Encephalitozoon Cuniculi (E.Cuniculi) in Rabbits
What is it?
E.Cuniculi is a parasite that invades cells in rabbits and causes lesions that can affect the brain, kidneys and eye.
How do rabbits get it?
The parasite is obtained by oral ingestion, typically from feed contaminated with infected urine, inhalation or transplacentally (from mum to kit during pregnancy).
Urinary spore shedding occurs about 40 days post infection and stops around 90 days post infection. Spores can remain active in the environment for 4- 6 weeks causing ongoing infection of other rabbits and other species, there is a very small risk to immunocompromised people.
What might I see in my rabbit?
Clinical signs are not always visible, a healthy rabbit can harbor the disease for a long time before the parasite may cause visible changes. Studies have suggested that 52% of healthy rabbits in the UK carry the parasite but many never show any clinical signs
Brain – head tilt, seizures, wobbly walking and hind leg paresis can be suddenly seen. More long term mild changes are head bobbing, stargazing, aggression, balance loss, blindness, not eating caecotrophs (first poos) and urinary incontinence
Kidney – drinking/weeing more, incontinence, kidney failure (loss of appetite and generally unwell)
Eye – low pressure, pain and cataracts if contracted while in the womb, blindness, colour changes in the eye from lens damage and white blood cells
How is it confirmed?
Diagnosing the disease - physical examination, blood testing, radiography and/or CT scanning, urinalysis and serology. These are used to rule out other causes of the symptoms and hope to identify lesions and an immune response to the parasite.
What might be prescribed to help?
Treatment aims to reduce inflammation, block parasite division and help relieve symptoms. Severe disease may be unmanageable and may progress.
An extended wormer course is the main treatment alongside medications to treat the specific signs seen – eye medications, anti-seizure medications and anti-inflammatories
How do I avoid my rabbit getting it?
Regular cleaning and disinfection of the environment can help to minimise the risk of infection from contaminated urine. Quaternary ammonium disinfectants or 1% bleach are effective at disinfecting the environment.
Raised feeding and water stations and the use of hay nets can help prevent feed becoming contaminated with infected urine.
Blood tests on new rabbits can be done, ideally 2 tests 4 weeks apart to catch the early cases, but this may not detect every infected rabbit and only shows they have encountered the parasite, not that they are currently infected.