Recent issues of Fur & Feather have discussed this often fatal problem. The symptoms include the rabbit suddenly becoming unstable or wobbly on its legs progressing to paralysis of the hind quarters, or being found lying limp on its side and when being picked up having little or no movement in any of its limbs. Other symptoms can include epileptic type fits, head tilt, rolling around, weight loss and lack of balance. These symptoms occur suddenly in an otherwise healthy rabbit who often dies within days. There appear to be a number of possible different causes such as encephalitizoon cunniculi, severe vitamin deficiency, tumours, intervertebrate disc disease, spondylosis, eating poisonous substances (plants, paints, herbage where a cat or dog has defecated).

One likely cause identified by the West Australian Rabbit Council after a lot of experimentation and medical analysis, and with the aid of Murdoch University, is Vitamin E deficiency. Vitamin E is necessary for the absorption of selenium, a mineral which is part of an enzyme which is involved in the removal of peroxides formed normally in the tissues. The rabbit depends almost entirely on Vitamin E for protection against peroxide damage (and no we are not talking about bleach-blond surfies here). If either Vitamin E or selenium are deficient, the peroxides cause tissue breakdown in the muscles, infertility, re-absorption of foetuses, etc. If the damaged tissue is in the heart, then they suffer heart failure; if in the breathing muscles, then they have respiratory problems or fluid on the lungs; if in the skeletal muscles, they appear stiff and weak and unable to walk.

Factors which affect the amount of Vitamin E a rabbit requires include stress found in overcrowding, poor ventilation, transport, showing and weaning. Poor quality feeds or ingredients containing peroxides create greater demands for Vitamin E. Supplementing the diet with Vitamin E helps in these cases. Processed wheat germ, Endeavour E (a powdered horse additive) or a 'yoghurt sandwich' (bread dampened with milk then spread with yoghurt mixed with Vitamin E) are good sources and useful for pregnant or lactating does every four or five days.

Another possible cause is potassium deficiency which shows as wobbly legs until the paralysis spreads leaving the rabbit flat with only the eyes moving, then death. Potassium injections from the vet work rapidly but 100% pure tomato juice may be syringe fed as much as possible then repeated every hour until the rabbit improves.

Encephalitazoon cunniculi is a parasite which lives in the rabbit's kidneys and urine. This can cause a rabbit to drag its hind legs, followed by death or euthanasia. The parasite migrates to the brain when the rabbit is suffering from stress or dehydration. It causes cysts to develop on the brain which affect whichever part of the body that part of the brain controls. The onset is rapid. The most susceptible are small rabbits and weanlings. The symptoms include white spots in the eye, darting eye, loss of appetite, lack of balance, rolling or lying on its side, epileptic type fits, head tilt, urinary incontinence, hind limb paralysis, weight loss. The source of the parasite is unknown but could be other rabbits, hay, carrots, etc. Treatment needs to be immediate and includes anti-inflammatory steroid injections, Stemetil syrup to relieve head tilt, a course of Baytril antibiotic followed by probiotics indefinitely, Ivomec subcutaneously or in drops once a week for three weeks or a large animal wormer, oxytetracycline, Vitamin E and physiotherapy.

Michael Green of Dr Squiggle pet foods, attributes the problem to digestive tract disorders and describes experiments the company has carried out involving live yeast probiotics to help remove harmful bacteria from the gut, and a blend of herbs which have anti-coccidial, probiotic and immune support functions.