically affected.
How can it be diagnosed?
Diagnosis can be made on clinical signs and also by radiography of the skull. Confirmation can be made by post-mortem exam. Upon post-mortem the brain will be enlarged and filled with cerebrospinal fluid (CSF).