Floppy Rabbit Syndrome

WHEN "FLOPSY" ISN'T A BROTHER TO MOPSY.
By JENNY BUCKINGHAM.

INTRODUCTION.
The first vision created when the word "flopsy" is mentioned is the popular Beatrix Potter storybook characters Flopsy, Mopsy, Cottontail and Peter Rabbit. However in some rabbit breeding circles the term "flopsy" or "paralysis" refers to an often fatal rabbit condition. This condition is characterised by a progressive paralysis of a rabbit that will lead to death unless treated promptly.

Over the past few years a large number of rabbits have been lost to this condition. Since the condition was first noted, many different theories have been put forward about its cause, effect and treatment. This article traces the different theories, research and treatment that have evolved.

SYMPTOMS.
Unless you are familiar with this condition, often the first sign is an apparently healthy rabbit lying limp in its cage. Upon examination, the rabbit has little or no movement of any limbs and just "flops" in your hands. Sometimes the only sign of life is the small "twitch" of the nose. If you are alert for the condition you can often spot the early signs before the rabbit has progressed to total paralysis. If a rabbit is sitting quietly in the corner of its cage (in no apparent distress) I give it a gentle push. If the rabbit falls over and finds it difficult to regain its feet I immediately suspect Paralysis or Flopsy. Sometimes a rabbit can still be hopping around the cage but its hop seems a little unsteady and unbalanced.

The progression of the condition can vary between rabbits. Sometimes a rabbit can be perfectly healthy and yet an hour later is dead in its cage! Other rabbits can gradually get worse over several hours and remain in a paralysed state for several days. Rabbits with a rapid onset of the condition can rarely be saved.

I have found that most of the rabbits I lose are between four to ten weeks of age - when the doe is weaning them. However other people have found that they seem to lose adult rabbits. A rabbit that has recovered from Flopsy seems to be susceptible at any future time of stress and any offspring appear to be more likely to be affected by it. It also seems as though this condition occurs in certain "lines" of rabbits - often ones with small gene pools.

ALTERNATE DIAGNOSIS.
Breeders that are familiar with this condition can generally diagnose it accurately but there are a few other conditions that have similar symptoms.

Perhaps the most similar with regards to symptoms is hypocalcaemia that is a deficiency of calcium. This occurs most often in pregnant or lactating does. With this condition the rabbit is partially paralysed but tends to kick or twitch when handled. On examination the rabbit may display uncoordinated movements and a tremor on the body or limbs. The tremor or twitching can increase dramatically with handling or sudden noise. These rabbits can often be successfully treated with Calcium Sandos.

Another alternate condition is a broken or injured back. These rabbits usually hold themselves up by the front feet and drag their hindquarters. They may be incontinent and soil themselves. Also their condition does not seem to deteriorate over time.

EARLY THEORIES.
This condition was noticed about four years ago (1992). At first breeders were unsure whether the condition was contagious, caused by a spider bite, due to poisoning or to some type of deficiency. One of the first theories was that the condition was "head-down" disease caused by wooly-pod milkweed poisoning. The symptoms the rabbits displayed were very similar to this disease but access to this weed was difficult to trace. Spider or other insect bites were eliminated as the symptoms were different than previously noted. The condition did not appear to be contagious as only random animals were affected.

The WARCI organised a survey of breeders to try and find out if there were any common factors and the extent of the condition. The condition did not appear to be related to any particular pellets, feeding regimes, water, hutch type or age of rabbits. Some breeders reported that a few affected rabbits appeared to have recovered from the condition. These rabbits had generally been treated with high-energy vitamin supplements such as Nutrapet or Nutragel.

Some sort of diet deficiency seemed to be the most likely theory, possibly linked to certain lines of rabbits being "genetically" vulnerable to this deficiency. Murdoch University became involved and agreed to do tests on rabbits to see if they could discover any common factor. Rabbits that were affected by Flopsy, or died because of it were sent to the Uni for autopsy and tests.

Since rabbits treated with vitamin supplements sometimes recovered, breeders tried to discover which particular vitamin was the culprit. Early laboratory tests seemed to suggest a potassium deficiency and so rabbits were placed on banana diets!! However later tests seemed to discount this theory. Since hypocalcaemia (or low calcium) has similar symptoms many breeders began treating their affected rabbits with Calcium Sandos (an expensive and sticky treatment). This seemed to work sometimes but not always.

A BREAKTHROUGH.
Murdoch Uni found that some rabbits were deficient in Selenium but researchers found it difficult to find accurate base levels for these nutrients. By chance, an American vet visiting Murdoch University’s Veterinary School stated that in America they had found Vitamin E was necessary for the absorption of Selenium. Selenium is a mineral that functions as a part of an enzyme, glutathione peroxidase, that is involved in the removal or detoxification of peroxides, such as hydrogen peroxide, that are formed in tissues during normal metabolic processes. Vitamin E functions by acting as an inter – and intra – cellular antioxidant to prevent peroxide formation; thus Vitamin E and Selenium are very closely related in nutrition. The rabbit is interesting in that it apparently depends completely on Vitamin E for protection against peroxide damage. Both nutrients function by preventing tissue destruction by toxic peroxides formed during metabolism. In a deficiency of either Vitamin E or Selenium, tissue breakdown due to peroxide damage occurs. This results in destruction of muscle tissue (nutritional muscular dystrophy), infertility, reabsorption of foetuses and a variety of other effects..

PERHAPS THIS WAS THE ANSWER.

Armed with this knowledge we began treating our affected rabbits with Vitamin E and found that our success rate for treating these rabbits greatly improved.

AETIOLOGY
Vitamin E is an essential dietary requirement and one of its most important roles is as an inter – and intra – cellular antioxidant to prevent peroxide formation. In this capacity it prevents the oxidation of unsaturated lipid materials within cells. It is also logical to conclude that there is a positive correlation between fat input and vitamin E requirements to prevent peroxidation. The more active the cell – such as those of skeletal and involuntary muscles – the greater the inflow of lipids for energy supply and the greater the risk of damage if Vitamin E is limited. If skeletal muscles are involved, the effect is white muscle disease and the affected animals appear stiff or weak, often unable to rise or walk. If the myocardium (heart muscle) is affected, heart failure which appears as sudden unaccountable death usually results. Involvement of diaphragmatic or intercostals “breathing” muscles may lead to difficulty breathing and an accumulation of fluid in the lungs (secondary pneumonia).

TREATMENT.
When I first heard that a Vitamin E deficiency could be the cause of Flopsy I went to the Pharmacy and bought crushable Vitamin E tablets. Next time I had a rabbit go down with Flopsy (I didn't have to wait long) I mixed up the Vitamin E with some Natural Yoghurt and gave the mixture via a syringe. The recovery was almost miraculous! By next day the rabbit was hopping about his cage ready to go back with his mother. Other breeders tried the same remedy with generally good results.

Since then we have come a long way. I do not save all rabbits but at least I don't feel as helpless as I did before I found an effective treatment. Instead of using crushed Vitamin E tablets I now use Endeavon E a powdered horse vitamin E supplement. I get this from a stockfeeder, it is expensive but it lasts a long time. This Vitamin E powder (and perhaps all Vitamin E tablets?) cannot be mixed with water as it reduces its effect so I mix it with Natural Yoghurt.

As soon as I discover a rabbit with paralysis I give it a dose of Vitamin E. If it readily takes the mixture from the syringe and chews it up and swallows it I know I will probably save that particular rabbit. If the rabbit makes no attempt to swallow the mixture and allows it to dribble out of its mouth, the prognosis is very poor. I then prop the rabbit up in a carry box, using rolled material to hold up the rabbit’s head (in normal alignment) and to stop the rabbit falling over on its side. If it is cold weather I place the rabbit on a hot water bottle. Some rabbits recover very quickly, some take several days to improve. If they are only slowly improving I give the rabbit Nutrapet and water as well via a syringe. Once the rabbit has fully recovered and is returned to its hutch I continue to give them Vitamin E for a few more days.

PREVENTION.
Once we came to realise that our rabbits were dying because of a nutritional deficiency, breeders reviewed their feeding regimes. The recommended nutrient requirement for rabbits (amount per kilo of feed) for Vitamin E is 40mg at times of growth, gestation and lactation. Vitamin E is present in grains but heat processing of these foods destroys the vitamin and so Vitamin E should be added to the rabbits feed. Unprocessed wheat germ is an excellent source of Vitamin E but supply is sometimes limited and storage can be a problem (as weevils love it too). I have successfully used a powered horse additive Endeavon E but this is expensive and you can't be sure if the rabbits are eating it or wasting it.

I have found the best form of prevention is "yoghurt sandwiches". These are made by dampening bread with milk and then spreading the yoghurt mixed with vitamin E over the bread. The rabbits love them and at least I know they are getting the vitamin E. I give these to my pregnant and lactating does (particularly susceptible lines) every four or five days. Once the babies reach five weeks I give the yoghurt sandwich every two to three days until the babies are seven to eight weeks old.

Another factor is your breeding program. Some particular lines of rabbit seem to be affected to a greater extent than others. These lines are usually fairly closely line bred or where there are very few of a particular breed to work with. If I find a particular line or doe is susceptible to this deficiency I try to avoid breeding with them, or if that is not possible I try to outcross to a stronger line. Amazingly I have had litters where most of the babies die of Flopsy over a few days and yet a couple in the litter never show any signs of Flopsy and grow up strong and healthy and breed healthy babies.

Several other factors affect the amount of Vitamin E a rabbit requires or absorbs. Rabbits under stress need more vitamin E than those in less stressful conditions. Overcrowding, poor ventilation, transport, showing and weaning all increase the requirement for vitamin E. If feed selenium supplies are low, additional vitamin E may be required. The greater the content of fat in the rabbits food, the greater the need for Vitamin E. Poor quality feeds or ingredients that contain peroxidising fats increase the requirements for vitamin E. Grain stored in moist conditions or stored for a long period of time loses its natural vitamin E. Losses during pelleting are usually around 10 – 20%. However they can be as much as 50% if water is added to the mix (humidification).

CONCLUSION.
If you don't have a problem with paralysis there is probably no need to change what you are doing, but if you occasionally lose rabbits for no apparent reason, Flopsy due to Vitamin E deficiency is probably worth considering. If you do think that this may be affecting your rabbits then prevention is certainly better than cure. The key to saving your rabbits is careful observation, proper diagnosis and prompt treatment. If you find that you are losing a number of rabbits from this condition you need to look at your feeding regime and breeding practices.

Further Reading
Selenium for Animals


This Document is Copyright © Jenny Buckingham. 1996. UK. ALL RIGHTS RESERVED.