General information

The pathogen Encephalitozoon cuniculi causes encephalitozoonosis (also called torticollis, wry neck, head tilt) in rabbits. Approximately 80% of healthy rabbits carry the pathogen without showing any clinical signs. Mature infectious spores are mainly excreted in the urine, so that transmission takes place orally and nasally by eating infected food or sniffing at food and litter. However, infected pregnant female hares can also transmit the pathogen to their young in the womb. Faecal shedding of pathogens was detected but seems to be of little importance.

The pathogen has also been found in many other animal species such as dogs, foxes, rodents and some bird species and even in humans. Especially in immunocompromised persons, infection can be relevant.

Apart from head tilt, the clinical picture in rabbits is mainly characterised by ataxia, nystagmus, seizures or cramps. As the disease can also take a milder course, it is recommended to test for E. cuniculi in case of any neurological sign.