Carmela: acute bloat in a 3 years old rabbit
Rachel Ihlenfeldt and Barbara Schmeitz
MediRabbit.com is funded solely by the generosity of donors.
Every donation, no matter what the size, is appreciated and will aid in the continuing research of medical care and health of rabbits.
Bloat is a most disturbing and life-threatening condition in rabbits. It happens suddenly, without any warning, and leads to a rapid accumulation of gas in the stomach (tympany) and extreme distension of the wall of this organ. The stomach feels hard and the rabbit looks like a “balloon”. When bloat reaches a certain stage, the situation is irreversible and fatal. The stomach wall of rabbits is not as elastic as in many other animals. Moreover, the distended stomach will compress the main blood vessels that surround this organ and lead blood to and from the heart. Blood flow becomes irregular, and rarely, blocked, causing disturbances of the cardiac rhythm, cardiovascular collapse and/or cardiac failure. Blood electrolyte imbalance and pain may lead to convulsions and epilepsy-like attacks in the terminal stages of the condition.
Causes of bloat remain unknown. It is suspected that in most animals bloat may be related to overeating and/or exercising immediately after eating. Additional causes may be a lack of fiber in the diet, a change in the diet, excessive drinking, dehydration, or stress. Recent necropsy studies concluded to pre-existing problems prior to bloat, such as necrotic tissue at the opening between the stomach and the duodenum (pylorus), presence of gastric ulcers or bleeding of the stomach wall.
The rabbit is in terrible pain. Pain indicators include moaning, grunting, and grinding teeth. A rabbit may take an object into her mouth and bite down hard on it. Rabbits suffering from bloat are often dehydrated and will refuse to eat or move. The rabbit may appear depressed, sitting in a hunched position in one spot or in a litterbox. Some rabbits will "crash" their heads into their abdomens, where it hurts. Others may suffer breathing difficulties due to the lungs being compressed by the distended stomach. Most bloated rabbits are hypothermic.
The best and safest diagnostic tools for bloat are a physical examination (palpation, hard distended abdomen, low body temperature) and radiography. Since the pressure of the bloated stomach on blood circulation and organs is life-threatening, the rabbit must be stabilized and given a treatment for shock and hypothermia including pain relief medication and lukewarm intravenous fluids (never subcutaneous as the hypothermic body is unable to absorb these properly) before taking abdominal radiographs.
Bloat should not be misdiagnosed for cardiovascular collapse and heart failure. Indeed, bloat often leads to secondary cardiac conditions.
Carmela, rescued from a backyard breeder, was about 3 years old when she developed acute bloat. The following radiographs were taken at Gulf Coast Veterinary Hospital about 8 hours after Carmela was intubated. In both views, she presents an extremely distended stomach, compressing her heart, lungs, and other organs. Despite getting immediate veterinary care, Carmela could not be saved and was humanely euthanized to relieve her suffering.
Bloat is an emergency situation. If it is suspected that a rabbit is suffering from bloat, whether or not the rabbit is hypothermic, remove all food from the rabbit's area to avoid overloading an already distended stomach and a compromised digestive system.
Emergency veterinary intervention is necessary by a rabbit-knowledgeable vet. Still, prognosis for acute bloat is poor and most bloated rabbits do not survive longer than a few hours to a day after diagnosis. Steroid pain medication, fluids, antibiotics and anti-foaming agents (e.g. simethicone) bring little to no relief.
Analgesic drugs for use in rabbits are described here.
Putting the rabbit on its side and gently massaging its abdomen in the direction of the anus may help. A handful of rabbits were saved after intubation with a rubber catheter and aspiration of the content and gas of the stomach. The majority died within 24 hours after relieving the pressure on the stomach. Rarely, difficult intubation or repositioning of the catheter tube due to clogging by food particles led to excessive vagal stimulation, swelling of the tissues in the throat and caused a rapid death of the rabbit.
In memory of Carmela, who suffered a terrible episode of bloat on May 1st, 2010.
Many thanks also to Esther van Praag, Ph.D. (Switzerland) for the medical information, to Debbie Hanson (USA) and the Gulf Coast Veterinary Hospital (1111 West Loop South, Houston, Texas, USA) for their contribution and permission to use the radiographs of Carmela.