Star Pets.... Fifi!

01 March 2012

This month's star pet is Fifi an adult male giant rabbit (don't be fooled by the name - he had a bit of an identity crisis as a youngster…!)

Fifi was brought into the practice as his owner noticed he had become docile and appeared to be walking oddly and not hopping. On examination by the veterinary surgeon it was noticed that he had lost a lot of weight compared to his previous weigh in and that he appeared to be showing pain on palpating his lower spine. Examination (especially for evidence of dental disease or gut problems) was otherwise unremarkable. It was decide to give Fifi an injection of pain relief and his owner was advised to keep him rested with continued pain relief medication to be given at home. At a check up a few days later Fifi was still quiet and less active than usual and he still appeared to be having problems with his back legs - it was recommended to book him in for further investigation.

Fifi seemed to improve at home for a while but then he was brought back into the practice as he had fallen over, which was unusual. A further examination by our veterinary surgeon revealed that Fifi could not walk very well at all now and had become matted around his back end with urine and faeces. At this point he was booked in for sedation and x-ray of his spine and a blood test for a parasite called Encephalitozoon cuniculi.

Encephalitozoon cuniculi

Encephalitozoon cuniculi (or E. cuniculi) is a parasite carried by rabbits. It can cause partial or complete paralysis, kidney disease, eye disease and death. Recent studies in the UK suggest that 52% of pet rabbits have been exposed to the parasite. Often rabbits do not show any signs of infection until later in life or until illness or stress triggers symptoms to develop.

Transmission between rabbits is either by eating or drinking E. cuniculi spores passed in the urine of infected rabbits or from a mother to her kits before they are born - in this case the parasite can pass into the lens of the eye causing the development of cataracts and sudden ocular inflammation in older rabbits. Spores excreted via the urine can survive in the environment for weeks.

When a rabbit is infected the organism travels via the blood to various organs in the body including the liver, kidneys and brain. The parasite reproduces in the kidney where it can destroy kidney cells. This may results in symptoms including an increased thirst, increased urination, weight loss and at worst death.

When the organism reaches the brain, it forms cysts in the brain tissue. The cysts may rupture resulting in an inflammatory response and affected rabbits show neurological symptoms including: hind limb paralysis, tremors and head tilt. A blood test is used to assist in achieving a diagnosis in rabbits with compatible symptoms - but results needs to be interpreted carefully - 'normal' rabbits may show positive blood results.

Panacur Rabbit

E. cuniculi can be prevented by routine worming of pet rabbits with a nine day course of medication - this is especially important if new rabbits are introduced as stress plays an important factor in progression of the disease. Other preventative measures can be taken such as cleaning/disinfecting hutches, food bowls and water bottles on a regular basis, avoiding contact where possible with wild rabbits, thoroughly washing greens / herbs / grass picked for eating and ensuring every rabbit in a group is routinely wormed.

If blood results reveal evidence of infection with the parasite and a rabbit demonstrates compatible symptoms then a full 28 day course of worming treatment is necessary to treat the disease.

Fifi's treatment

Fifi arrived at the practice the following morning and once he was sedated a blood sample was obtained and sent to an external laboratory to test for evidence of E. cuniculi infection. He also had his spine x-rayed which showed mild arthritis - most likely the source of pain noted on palpation. Before Fifi was woken up we clipped and cleaned the matted fur and sore skin around his bottom. Later that day he was allowed home with further pain relief, antibiotics and Panacur rabbit worming paste to start immediately as infection with E. cuniculi was highly suspected. His owner was also advised to treat her other rabbits at home as a preventative measure.

At a post operative check up a few days later Fifi was responding well to treatment for his sore skin around his bottom and already appeared stronger on his legs. He hated being given his medication though! The improvement with Fifi's hind leg function was good news - it suggested that any neurological damage caused by E. cuniculi was not irreversible.

When his blood test results came back it demonstrated that he had a very high antibody response to E. cuniculi suggesting it was likely that Fifi was either undergoing an active infection or had recently been exposed to the parasite. Given the blood test results, the compatible symptom of hind limb weakness and response to treatment it is likely E. cuniculi was the cause of Fifi's problems.

Hopefully he will continue to do well - he has a few weeks left on his worming treatment and his owner now understands the importance of regular worming of all her rabbits at least twice a year to try to prevent problems associated with this unusual parasite.