Rabbits are frequently diagnosed with gastrointestinal (GI) stasis. However, some of these rabbits may be suffering from an intestinal obstruction, which has an acute onset and requires rapid and very different treatment to GI stasis in order to have a chance of a successful outcome. Although intestinal obstruction is rare in pet rabbits, it is considered an emergency and should be addressed promptly.
Intestinal obstructions in rabbits
House rabbits may have access to many items such as small pieces from children’s toys, carpet, cables, plastics and buttons on remote controls, etc. Any of these can seem appealing to rabbits and may not be noted as missing by owners until closer inspection after the rabbit starts showing clinical signs of being unwell.
Clay based clumping cat litter, if used in litter trays, can also be ingested and cause obstruction. For this reason only non-clumping cat litter, such as compressed wood shavings should always be used in rabbits litter trays.
Rabbits may also eat items that are part of their daily diet which could cause an obstruction. The seeds from apples, locust beans which used to be common in muesli type rabbit foods, and pieces of sweet corn have all been cited as causes of intestinal obstruction in rabbits. However, in order to develop an obstruction a concurrent underlying disease, such as dehydration or reduced gut motility must be present.
Nowadays though, apples, muesli and sweet corn are not considered part of a healthy diet for rabbits.
It was long thought that hairballs were a primary cause of gastrointestinal stasis and obstruction in rabbits. However, it is now believed that the vast majority of rabbits have some degree of hair matter within their stomach. This is a normal finding and occurs during usual grooming, especially during moults.
If the rabbits gastrointestinal tract remains healthy, and the motility is not compromised, this hair is passed out with the faeces in small quantities and doesn’t cause any problems.
If the rabbits gastrointestinal tract slows down as a consequence it begins to dehydrate, then the accumulated hair can begin to matt together and has the potential to cause an obstruction. Therefore the primary issue is why the rabbits gastrointestinal tract has slowed down, but the secondary problem of the hairball causing a blockage needs immediate veterinary attention.
Often the rabbit will exhibit normal behaviour and then suddenly develop an acute and rapid onset of clinical signs. Rabbits with an intestinal obstruction present severe abdominal pain and as a result will become anorexic, unwilling to move and grind their teeth in pain (bruxism). They will also press their abdomen on the ground, have a bloated and distended abdomen, and cease production of faecal pellets.
Sometimes all of these symptoms may be apparent, but this is not always the case, and for this reason it is not always possible to immediately make a diagnosis of intestinal obstruction.
Clinical examination can show an enlarged part of intestine. This is often made on radiographic findings, which will show a large halo of gas or collection of fluid proximal (before) the site of the obstruction. Sometimes it may be possible to see the item causing the obstruction, but this depends what the object is made up of as certain materials do not show up on x-ray. In this case, it is possible to perform a contrast study. A liquid that will show up on x-rays is introduced to enhance the gastrointestinal tract and identify the type and the location of the obstruction in order to facilitate the surgical removal of the object.
The radiographic examination is generally taken under sedation unless the rabbit is very quiet and unwilling to move. Sedation also helps to reduce the stress caused by the handling in such stressful and painful situations.
In severe cases, sometimes exploratory laparotomy (surgical abdominal exploration) under general anaesthesia is performed in order to evaluate the nature and severity of the obstruction that otherwise will not be possible to investigate.
Once a diagnosis of intestinal obstruction is made, the rabbit will need emergency medical and surgical treatment to remove the offending blockage.
Medical treatment consists of administration of painkillers (analgesia), fluid therapy and gastric decompression to release the trapped gas using a tube that is passed through the mouth into the stomach. The use of gut motility stimulants (prokinetics) in this case is contraindicated. Prokinetics encourage movement of the gastrointestinal tract, resulting in a rupture of the intestines or stomach which is likely to prove fatal.
Surgical treatment consists of removal of the obstruction under general anaesthesia. This procedure is performed once the rabbit is considered stable from a medical point of view in order to reduce the risk of the general anaesthesia and increase the success of recovering.
The prognosis is generally guarded and is dependent upon several factors. The time elapsed between the occurrence of the obstruction and surgery to remove it is possibly the most important factor. If the obstruction just happened and the intestine has not deteriorated, the prognosis is guarded but favourable. If, however, part of the intestine needs to be removed, the prognosis is generally poor.
However, if the problem is addressed promptly and the intestinal obstruction is not too severe, there is a good chance that once the surgery has been performed, the rabbit will survive.