SMALL MAMMAL HEALTH SERIES By Susan Brown, DVM

There are many diseases that can affect the neurological state of a rabbit. It is often necessary to perform one or more diagnostic tests to determine the cause. We will look at a list of some of the more common diseases that can result in paralysis or weakness of the pet rabbit.

SPONDYLOSIS OF THE LUMBAR SPINE

Cause - This is a fairly common disease of rabbits over 4 years of age, particularly females of medium to large breeds. The vertebrae in the lumbar (lower back) area gradually develop small bony protrusions (spurs) that can eventually bridge to the adjacent vertebrae resulting in the fusion of the two together. The exact reason this happens is unknown, but it is likely an aging process. It can be aggravated if a rabbit is carrying excess body weight or perhaps does not get adequate exercise during its life. This is not life threatening and can progress slowly for years.

Signs - The fusing of the vertebrae decreases the flexibility of the spine and prevents the rabbit from being able to jump and run as easily. Before these bony spurs fuse completely, they can rub against each other and cause pain. The pain can come and go dependent on things such as the weather and how much exercise the rabbit got the day before. Rabbits severely affected with this disease "shuffle" rather than hop and on some days can become very reluctant to move at all. The rabbit may also have difficulty getting in and out of the litter box. Grooming can become a problem when the spine is painful or inflexible and there may be evidence of urine or stool collection around the hindquarters. In addition, rabbits with this condition may not be able to scratch their ears and therefore an excess amount of earwax may accumulate.

Diagnosis - The diagnosis is based on finding the bony changes on a x-ray of the spine.

Treatment- Since we do now know why this disease occurs we cannot advise on prevention, however maintaining a normal weight and allowing plenty of exercise throughout the pet's life surely is beneficial. The disease is managed once it is diagnosed primarily with pain medications. Pain medications used can include aspirin, nonsteroidal anti-inflammatory drugs, and corticosteroids. All these medications should be used with caution and only under veterinary supervision. Acupuncture and chiropractic treatments have also provided relief for many patients and reduced the need for or amount of pain medications used. It can be helpful to regularly massage or apply heat to the back. Gentle massage over the muscled areas of the back only, never directly over the bone, can warm the area and help decrease muscle tightness. In addition, if the rabbit is overweight then reduce the workload on the back by reducing the weight. As the disease progresses, it will be necessary to keep the hind quarters clean from urine and stool and to provide soft, absorbent bedding to prevent "bed sores" and pododermatitis (foot pad infections). Check the ear canals at least once weekly for excess wax accumulation.

INTERVERTEBRAL DISC DISEASE (IVD)

Cause – This disease can occur in many species of pets as well as humans. Intervertebral discs are the “padding” located between each vertebrae of the spine. This pad is made up of a tough fibrous capsule enclosing a thick jelly-like substance. The intervetebral disk acts to absorb shock when the animal is moving and prevent the movement of bone against bone. Occasionally the capsule can tear or bulge and cause put pressure on the spinal cord that runs through the upper part of the vertebrae. Pressure on the spinal cord can cause affect the function of nerves starting at the area of the pressure and moving all the way back to the tail. Most often IVD occurs in the back, but can also occur in the neck and over the check area. It can occur as the result of trauma or for other unknown reasons.

Signs – Signs of IVD depend on what part of the spine is affected and how much pressure is being applied. There may be a mild weakness to a complete paralysis.

Diagnosis – The diagnosis of IVD can sometimes be made on a plain x-ray. However, often it is necessary to inject a radio-opaque dye into the spinal fluid and then x-ray the rabbit again, looking for changing in the anatomy of the spinal cord. This procedure is called a myelogram.

Treatment – The treatment of IVD depends on the extent of disease, but will usually include cage rest and the use of anti-inflammatory drugs, particularly corticosteroids. In some cases it may be necessary to perform surgery to release the pressure on the spine.

TRAUMA

Cause: Damage to a rabbit's back by any kind of trauma can lead to partial or complete paralysis of the hind limbs. The most common cause of back trauma occurs during restraint of a rabbit when it kicks out suddenly or twists. Even when the best restraint is used, it is still possible for this situation to occur. The force of the kicking or twisting can literally fracture vertebrae in the back. The fractured vertebrae are then unstable resulting in severe bruising or severing of the spinal cord. Rabbits can also sustain this kind of trauma (although rarely) when running or playing. Rabbits that are confined to cages and not allowed daily periods of exercise are at an increased risk for this disease due to decreased bone density.

Signs: Complete or partial paralysis is immediately evident after the injury. There may be a loss of bladder and bowel control.

Diagnosis: The damaged vertebrae can usually be seen on a x-ray. Occasionally the vertebrae will "snap" out of place during the injury, cause damage to the spinal cord and then go back into place by the time the x-ray is taken. These cases can be difficult to diagnose unless high detail x-ray film is used or a myelogram is performed.

Treatment - If the spinal cord is completely severed or seriously bruised, there is no treatment that will return normal neurological function. Euthanasia should be considered for these patients because their quality of life will be very poor. Cases that have only mild to moderate damage to the spinal cord or that still have sensations in the toes and maintain bladder or bowel control have a chance of healing. These rabbits should confined to a cage for a period of 6 to 8 weeks to facilitate healing of the fractured bones. Corticosteroids may be used for the first few days after the injury. Many of these rabbits will regain at least partial if not total neurological function and live a fairly normal life.

PARASITES

The two most common parasites causing neurological disease in the rabbit in the United States are Encephalitozoon cuniculi (also known as Nosema cuniculi) and Baylisascaris procyonis.

Encephalitozoon cuniculi

Cause - Encephalitozoon cuniculi is a protozoon from the microsporidia family that can infect a number of species of animals, including humans. In humans infections are rare except in immunocompromised individuals such as AIDS patients or those suffering from tropical diseases. Some species, such as dogs and cats, either die from the disease or survive the infection and completely clear it from their bodies. In rabbits and mice however, the infection is persistent throughout their lives and may or may not cause obvious signs of disease. Even within species it appears that some genetic strains are more resistant to infection than others.

E. cuniculi is passed from infected animals through the urine. The oral route is the most common method of transmission. The spores also can be inhaled and enter the body through the lungs. There is still controversy over whether or not the disease is transmitted through the placenta in the unborn young. The rate of infection in kits is highest when the mother is positive for this disease. Whether this is because the spores are in the environment from previous shedding by the mother or because there is transmission through the milk or placenta has not been definitively determined. Once the spores are in the body, they become “active” and spread throughout various tissues including kidneys, liver, lung, spinal cord and brain. Microsporidia that infect the kidney go on to actively produce more spores that are then passed in the urine in large numbers within 30 days. The spores are produced for up to 90 days post infection, at which time they stop and the rabbit can no longer infect others. E. cuniculi infections are very common in pet rabbits in the United States. Up to 80% of clinically normal rabbits tested in some populations were positive for this disease. It can not only be transmitted from other affected pet rabbits, but also from wild rabbits and rodents.

Signs - Fortunately most rabbits affected with this parasite remain completely normal throughout their lives. However, some rabbits develop mild to serious disease. It is unknown why some rabbits develop clinical disease and others do not, although as mentioned previously it might depend partially on genetics. Certainly animals that are immunocompromised are at a higher risk.

The clinical signs in rabbits usually involve disease of the kidney, brain or spinal cord. If severe kidney disease is present, a generalized weakness may be observed which could be initially mistaken for a neurological problem. In addition to weakness and depression, the rabbit may exhibit a poor appetite, increased water intake, and increased urination, an ammonia odor to the breath and sudden death.

If the brain or spinal cord is infected, the signs may vary depending on what area is damaged. A rabbit may experience any one or combination of the following: unilateral or bilateral facial paralysis, weakness in only one limb, complete hind limb weakness or paralysis, all four limb weakness or paralysis, head tilt, loss of appetite, behavior changes, depression, seizures (mild to severe) and sudden death.

Diagnosis – The blood test currently available to detect the presence of E. cuniculi in the rabbit measures antibodies to the parasite. The test was primarily designed to detect positive animals in a breeding colony or laboratory setting so they could be removed from the population. The test is of limited use in pet rabbits because it does not prove that this parasite is the cause of the clinical signs present. In other words, many rabbits have been exposed to this parasite and are infected, but will never show any signs of disease. Therefore, if we get a positive test, it only means that the rabbit has the parasite in its body, it does not prove that the parasite is responsible for any of the clinical signs we are currently seeing. The only way to diagnose if the parasite is actually causing the signs would be to take a biopsy the affected tissue. In the case of kidney disease, this is possible, but taking a biopsy of the brain or spinal cord is not practical and can be very dangerous. Therefore, we can only make a tentative diagnosis of E. cuniculi based on the rule out of other diseases along with the presence of a positive E. cuniculi test showing that the animal has the potential for having a problem with this parasite.

Treatment - Unfortunately there is no clinically recognized treatment for an active infection of E. cuniculi. Drugs such as ivermectin and other parasiticides have been tried without success. The parasite lives within the cells and it is very difficult to get medication into this protected area. For the past several years oxybendazole, which is an antiparasitic drug, has been used in rabbits with suspected E. cuniculi disease. Some cases seem to show improvement, but it is impossible at this time to prove that the improvement was the result of the drug or because of other factors, including the fact some rabbits show improvement without medication. In addition, it is not possible to reverse the effects of brain, spinal cord or kidney damage once it has occurred therefore any drug used for treatment of this disease can only act to prevent further spread can not cause a complete “cure”. Rabbits that have clinical signs of disease should be supported with good nursing care. Antibiotics, analgesics and anti-inflammatory drugs may be used as needed for secondary problems that may develop.

Most pet rabbits have probably contracted the infection from the mother. Rabbits that are obtained as adults and that are not used for breeding are not likely to shed the spores. However, young rabbits under 4 months of age that may have contracted the disease from the mother could be actively shedding the spores in their urine. It would probably be a good idea to isolate rabbits less than 5 months of age from other rabbits in the house. An E.cuniculi test could be run on these youngsters to determine if they are carrying the parasite. If they are negative, they could be put with the other rabbits earlier than 5 months of age. We have been unable to find a definitive source that indicates the best product with which to clean the environment and remove any spores. Any materials that are contaminated with urine, such as wood or carpet, that cannot be cleaned thoroughly should be destroyed. Other substances, such as plastic and metal should be scrubbed with a phenol disinfectant (Lysol is one example) or a strong bleach solution and then rinsed thoroughly.

Baylisascaris procyonis

Cause - Baylisascaris procyonis is the scientific name for an intestinal roundworm found in raccoons in North America, Japan and Germany. It is estimated that some populations of raccoons have a 68 to 82% infection rate with this parasite. Skunks carry a similar species, Baylisascaris columnaris that can also affect other species of animals. All the things said about the raccoon roundworm will also apply to the skunk roundworm.

B. procyonis does not adversely affect the raccoons that carry it. The eggs of the parasite are passed by the millions in raccoon feces where they can stay in the environment for years withstanding both heat and cold. When a species of animal other than a raccoon swallows an egg the microscopic larva hatches out in the intestine and then burrows through the wall of the intestine and begins migrating through the body trying to find a home. The body in turn tries to kill the larva and it moves rapidly to escape attack. The larvae seem to have a preference for lodging in the liver, eyes, spinal cord or brain. Occasionally they can be found in other organs. When a larva tries to make a home it causes a great deal of damage as the body tries to either kill it or wall it off from other tissues. Eventually the larva dies and is reabsorbed by the body. In very small species such as mice only one or two larvae in the brain can be fatal. If the larva does not cause significant damage in vital organs then the victim will show no signs of disease. Species other than the raccoon that are affected with this parasite CANNOT pass it on to anyone else. This is the end of the line for the larva and it never becomes a mature adult capable of producing eggs.

There are over 50 species of animals that are affected by this parasite including dogs, squirrels, chinchillas, guinea pigs, mice, rats, birds and humans. This parasite is responsible for disease or death in humans, usually children, every year in this country.

Signs - The signs of disease caused by B. procyonis are similar in all species affected and depend on the amount of damage and the organ(s) affected. Signs can include any combination of the following: sudden lethargy, loss of balance, abdominal pain, paralysis of one or both sides of the body, loss of muscle coordination, head tilt, blindness, coma and death. In humans the signs appear approximately 2 to 4 weeks after exposure.

Diagnosis - In humans there are more options open for diagnosis of this disease. There is a blood test to find out if the person has antibodies to the parasite. This is currently not readily available for rabbits. In humans there is a change in the blood count resulting in a high level of white blood cells called eosinophils. These blood cell also occurs in high numbers in the cerebrospinal fluid (the fluid around the brain and spinal cord). Unfortunately rabbits do not respond consistently in the same way. Finally humans can more easily have dye studies done of the brain or other tissues through the use of CAT scans or MRI's, something that can be cost prohibitive or simply not available for the pet rabbit.

Diagnosis in the rabbit is most often based on the rule-out of other diseases such as infectious, toxic, traumatic or E. cuniculi and the possibility of exposure to material contaminated by raccoon feces. Unfortunately the diagnosis is often not made until after death when the brain and other organs can be examined microscopically for the presence of B. procyonis larvae.

Treatment - Currently there is no effective treatment for this disease. The problem is that there is a great deal of damage already present by the time the rabbit shows signs of illness. Most antiparasitic drugs cannot penetrate the tissue in high enough doses once the parasite is walled off. Some sources suggest that using an antiparasitic drug anyway might slow down or kill the larvae that are still migrating, but this has not been proven. The current suggestion is to use high levels of corticosteroids immediately upon observation of signs to try to suppress the inflammation that is taking place in the affected tissues. In humans this seems to help alleviate some of the signs as least temporarily. Corticoteroids are not a cure nor will they reverse all the damage, but they may minimize the trauma to the tissue. Corticosteroids have to used with caution in rabbits because they may worsen any bacterial disease present and they may cause alterations in the flora of the cecum. An injection of a short-acting corticosteroid might be helpful initially and then continued based on the rabbit's clinical response.

Prevention - This is really the best option for controlling this disease. Since this disease is just as dangerous to humans and other pets as it is to rabbits then these precautions are doubly important. Here are some recommendations from Kevin Kazacos, DVM, PhD at Purdue University in W. Lafayette, Indiana. Dr. Kazacos is currently studying this parasite in pets and wild animals and has written a number of excellent articles on this disease.

• Do not keep raccoons as pets. Not only are they not suitable for pets because they are wild animals, but they may pose a serious health risk.
   
• Learn to recognize raccoon latrine areas and either stay away from them or clean them up if necessary. Favorite spots are at the base of trees, in the forks of trees, on fallen logs, large rocks, woodpiles, decks, in attics, garages, chimneys, barns and outbuildings. In addition raccoons like to nest in haylofts and may contaminate hay or straw that is used for bedding or food. Purchase hay or straw from a clean source and dispose of any bales that show evidence of fecal contamination. Do not store the hay you buy in areas that raccoons have access to. Be cautious using and handling fallen timber for firewood.
   
• Monitor children closely in potentially contaminated areas. Children are the most easily affected because they frequently put unwashed hands in their mouths. Do not house rabbits on the ground in areas inhabited by raccoons.

It may be possible to have soil samples tested in your yard to see if the area is contaminated. Cleaning up a latrine area can be a challenge. The eggs of the Baylisascaris species are extremely resistant to environmental conditions. The eggs can survive for YEARS. They are resistant to all common disinfectants including bleach. The best way to kill the eggs is through flaming the area (including soil) or burning affected material such as straw or wood cages. Alternately, boiling water can be poured over small areas at a time. In heavily contaminated areas it may be necessary to remove and bury the soil in a deep spot elsewhere. When cleaning up any latrine area, proper protection is a must which should include a dusk mask over the nose and mouth, disposable clothing, disposable gloves and heavy rubber boots that can be cleaned with boiling water.

Prevent further contamination of the area by blocking off access routes for raccoons, not feeding raccoons around the property and using repellents such as mothballs around potential access areas.

TOXINS

Cause – Rabbits that are allowed free unsupervised access to their surroundings can come in contact with a wide variety of toxic substances. Toxic materials can include some plants, rodenticides, insecticides, human medications, antifreeze and heavy metals. Heavy metal such as lead, zinc can be found in old housepaint, old metal cages, jewelry and old stained glass products to name a few.

Signs – The signs are variable depending on the toxin and how much was ingested. Rabbits do not have the ability to vomit so once they take in a toxic substance they are unable to remove it from their body quickly. Signs seen may include any one or combination of the following; lethargy, rapid breathing, loss of appetite, weakness, paralysis and collapse.

Diagnosis – The diagnosis of toxicosis depends on a number of factors including the history of exposure, blood tests to determine abnormalities and x-rays to detect the presence of metallic substances in the gastrointestinal tract. Any information you can give regarding the rabbit's environment and history of the signs is probably the most important factor in determining the cause of the disease.

Treatment – The treatment is based on the toxin ingested. The effects of many toxins can be reversed if caught in time.

CEREBROVASCULAR ACCIDENT (CVA or “STROKE”)

Cause: CVAs are not as common in our pets as they are in humans. A CVA is a caused by either an obstruction of the flow of blood through a blood vessel in the brain or when a blood vessel ruptures and bleeds out into the surrounding brain tissue. Both “vascular accidents” can cause mild to severe brain tissue death. Rarely, an animal can have a stroke following a surgical procedure due to a blot clot becoming lodged in a blood vessel in the brain.

Signs - The signs depend on where the damage took place in the brain and may range from mild facial or extremity muscle weakness to complete paralysis of one or both sides of the body. Sudden death can also occur. The incidence of CVAs increases both in animals and people with age.

Diagnosis - It is very difficult to diagnose a CVA in an animal without the sophisticated equipment available to humans. In humans, a diagnosis of CVA is made with one or more of the following procedures; arteriography (a radiographic dye study of the brain's blood vessels), CT (computed tomography) scan or MRI (magnetic resonance imaging). In animals a diagnosis of stroke is usually suggested based on ruling out other causes of disease. In some areas CT and MRI diagnostics are available and can be used on your pet as well.

Treatment - There is no specific treatment for a CVA. The only thing that can be done is to support the pet with fluids, assist feedings and pain medications if necessary. Blood thinning medications are used as well in humans and may be used in your pet the CVA was caused by a blood clot. If the rabbit has lost the ability to control its bathroom habits, then it will have to have its bladder expressed several times a day and kept clean and dry. It can take weeks to months for the nerve tissue to heal and usually there is some degree of irreversible brain damage. You should discuss your bunny's prognosis with your veterinarian and decide what the best and most humane course of action should be for your pet.

BACTERIAL INFECTIONS

Cause - There are many types of bacteria that can cause infections in rabbits. Bacteria can enter the cerebrospinal fluid (fluid surrounding the brain and spinal cord) or small abscesses can form in the brain or spinal cord itself. Both of these conditions are rare in rabbits. Infections of the inner ear are much more common and can also lead to hind limb weakness, but is usually also associated with a pronounced head tilt. Please refer to the article on Head Tilt and Other Neurological Diseases in House Rabbits for more information on this condition.

Signs - The signs of infection in the central nervous system depend on the area being affected and the severity of the infection. The signs can include: depression, loss of appetite, high fever, collapse and partial or complete paralysis of the extremities.

Diagnosis – A complete blood cell count may show an increase in the number or types of white blood cells, but this test is not specific for bacterial infections. A more specific diagnostic test is to take a sample of cerebrospinal fluid and examine it microscopically for abnormalities. An X-ray or CT may show abnormalities of the middle ear (which can be related to disease of the inner ear).

Treatment - The treatment for a bacterial infection of the inner ear or central nervous system is antibiotics. The rabbit may need intensive care in the veterinary hospital including IV fluids and IV antibiotics. The prognosis for central nervous system infection is guarded. The prognosis for an inner ear infection is better, but in both cases there can be permanent nerve damage that may impair the rabbit's life style. As mentioned, nerve tissue takes a long time to heal and it may be weeks to months before any healing is apparent.

NEOPLASIA (CANCER)

Cause - Other than the high incidence of uterine cancer in female rabbits over two years of age, neoplasia of other organs is less common in rabbits than in other species such as humans, ferrets and dogs. The next most common cancer of rabbits is lymphoma that can develop anywhere in the body and at any age. This cancer has been found in the spinal column where it causes damage to the spinal cord and the surrounding bone. Other malignant cancers, such as uterine adenocarcinoma, can spread all over the body including the bony spinal column. Primary bone cancer has also been seen in the rear legs of rabbits, which also leads to hind limb weakness.

Signs - The signs of cancer can be variable depending on the tissues being affected and may develop gradually or may appear suddenly.

Diagnosis - A diagnosis of cancer is may be suspected on a x-ray and then confirmed with a biopsy of the affected tissue. Cancer in the brain or spinal tissue itself is more difficult to detect.

Treatment - Chemotherapy can be attempted if it is appropriate for the particular cancer. Another option is radiation therapy if you have such facilities in your area. If the cancer is in an extremity, it may be possible to amputate the limb to save the rabbit. Corticosteroids can sometimes slow the growth of the cancer and can be used to prolong life for a while.

SYSTEMIC DISEASE

Any disease of a rabbit that causes it to feel weak can cause hind limb weakness and can be confused with a true neurological disease. Bunnies that are anemic or have heart disease, for instance, will not be able to get enough oxygen to their brain or muscle tissue and may appear weak and wobbly, particularly after exercise. Rabbits with liver or kidney disease can develop a buildup of metabolic toxins in their blood that interfere with normal brain and muscle function and thus leads to weakness. Malnutrition or a severely imbalanced diet can also lead to a generalized weakness. For instance, a lack of sufficient Vitamin E can lead to a type of muscular dystrophy and the inability to move properly.

Any disease of a rabbit that causes pain on movement may be incorrectly interpreted as hind limb weakness. For instance, pododermatitis (ulcerated feet) causes pain on movement, therefore the rabbit may sit hunched all day in its cage and appear to t be unable to walk. Arthritic conditions of the spine, hips, knees or hocks can cause an inability to move normally. Rabbits that are experiencing an intestinal shutdown either mechanically from an obstruction or physiologically from disease or inappropriate diet are often immobile due to the pain of the gas-filled intestinal tract and ultimately weakened by the disruption of the blood electrolyte balance.

The diagnosis of any of these diseases depends on a combination of a good physical exam and history, and various diagnostic tests. The treatment, of course, is dependent on the diagnosis.

CARE OF THE WEAK RABBIT

Rabbits with hind limb weakness will need special care. The following is a list of some of the considerations you will need to make.

• Long term commitment is necessary for the care of the rabbit with neurological disease. None of these diseases are going to be “quick cures”. Many will take weeks to months to see any positive results.
   
• Decubital ulcers (“bed sores” are caused by sitting in one place too long or from soiling by stool or urine)

  Solution: Keep your pet on soft absorbent bedding and move positions often. Use protective creams or ointments and bandaging as necessary. Bath anal area as needed and dry thoroughly after the bath
   

• Damage to eye(s) when rabbit is falling or rolling

  Solution: provide cage padding - cover wire floors and walls, use eye ointments as needed to protect eye and treat dryness. Remove toys or items that the toenails could get caught in - keep the nails trimmed - experiment with using smaller cage or exercise areas until the pet is more stable.
   

• Joints become stiff or muscles atrophy

  Solution: You will not be able to counteract all of the damage because if there is no nerve innervation to the area, the tissue will eventually contract and become hard and useless. However, physical therapy several times daily for a few minutes can be very helpful. Gently flex and extend the joints at least 20 times at a session. In addition massaging the muscles prior to stretching helps to warm and loosen them.
   

• Handling can be stressful to the pet especially if there is a loss of balance

  Solution: Short handling sessions and minimal handling until the pet adjusts to the condition. Many pets over time actually get calmer when certain people handle them. Keep the pet close to the floor or in a secure area when handling in case they loose their balance or jump unexpectedly.
   

• Inability to reach cecotropes - some rabbits cannot reach the anus to eat the cecotropes which are necessary for a healthy diet

  Solution: You will recognize these vitamin rich droppings because of their shiny mucous coat, stronger smell and unusual shape. Collect these whenever they appear and place them in or near the food area. Most rabbits will eat them on their own. Many rabbits learn to find them on their own in the cage. This is another reason not to have a wire cage floor which will allow the cecotropes to drop out of the rabbit's reach.
   

• Inability to use food and water containers

  Solution: Experiment with what is most comfortable for your pet. It might be necessary to attach these containers to the side of the cage so the rabbit doesn't keep pushing them around. Some rabbits can no longer use water bottles, so provide a bowl with shallow water. It may be necessary to elevate or use wider mouthed bowls to make feeding easier.

CONCLUSION

There are many possibilities for hind limb weakness in a rabbit and often the diagnosis cannot be reached without some investigative work. Some of the conditions discussed are treatable and others are not. You can help tremendously by being observant and even taking notes so you remember the details of your pet's illness or unusual behavior. This information is invaluable in determining a diagnosis, a treatment regimen and ultimately the prognosis for your pet.

revised 3/07/01

Date Published: 3/7/2001