By Amber Wheelbarger, DVM >>>
It was a day like any other. I woke up, listened for the dog next door, and thought about looking for a bite to eat. Suddenly, I discovered I could not move my head correctly and I had a horrible headache. The world was sideways. And the more I tried to look around, the more the world started to spin. I couldn’t make it stop. I tried to move, but couldn’t, so I just sat there, as still as I could, and closed my eyes hoping that would fix it, but it didn’t. I wanted to eat, but just getting to my food was impossible and the idea of eating made me feel sick. I needed help!
For a rabbit, this sudden loss of control must be terrifying and confusing. Unfortunately, it is a very real condition and one of the more common medical conditions we see in our pet rabbit veterinary practice.
Rabbits are popular pets today, partly because they work well indoors and can live in smaller environments often found in the suburbs and cities. They are small in size, can be litter-trained and are full of fun antics. However, one of the more common health conditions we treat them for is "sudden head tilt," also called wry neck or Labyrinthine Torticollis.
Rabbits with wry neck will suddenly have a dramatic cock of the head that they cannot correct, and sometimes they have rapid eye movements from side to side. At times they twist so much that they spin around and around, seemingly unable to stop. Head tilt can have many possible causes and should be seen by a veterinarian skilled in rabbit care as soon as possible. Sometimes an early diagnosis and treatment can dramatically improve the outcome for your rabbit friend.
There are many possible causes of this type of neurological disease, but it's usually an infection of the inner ear or a brain infection from a parasite called Encephalitozoon Cuniculi. A rabbit can contract sudden brain tilt from brain cancer or trauma to the head or vertebral column, though it is less likely. When examining a rabbit that has exposure to the outdoors, we consider overheating, heavy metal toxin exposure, or even larva migration through the brain of either the cuterebra fly or roundworms. These are rare causes, but depending on the rabbit’s lifestyle, they may need to be considered, especially if the other possibilities are eliminated by testing.
For a veterinarian, every case is like a mystery. We work to find out which of the possible disease suspects is causing the odd behavior, starting with the rabbit’s life story -- where it is housed and other animals sharing its environment. Next, we do an exam and look for signs of an ear infection or other symptoms that may point us in one of the above diagnostic directions. However, sometimes there are no outward signs to assist our diagnosis, so we have to recommend tests.
An X-ray is a good place to start. It is a means to note changes to the skull or help detect spine trauma or disease. An X-ray of the skull also looks at the bone structure of the inner ear for signs of an infection, the number one cause of head tilt. In larger specialty hospitals, MRI or CT scans can also be used for this and can identify earlier or subtler changes than a standard X-ray. As part of the workup for a sick patient we usually also recommend general blood and urine testing. This looks at white and red blood cell counts and blood chemistries to assess organ disease and changes in electrolytes. This can help identify systemic diseases that may be involved, as well as provide a more accurate prognosis.
In addition, a few specific tests can be run to further help us narrow down the list of possible suspects. An Encephaloitzoon cuniculi infection is a widespread, but often hidden, parasitic brain disease in pet rabbits. By some estimates, it affects 50-75 percent of rabbit colonies, but does not always cause noticeable disease. It is a single cell protozoan parasite. Rabbits are usually infected by their mothers, but can remain symptom-free for years. We can check for it with a blood test where we look for elevated antibody levels. If positive, we can attempt to eliminate it with medications, but success is variable, because sometimes the parasite has already caused damage to the brain and the main symptoms may be the result of the secondary inflammation that the parasites cause. Other tests that are often recommended are cultures of a suspicious ear infection or nasal infection that might have spread to the brain. This test will tell us not only what the possible cause of the head tilt is, but what antibiotics will work best to treat it. Other blood antibody tests may be run as well.
Finding a diagnosis is only part of the process in treating a pet rabbit for head tilt. Part of caring for a rabbit with this condition is medication aimed at the probable or diagnosed cause. The other part is tender loving care. Wrapping these bunnies in towels to prevent them from spinning and hurting themselves further is often necessary. Also, if the rabbit is too wobbly to get to its food, it may be necessary to help them eat. This sometimes means hand-feeding them pureed food and water by syringe. They may need medications to help improve their appetite or treat seizures caused by the brain disease. It can take days to weeks of intensive care to help a bunny during this type of crisis. It can be done at home if the rabbit’s owner has time to commit to it, or these rabbits may be hospitalized for nursing care. Unfortunately, not all rabbits with the condition respond to medication. When rabbits with severe symptoms do not improve despite intensive care, euthanasia may be recommended to ease their suffering. It is a sad fact of this condition; however, the majority of these cases do at least show a halting in the progression of symptoms if we treat them soon enough; and many will show a complete recovery with proper treatment.