Simethicone

Question
QUESTION: Hello, a quick question on Simethicone (Rid wind). There seems to be a disagreement in rabbit forums about giving Simethicone if there's TOTAL obstruction in the gut. May I please know your views on this? And how do you know if it's total obstruction since I presume that it has similar symptoms as gas (perhaps minus the gurgling sounds).

I am asking this because I have made several "emergency" trips to the vet in the past only to end up with a ridiculous bill and be sent home with some Cisapride and Simethicone.

ANSWER: Dear Sue,

If there is a total obstruction of the stomach (gastric obstruction, leading to gastric bloat), then simethicone is probably not going to help, depending on what is causing the obstruction.  A tiny amount of simethicone won't really add much to the contents of the stomach, though it might help reduce the foaminess.  But since rabbits can't burp, that won't help.

The ONLY thing simethicone might do for a gastric bloat is possibly help lubricate a physical obstruction at the pyloric sphincter.  But that's not very likely.  Once the stomach is truly bloated, its volume will pinch off the small intestine just caudal to the stomach, where the small intestine takes a very sharp turn.  No amount of simethicone will help that.

An obstruction of the lower GI is bad, but not as bad as a gastric bloat.  In this case, simethicone can actually help by lubricating whatever is blocking the intestine (LOTS of oral fluids also can help; consult your vet as to how much can be given safely).  It also can help reduce the foaminess of intestinal gas, making it easier to pass (and possibly easier to pass around a partial obstruction).

You can't mistake a gastric bloat for anything else:  the rabbit's abdomen will inflate to horrifying proportions in a relatively short time, be as hard as a watermelon, and--once advanced--impossible to reverse without intubation or even surgery.  (Though there will be no time for surgery.  A bloat can kill very quickly.)

An intestinal obstruction is harder to diagnose, as there will usually not be significant bloating.  But the GI tract will often be static *caudal* to the obstruction, while working madly to push *cranial* of the obstruction. Your vet may or may not be able to hear this on auscultation, since the intestine coils around in the abdomen.

If in doubt, you might consider this:

http://www.bio.miami.edu/hare/enema.html

Since the enema goes up the rear, it will not make things worse, and can often help loosen and move an intestinal obstruction.  An enema will have no effect on a gastric bloat.

Hope some of this helps.

Dana

---------- FOLLOW-UP ----------

QUESTION: Thanks for your reply. So when one actually hears loud noises from the stomach, what is that actually? Stomach or intestinal GI? What are the likely causes of stomach/intestinal obstructions? As I understand, Simethicone etc are meant to treat only the symptoms.  

From the internet, Simethicone seems to be inert. That it is not absorbed by the rabbit. If that is the case, why can't it be given long term? (internet also suggested that it's not safe to do so). Our bunny is on a Metachlopromide for long term but seems to get stasis ever so often.

Answer
Dear Sue,

The loud noises you hear in the intestine is the movement of gas bubbles and intestinal contents being pushed around by the muscles of the intestinal wall.  Those muscles are sloshing things around, and it makes noise.  In most cases, you're hearing intestinal movement, though I suppose gas and contents in the stomach could make noise, too, if the stomach muscles pushed it around.

Stomach obstructions can be caused by
1.  foreign body
2.  ingested hair wadded into a very tight ball (unusual, but not impossible)
3.  stomach expanded with gas or fluid enough to pinch off the intestinal turn just caudal to the pyloric sphincter
4.  other mysterious causes

Intestinal obstructions can be caused by
1.  foreign body
2.  stenosis of the intestine from scarring (rare; seen mainly in "megacolon" bunnies)
3.  insert unknown cause here

Simethicone is a relatively inert substance that is NOT absorbed through the intestinal wall.  However, it can coat the intestinal lining and interfere with nutrient absorption, which is why it's not recommended to be given long-term.

If your bunny is getting chronic bouts of GI slowdown/stasis, it's time to explore the reason(s) why.  Ileus is a symptom of a problem, not a primary disorder.  The most common triggers of ileus are improper diet:

http://www.bio.miami.edu/dana/diet.html

and pain/stress from dental problems, such as molar spurs:

http://www.bio.miami.edu/dana/dental.html

Other sources of pain/stress also can trigger ileus.  Bacterial infection (with fever), urinary tract problems (urolith, bladder sludge, bladder infection), or almost anything that causes pain/stress can cause the GI tract to slow down or shut down.  Please see this for more complete information:

http://www.bio.miami.edu/hare/ileus.html

I would have your bunny checked for dental problems by a very experienced rabbit vet, as this is a very common cause of chronic GI stasis.  

I hope this helps.

Dana