The twisting of liver lobes
The liver in rabbits has six lobes, which can partially twist around their own axis, a condition known as lobar torsion of the liver.
The anatomical structure of the liver:
- Left lobe (Lobus sinister): Divided into the medial and lateral parts (Lobus sinister medialis and lateralis).
- Right lobe (Lobus dexter): Divided into the medial and lateral parts (Lobus dexter medialis and lateralis).
- Caudate lobe (Lobus caudatus): Contains the caudate process (Processus caudatus) and the papillary process (Processus papillaris).
- Quadrate lobe (Lobus quadratus).
The caudate lobe of the liver is particularly affected by liver lobar torsion in rabbits.
The issue with this condition is that the symptoms are very nonspecific, making it difficult to diagnose early in many rabbits. However, early diagnosis is crucial because if left untreated, it can lead to death.
Why is this the case?
The twisting of the liver lobe causes the vein to become blocked, leading to thrombosis and tissue breakdown. As a result, the affected tissue no longer receives blood supply, and toxins enter the bloodstream.
Causes: How does liver lobar torsion develop?
- Dwarf rabbits with brown spots appear to have a predisposition for liver lobar torsion.
Liver diseases such as liver injury from falls or other causes (trauma), neoplasms, liver infections, or liver coccidiosis.
- Gastrointestinal diseases, especially conditions like (repeated) gastric dilatation and intestinal diseases, particularly blockages, are suspected causes for the twisting of liver lobes.
- There is ongoing discussion whether dwarf rabbits, especially white rabbits with brown markings (Basseches, 2014), have a genetic predisposition for liver lobar torsion.
A potential connection with megacolon has also been suggested, as frequent digestive disorders may predispose to liver lobar torsion.
Symptoms: How does liver lobar torsion manifest?
- Refusal to eat and general malaise are often still incorrectly attributed to digestive disorders. Many rabbits exhibit symptoms similar to gastrointestinal issues, such as gastric dilatation, which unfortunately leads to liver lobar torsion often going undiagnosed.
- The refusal to eat causes the stomach contents to stagnate, leading to potential gas buildup (bloating), and many rabbits may die suddenly due to this complication.
- Some rabbits with liver lobar torsion show recurrent gastric dilatations, which can be a clue to the condition.
- There are also cases where rabbits die suddenly without any symptoms at all.
Possible common symptoms:
- Refusal to eat and gastric dilatation with bloating.
- General malaise and pain (no comfortable position).
- Poor circulation status: pale mucous membranes (sometimes also jaundiced mucous membranes), dehydration, low body temperature, rarely elevated temperature, rapid heart rate.
- Pain upon palpation of the cranial abdomen, with a mass palpable on the right side.
- Reduced fecal output and sometimes soft stools.
- Rapid breathing
Diagnosis: How can it be determined that a rabbit has liver lobar torsion?
- Sometimes, swelling of the liver can be visible in the X-ray of the right caudal abdomen.
- The veterinarian may be able to palpate the swollen liver on the right side of the stomach.
- Ultrasound is an excellent method for diagnosing liver lobar torsion, provided the veterinarian is experienced in ultrasound diagnostics.
- Liver values in the blood can sometimes show abnormalities (such as ALT and AST, less often γ‑GT). However, they are often completely normal, and abnormalities can have many different causes.
- Affected rabbits frequently show signs of anemia with reduced hematocrit levels.
Treatment: How is it treated?
Without surgery, only a small percentage of rabbits (44% in one study) recover with medication treatment. However, the surviving rabbits often suffer from digestive disorders (such as gastric dilatation) due to ongoing pain. On the other hand, surgically treated rabbits (undergoing lobectomy) all recovered and returned to health.
Stabilization until surgery:
- Warming in case of low body temperature.
- Warm intravenous infusions to help stabilize circulation.
- Strong pain relief (e.g., opioids).
- Antibiotics (e.g., Enrofloxacin) to prevent infection.
- Metoclopramide (MCP) to support gastrointestinal motility.
- Liver protectants (as used for liver diseases).
- Additional supportive measures as for gastric dilatation if needed.
- In cases of severe anemia, blood transfusions may be required.
The Surgery (Lobectomy):
Once the rabbit’s circulation has been stabilized, the twisted liver lobe can be surgically removed. The surgery generally has a good prognosis, and complications are rare. However, the rabbit must stay in the clinic until it has fully recovered and stabilized after the procedure.
Sources and Further Reading:
Basseches, J. (2014): Liver lobe torsion in pet rabbits. Vet Clin North Am Exot Anim Pract, 17, 195.
Eckert, Y., & Thöle, M. (2019): Verdreht–Leberlappentorsion, eine unterschätzte Erkrankung beim Kaninchen?. kleintier konkret, 22(S 02), 2-9.
Graham, J. E., Orcutt, C. J., Casale, S. A., Ewing, P. J., & Basseches, J. (2014): Liver lobe torsion in rabbits: 16 cases (2007 to 2012). Journal of Exotic Pet Medicine, 23(3), 258-265.
Graham, J., & Basseches, J. (2014): Liver lobe torsion in pet rabbits: clinical consequences, diagnosis, and treatment. Veterinary Clinics: Exotic Animal Practice, 17(2), 195-202.
