Morsy et al . [ 13 ] found that adult and young rabbits in captivity had a morbidity rate of 76.7 % and 81.5 % when infected with E . cuniculi . The highest mortality rate was recorded in offspring ( 12.3 %), followed by dams ( 5.6 %), and the lowest recorded mortality rate was in males ( 0.04 %). The study did not highlight why males were less likely to die from encephalitozoonosis . However , a similar study also found high mortality rates in young rabbits [ 14 ] .
The morbidity rate in pet rabbits presenting with E . cuniculi infection in veterinary practice is generally unknown , although euthanasia is often considered for those suffering from extreme clinical signs [ 15 ] .
Neurological signs are common clinical presentations of encephalitozoonosis in rabbits , characterised by central vestibular disease ( head tilt , ataxia , circling and rolling , paresis , nystagmus ) ( Figure 2 ) [ 16 ] .
Figure 2 . Rabbit with head tilt [ 16 ] .
In mild cases , the rabbit may cope well with the neurological signs , maintain their balance and be able to eat . For those that are inappetent , assisted feeding may be required to meet their nutritional needs and prevent gut stasis . In severe cases associated with rolling and circling , euthanasia may be indicated [ 15 ] .
Chronic renal failure ( CRF ) has been shown to present in approximately 10 – 30 % of cases , although the clinical signs tend to be less specific . They include weight loss , lethargy and loss of appetite [ 9 , 17 , 18 ] . Urinary incontinence and consequent urinary scalding may present prior to the development of neurological signs . Scalding of the perineum can be due to neurological impairment or due to polyuria associated with CRF [ 12 ] .
VNs can help to reduce the risk of subsequent urinary scalding by clipping and cleaning the area and applying a barrier cream . Clients should be advised to continue to apply barrier creams and to check the perineum area at least once every 24 hours , due to the risk of myiasis .
The ocular manifestation of encephalitozoonosis is relatively uncommon and is characterised by intraocular lesions , cataract formation , anterior uveitis and hypopyon [ 19 , 20 ] . As ophthalmic encephalitozoonosis presents in a variety of ways it is easily mistaken for other ophthalmic conditions , such as uveal neoplasia , therefore a thorough clinical examination and diagnostic procedures are required [ 21 ] .
Diagnosis
Definitive diagnosis of encephalitozoonosis in a live rabbit can be difficult as the parasite is hard to isolate [ 12 ] . Serology of IgG and IgM immunoglobulins can be used in diagnosis , but the severity of clinical signs may not always correlate with the serological titres , due to the parasite ' s life cycle [ 16 ] . The presence of IgG immunoglobulins indicates exposure to E . cuniculi but is not definitive of infection occurring . Repeated serological tests are recommended , as rising titres with clinical signs suggest encephalitozoonosis and treatment is indicated [ 22 ] . Urine testing may also be attempted but can be unreliable due to the intermittent shedding of spores [ 22 ] .
Post-mortem analysis is recommended , especially for multi-pet households and where there are rabbits sharing the same environment . Post-mortem findings include enteritis , pale enlarged kidneys with a pitted appearance , central necrosis in the brain and ophthalmic changes . E . cuniculi can be identified with electron microscopic examination of the brain , retinal cells , kidney and liver [ 13 ] .
Treatment options
Treatment aims to reduce inflammation and prevent the formation of spores . VNs can assist with symptomatic treatment by reviewing actual and potential problems with a nursing care plan . Often these patients experience actual problems with eating , drinking , urination , mobility and the ability to express normal behaviour ( Table 1 , opposite page ). Assessing these actual problems can aid with holistic nursing care and reduce the risk of potential problems occurring . Supportive nursing care often includes fluid therapy , assisted feeding and providing medication under veterinary direction .
The current recommendation for patients with diagnosed infection is a 28-day course of oral fenbendazole at 20 mg / kg every 24 hours , which slows the multiplication of E . cuniculi [ 15 ] . Additionally , the provision of broad-spectrum antibiotics to treat any secondary bacterial infections may be required .
52 Veterinary Nursing Journal