ENCEPHALITOZOON CUNICULI
Encephalitozoonosis is caused by Encephalitozoon cuniculi. About 80% of healthy rabbits carry the pathogen, without any clinical signs developing. Clinical disease can present with the following clinical signs: torticollis, ataxia, uveitis, posterior paresis and urinary incontinence. Other clinical signs can occur depending on the particular organs involved (such as hepatic and renal disease).
Transmission is by infectious spores excreted primarily in the urine, transmission can occur both orally and nasally. A pregnant doe can pass the pathogen on to her offspring in utero. The disease is a zoonosis and is an emerging human pathogen.
Detection is now available by two methods both the traditional serology, giving antibody titres, to enable monitoring of clinical cases or detection of active shedding by PCR.
The options available to help diagnose E. cuniculi are:
- Serology – An lgG titre is the most commonly used test, this indicates long term exposure. Levels continue to rise steadily from 30 days post primary infection until they peak at 70 days. An lgM titre is now also available and can be used in conjunction with the lgG. lgM indicates early exposure and new infection in the initial 35 days prior to lgG detection. The sample required is serum.
- PCR – No special medium is required for this test, a sample of urine or CSF simply needs to be placed in to a sterile universal tube. The sensitivity of this test is 99.9%, the specificity 95%. A positive result is conclusive of infection but not necessarily disease.
- RABBIT HAEMORRHAGIC DISEASE – Rabbit Haemorrhagic Disease is caused by a calicivirus, which is highly infectious and virulent affecting rabbits 8 weeks or older, however, rabbits up to the age of 8 weeks can excrete the virus. Morbidity is 70-80% of rabbits in an infected colony within 36 hours of viral entry. Symptoms which may occur are fever, anorexia, depression, cyanosis and haematuria. In the final stages of the disease, rabbits may have epistaxis and develop convulsions. The virus itself is very stable in the environment and may survive for many months. The virus is excreted in almost all secretions and excretions, therefore transmission can be carried out directly through the oral/faecal route, via contaminated feed and other items and biting insects.
A PCR test is now available that will detect both strains of RHD and differentiates between
RHD1 & RHD2 and also detects the new highly virulent strain, but we’re not able to differentiate. The sample required is either fresh Liver, Intestinal Contents or EDTA.
