Congenital hydrocephalus in a Maine Coon foetus detected using ultrasound during pregnancy

: A congenital defect that blocks the cerebrospinal fluid outflow is the most common cause of hydrocephalus in young cats. It usually manifests itself within a few weeks of birth. Diagnostic imaging is essential. Therefore, it was decided to report on, for the first time, a clinical case of congenital hydrocephalus in a Maine Coon foetus detected using ultrasound during pregnancy. A difference between the size of the skull bones in the Maine Coon foetuses was recognised during a routine pregnancy ultrasound. Analysis of the sonogram of the bones and brain structures of the diagnosed foetus revealed that the features were highly suggestive of a hydrocephalus. Five clinically healthy kittens and one with hydrocephalus were delivered without complications. The necropsy of the malformed foetus was consistent with the ultrasonographic findings. Bacteriological and virological tests were performed and all were negative which suggest a congenital background of the malformation. This is the first reported case of an intrauterine ultrasound diagnosis of congenital hydrocephalus in a Maine Coon of multiple gestation. The ultrasound control along with the foetometry seem to be useful tools to recognise certain patholo-gies of pregnancy in cats, including congenital malformations of various origins, which is of significant diagnostic and prognostic importance.