If a rabbit has a crooked head posture, it will most often be a symptom of an illness. It can be caused by, for example, otitis media, a blow to the head or something else. Most often, however, it is a parasite called E. cuniculi that causes the symptom. The parasite was originally named Encephalitozoon cuniculi, which causes the crooked head position and balance problems in rabbits. It is actually not so few rabbits that have this parasite, it is up to 50-80% of all rabbits that have it, studies show. However, it is only in a few that the symptoms unfold.
The parasite is a zoonosis, which means that it is a parasite that is also seen in other animals and humans. The parasite can therefore spread between different animals and be transmitted to humans. However, it is most often people with diseases who become infected with the parasite - it must be added here that no cases of infection from rabbit to human have yet been seen.
The infection occurs through contamination of feed or water and spores are excreted in the urine. In addition, fetuses can have the parasite transferred from the mother when the fetus is inside the womb.
In addition to crooked head posture and balance problems, symptoms can include coma, incontinence, tremors or paralysis in the legs. The way you as an owner can tell if your rabbit is getting the previously mentioned symptoms is to see if your rabbit goes in circles, if your rabbit has a crooked posture and shakes a little or has more spastic movements where they can't control it.
The reason for these types of symptoms is that the parasite settles in the nervous system, but it can also occur in the eyes or kidneys. There may be some slightly different symptoms such as cataracts, white spots in the eyes and kidney failure.
The diagnosis is made
The vet can make the diagnosis by taking a blood sample, as the parasite will form antibodies which are secreted into the bloodstream. It can be ruled out that the rabbit has the parasite if the blood test is negative. The positive blood test can only show that the rabbit has been exposed to the parasite, but it can be seen from a blood test with high values, in conjunction with clinical symptoms, that the rabbit should start treatment against the parasite. As the parasite E. cuniculi is so widespread among rabbits, the diagnosis is more uncertain for low values.
If you start treatment early, you can have a good effect on those infected with the parasite with the dewormer fenbendazole. Sometimes the parasite is completely removed, other times it attacks again. Unfortunately, a few times the treatment does not work at all, which cannot be explained why.
The treatment works if there are signs of improvement within a week - however, it is important to always take the full course.
In some special cases, the parasite is very aggressive, which will also appear clearly from the rabbit's symptoms, for example by not even being able to eat itself. Here, careful care or admission to an animal hospital is necessary.
- To protect the rabbit, you can put your rabbit in a small box with high sides, which can give it a safe feeling if it were to move. In addition, a synthetic soft lamb skin can be good to put at the bottom, which can absorb the rabbit's urine.
- You can give it hay or greens by hand feeding it, as it can be a challenge for it to eat on its own. Remember to feed it frequently.
- One eye (facing the substrate) may tend to dry out on the cornea, so it must be lubricated with ointment.
It can be a tough process, which requires something from you as the owner, but by doing your best, good results can be achieved. Fenbendazole treatment can heal very well after an attack, but unfortunately not everyone does, and in those cases, the rabbit must unfortunately be euthanized.
In some cases, there is a middle way, where the rabbit recovers, but suffers in the form of a crooked head position for the rest of its life, which is not harmful to the rabbit as such.
Unfortunately, since it is a parasite, a vaccine cannot be produced.
There is a fairly high probability that a rabbit will get E. cuniculi, as it is a widespread parasite among rabbits. Among them, dwarf rabbits are more often affected than larger breeds.