Gastric Dilation in Rabbits
Gastric dilation is a syndrome in which the stomach expands (dilates) due to excess gas and fluid, resulting in complex local and systemic changes in the digestive tract. In most cases, it occurs due to foreign body obstruction. In rare instances, the stomach dilates in the absence of a foreign body. In either case, a mechanical or functional obstruction occurs at the opening of the stomach into the intestine, and fluid or semi-digested food accumulates in the stomach.
Twisting of the stomach, a condition called gastric volvulus, is rarely seen in concurrence with distension, but has been reported. More commonly, the pressure due to distension will result in a lack of blood supply and pressure on the nerves. These changes may account for acute (sudden and severe) clinical signs, such as severe abdominal pain, shock, and even heart failure.
Symptoms and Types
Although weakness and/or collapse are the most common historical findings associated with gastric dilation, rabbits may also have a history of loss of appetite. Other common symptoms include:
- Irregular blood pressure and heart rate
- Severe abdominal pain on palpation
- Progressive abdominal distension (does not happen suddenly)
- Hypovolemic shock (e.g., pale mucous membranes, decreased capillary, weak pulses, low body temperature)
Gastric dilation commonly occurs due to an obstruction caused by the swallowing of hair mats, cloth, or other fibers. Ferrets may also obstruct the pathway by swallowing small pieces of rubber or plastic toys, though it occurs less frequently. A low fiber diet can increase cravings for fiber-rich foods and lead to chewing of the aforementioned objects, increasing the risk of intestinal obstruction. Abdominal scar tissue is another posible cause for gastric dilation.
You will need to provide a thorough history of your rabbit's health leading up to the onset of symptoms to your veterinarian. He or she will then perform a thorough physical exam on the animal in the attempt to differentiate from other causes of abdominal pain, distention and appetite loss. The best method by which to make a diagnosis will be by visually examining the stomach cavity, which may be done by X-ray, ultrasonography, or endoscopy. The latter method uses a small camera that is attached to a flexible tube, and which can be inserted into the actual space to be examined. In this way, your veterinarian can get a more precise image of the cause of the blockage, and if indicated, take a tissue sample for biopsy.
As part of a standard physical examination, your doctor will also do a complete blood profile, including a chemical blood profile, a complete blood count, and a urinalysis. Blood and urine analyses, meanwhile, may show evidence of low blood volumes, an indication that shock has, or will set in.