Encephalitozoan Cuniculi ( E. Cuniculi)

 Encephalitozoon Cuniculi (E .Cuniculi) - An advice sheet for owners

What is E.Cuniculi?

E cuniculi is a spore forming, microscopic parasite that lives inside the cells of their host species. It is a common parasite of rabbits. At present we are unsure exactly what percentage of rabbits have been exposed to E cuniculi but research so far indicates exposure levels to be between 40-60%.

 How can my rabbit catch E.Cuniculi?

It is likely that the majority of rabbits are infected at a very early age from their mother. The route of infection is orally via ingestion of urine contaminated by E. cuniculi spores. One month after infection, a rabbit will start to shed spores in its urine. Shedding of spores continues for up to three months and possibly on and off for life. The spores are tough little things and remain in the environment for more than a month. These spores can then affect other rabbits.

What are the signs of E.Cuniculi?

E.Cuniculi affects the neurological system, the urinary system and the eye

  •  Neurological signs include head tilts, circling, side to side movements of the head or eye, loss of coordination , hind limb weakness and/or urinary incontinence/scalding.

 Urinary system damage can result in excessive thirst, excessive urination, weight loss and/or loss of appetite.

 Deposits of immunocomplexes within the eye can lead to cataract formation.

 How is E.Cuniculi diagnosed?

There are several test which can be carried out to detect E cuniculi. Unfortunately, none is perfect and different tests may suit different situations.

 Blood tests to measure antibody levels (IgG and IgM) can be useful for deciding whether your rabbit has recently been exposed to the disease however there can be false negative results if an antibody response has not developed to measurable levels yet and even if antibody levels are high; it's difficult to know when the exposure occurred.

 Urine PCR tests identify the spores within the urine. A positive result is conclusive for active disease. A negative result is more difficult to interpret. As spores are generally only shed between 38 and 90 days after infection, not every case will be picked up so false negatives are possible. 

What should I do if I think my rabbit might have contracted E.Cuniculi?

Your rabbit should be brought in for testing and to start treatment with a parasiticide for your rabbit and any in contact rabbits. Your rabbit might also need supportive care such as fluids and feeds etc as many rabbits can suffer disability and/or secondary problems as a result of infection.

 How can I protect my rabbit against E.Cuniculi?

As E cuniculi is so widespread, it can be difficult to avoid obtaining a rabbit with E. Cuniculi. You could consider having any potential new bunny blood tested before introducing it to your existing rabbits. Parasiticides can be given to new rabbits for the initial 9 days, particularly as stressed rabbits are more likely to shed the disease.

 Is E.Cuniculi a risk to humans?

E cuniculi can affect humans but is generally only an issue for immuno-suppressed individuals. It has been associated with urinary, cerebrospinal and respiratory tract problems. If you are concerned you should visit your GP for testing. Immuno-suppressed owners may need to consider the options and risks and discuss them with their vet. Testing of your rabbit and careful hygiene are recommended, at the least.