# E. cuniculi in Rabbits UK — Quick answer

PETHEALTH+ (https://pethealth.org.uk/health/rabbit-e-cuniculi-uk): E. cuniculi in Rabbits UK — Quick answer. E. cuniculi is a common UK rabbit parasite affecting brain, kidneys, and eyes. Many rabbits show no signs; others develop head tilt, cataracts, or kidney disease. If your rabbit has neurological signs, phone your rabbit-savvy vet — early fenbendazole treatment and supportive care improve outcomes.

PETHEALTH+ (https://pethealth.org.uk/health/rabbit-e-cuniculi-uk): E. cuniculi in Rabbits UK — What is E. cuniculi?. According to the RWAF, Encephalitozoon cuniculi (E. cuniculi) is a microscopic protozoan parasite that infects rabbits throughout the UK. Studies suggest 30–50% or more of healthy rabbits carry antibodies — meaning they have been exposed. The parasite localises in: - Kidneys — often silently, causing scarring over time - Brain — inflammation causes head tilt and balance loss - Eyes — cataracts and lens inflammation (phacoclastic uveitis) Carrying E. cuniculi is not the same as being ill. Disease flares when the immune system is stressed — by illness, surgery, poor diet, or social stress.

PETHEALTH+ (https://pethealth.org.uk/health/rabbit-e-cuniculi-uk): E. cuniculi in Rabbits UK — How rabbits become infected. According to PDSA and the RWAF, transmission routes include: - In utero — from infected mother to kits (most common) - Urine — spores shed in urine; rabbits ingest from contaminated hay, bedding, or water - Environmental spores — can survive weeks in damp conditions Infected rabbits may shed spores intermittently without appearing unwell. Good hygiene reduces spread in multi-rabbit households but does not eliminate risk entirely.

PETHEALTH+ (https://pethealth.org.uk/health/rabbit-e-cuniculi-uk): E. cuniculi in Rabbits UK — Symptoms of E. cuniculi disease. Not all infected rabbits become sick. When disease develops, signs may include: ### Neurological (most recognised) - Head tilt (torticollis) — see Rabbit head tilt UK - Rolling and inability to stand - Circling to one side - Hind leg weakness or paralysis - Seizures (less common) ### Kidney disease - Increased thirst and urination - Weight loss - Lethargy - Blood tests showing elevated kidney values ### Eye disease - White cataract in one or both eyes — often young rabbits - Eye inflammation and cloudiness - Lens rupture in severe cases Neurological and eye signs may appear suddenly after months or years of silent infection.

PETHEALTH+ (https://pethealth.org.uk/health/rabbit-e-cuniculi-uk): E. cuniculi in Rabbits UK — Diagnosis. According to the BVA, diagnosis is not always straightforward: - Blood antibody tests — show exposure, not necessarily active disease - Clinical signs — head tilt plus history strongly suggest E. cuniculi - Urine PCR — may detect active shedding - Response to treatment — improvement on fenbendazole supports diagnosis - Imaging — CT or MRI in complex cases to rule out other causes Your rabbit-savvy vet interprets tests alongside examination — a negative test does not always rule out disease.

Source: https://pethealth.org.uk/health/rabbit-e-cuniculi-uk